Trends in cervical cancer and its precursor forms to evaluate screening policies in a mid-sized Northeastern Brazilian city.

Cervical cancer is a health issue that disproportionately affects developing countries, where the Papanicolaou test (Pap smear) remains an important screening tool. Brazilian government recommendations have focused screening on the female population aged from 25 to 64 years old. In this study, we examined the incidence and mortality rates of invasive cervical cancer lesions and the incidence rates of in situ precancerous cervical lesions, aiming to calculate their respective statistics over time in a mid-sized Brazilian city, Aracaju. The 1996-2015 database from the Aracaju Cancer Registry and Mortality Information System was used to calculate age standardized rates for all invasive cervical tumors (International code of diseases, ICD-10: C53) and preinvasive cervical lesions (ICD-10: D06) in the following patient age ranges; ≤ 24, 25-34, 35-44, 45-54, 55-64 and ≥ 65 years old. We identified 1,030 cancer cases, 1,871 in situ lesions and 334 deaths. Using the Joinpoint Regression Program, we calculated the annual percentage incidence changes and our analyses show that cervical cancer incidence decreased up to 2008, increased up to 2012 and decreased again thereafter, a significant trend in all age groups from 25 years. The incidence of precursor lesions increased from 1996 to 2005 and has since decreased, a result significant in all age groups until 64 years. Cervical cancer mortality has decreased by 3.8% annually and trend analysis indicates that Pap smears have been effective in decreasing cancer incidence and mortality. However, recent trends shown here show a decreasing incidence of in situ lesions and may indicate either a real decrease or incomplete catchment. Thus, we suggest health policies should be re-considered and include sufficient screening and HPV vaccination strategies to avoid cervical cancer resurgence in the population.

Introduction

Cervical cancer still has high rates of incidence and mortality, despite the epidemiological transition having occurred in many countries. Statistics show regional variation and are dependent on the human development index of the area[1]. The main causative agent of cervical cancer is Human Papilloma Virus (HPV) types 16 and 18. As such, it has been inferred that HPV vaccination, together with screening using the Papanicolaou test (Pap smear) and HPV DNA identification[2][3][4], is important to reduce incidence and mortality rates. However, it is necessary to evaluate the outcomes from past and current health programs for future comparison with programs that include HPV vaccination.

The two major histological subtypes of cervical cancer, squamous cell carcinoma and adenocarcinoma, are equally dependent on HPV infection and the diagnosis and treatment of their preinvasive forms is crucial to blocking transformation into invasive carcinoma[5].

Screening for cervical cancer has the greatest impact in the 25–65-year-old age group[6]. In Brazil, government protocols in 1998 recommended to start screening patients when they are between 35 to 49 years old. From 2011, this was updated to begin screening people from 25 years old and stop when they are 64, after at least two negative tests in the five years prior, and the HPV vaccination program began in 2014[7]. However, varying regional development has led to differences in patient recruitment for screening, access to health services and the quality of mortality data. These issues hinder evaluations to assess the impact of screening on the incidence of cervical cancer and associated mortality in Brazil[8].

The purpose of this study is to estimate the impact of Pap smear screening on the trends in incidence of invasive and preinvasive cervical cancer lesions, and associated mortality, to determine whether public policies have been effective. We hypothesize that increased identification of preinvasive lesions and subsequent intervention will lead to reduced incidence of invasive neoplasms, and consequently, reduced mortality rates. The assessment of vaccination results, which might also improve control, needs to be undertaken.

Materials and methods

The population used in this study was that of the municipality of Aracaju, Sergipe, Brazil estimated at 648,939 in 2018, with approximately 320,000 women at risk per year.

We used data from the Aracaju Cancer Registry from 1996 to 2015 to calculate incidence rates. The cancer registry actively collects information from Aracaju hospital records, accesses the databases of all pathology and cytology laboratories in Aracaju, and links to several official health information databases, including information on cervical cancer screening. To determine mortality rates, we used all-cause mortality data from the Brazil Mortality Information System for the same period. The Aracaju Cancer Registry was established in 1998 and contains a comprehensive and internationally validated dataset from this date.

The registry records in situ lesions as invasive if there have been two positive diagnoses in less than one year. We did not calculate mortality for carcinomas in situ because the risk of death is only substantial at high ages, independent of age at diagnosis, indicating alternative primary causes. We have used all-cause mortality, not stratifying cause-specific deaths.

We included all cases of cervical cancer and preinvasive lesions according to the International Classification of Diseases, 10th Revision (ICD-10), C53, D06 and N87.2. Invasive lesions were defined as squamous cell carcinoma (morphology: 8010–8560, 8050–8052, 8070–8076, 8082 and 8123); adenocarcinoma (morphology: 8140, 8231, 8255, 8260, 8310, 8380, 8384, 8430, 8440, 8441, 8450, 8460, 8480, 8481, 8490, 8570, 9110); and others (morphology: 8000, 8010, 8013, 8015, 8020, 8041, 8090, 8200, 8246, 8560, 8574, 8720, 8800, 8810, 8830, 8890, 8900, 8910, 8920, 8933, 8935, 8950, 8951, 8980, 9473). In situ lesions were defined for morphologies 8010–8560). Malignant neoplasms of the uterine body (ICD-10 C54) and malignant neoplasms of an unspecified portion of the uterus (ICD-10 C55), were excluded from the analysis.

We calculated the age standardized rates (ASRs) of the whole population for incidence and mortality in each year using the direct method of standardization, which combines the population’s age specific rates with the composition of a standard population; here, the number of individuals by five-year age groups to a total of 100,000. This is a correction to the age structure of the world population. It resulted in weighted age-specific rates to reflect the number of events if the population analyzed had the same age distribution[9] Population censuses and estimates have been obtained from the Brazilian Institute of Geography and Statistics (IBGE). To calculate the age-specific rates, we defined for this study as follows: ≤ 24, 25–34, 35–44, 45–54, 55–64, ≥ 65 years. Therefore, we were able to separately analyze the Brazilian Ministry of Health’s priority patient screening group of 25–64 years old.

To measure incidence and mortality changes, we have calculated the annual percentage change (APC), the average annual percentage change (AAPC) and their corresponding 95% confidence intervals (95% CI) using the Joinpoint Regression Program[10]. The model selection was performed by the Monte Carlo Permutation Test, which determines the p-value from the permutation distributions derived from F-statistic as a goodness-of-fit measure[11].

This research project was approved by the Research Ethics Committee of the Federal University of Sergipe and all methods were executed in accordance with the relevant guidelines and regulations. We have used patient anonymized databases and consequently obtaining informed consent was infeasible. For this, we have been given an exemption by the ethics committee, as specified in Resolution number 466, December 12th, 2012, of the Ministry of Health of Brazil.

Results

The Aracaju Cancer Registry recorded 1,060 cases of cervical cancer, 1,997 of carcinoma in situ and 354 associated deaths, from 1996 to 2015 (obtained from the Brazil Mortality Information System). Among the invasive neoplasms, 80% were squamous cell carcinomas, as shown in Fig 1.

Fig 1

Numbers and percentage of cases of cervical cancer by morphology.

Table 1 shows the annual number of cases, the age standardized rates of incidence and their respective confidence intervals. Overall, data are stable year to year.

Table 1

Annual age-standardized rates with confidence intervals; 1996–2015.

Incidence, invasive				Mortality			Incidence, in situ
Year	N(1,060)	ASR	95%CI	N(354)	ASR	95%CI	N(1,997)	ASR	95%CI
1996	59	32.3	24.1; 40.6	15	8.1	4.0; 12.3	40	1.19	12.1; 23.0
1997	66	36.1	27.4; 44.9	12	6.1	2.6; 9.5	44	17.6	12.4; 22.8
1998	53	28.2	20.6; 35.8	16	8.8	4.5; 13.1	58	23.0	17.1; 28.9
1999	59	30.0	22.4; 37.7	20	10.1	5.7; 14.5	50	20.1	14.5; 25.7
2000	55	24.1	17.7; 30.4	24	11.4	6.8; 16.0	47	17.4	12.4; 22.3
2001	75	34.5	26.0; 42.3	14	6.2	2.9; 9.4	75	27.7	21.4; 33.9
2002	75	33.0	25.5; 40.4	16	6.9	3.5; 10.2	91	33.0	26.2; 39.8
2003	64	29.5	22.2; 36.7	22	10.3	6.0; 14.6	49	17.3	12.4; 22.1
2004	54	24.3	17.8; 30.7	19	8.4	4.6; 12.1	123	43.3	35.6; 50.9
2005	57	23.6	17.5; 29.8	21	9.8	5.6; 14.1	152	51.5	43.3; 59.7
2006	58	24.5	18.2; 30.8	14	5.8	2.8; 8.9	163	55.1	46.7; 63.6
2007	37	12.9	8.7; 17.0	14	5.1	2.5; 7.8	121	37.4	30.7; 44.0
2008	30	9.6	6.2; 13.1	21	7.1	4.1; 10.1	126	36.8	30.4; 43.3
2009	33	10.3	6.8; 13.8	16	5.4	2.7; 8.0	95	27.6	22.0; 33.1
2010	47	14.5	10.4; 18.7	22	6.7	3.9; 9.5	153	40.2	33.8; 46.5
2011	50	15.1	10.9; 19.3	13	3.7	1.7; 5.7	116	30.7	25.1; 36.3
2012	52	15.8	11.5; 20.1	21	6.7	3.9; 9.6	114	29.6	24.1; 35.0
2013	47	12.8	9.1; 16.5	16	4.1	2.1; 6.2	120	29.1	23.9; 34.4
2014	54	14.1	10.3; 17.8	18	4.8	2.6; 7.1	135	32.7	27.1; 38.2
2015	35	9.1	6.1; 12.2	20	5.2	2.9; 7.3	125	30.2	24.9; 35.5

N: number of cases; ASR: age-standardized rate; 95%CI: 95% confidence interval.

When analyzing all ages combined, the ASR curve for invasive tumor incidence (Fig 2) presented a decreasing trend for incidence from 1996 to 2015. However, it fitted three joinpoints with non-significant trends: a decreasing trend from 1996 to 2008, a rising trend from 2008 to 2012, and a decreasing trend from 2012 on. The AAPC for incidence of invasive neoplasms over the whole period was −6.2 (95% CI: −7.9; −4.5). All individual age groups demonstrated decreasing incidence trends over time. However, mortality trends were statistically significant only in the 45–54-year-old age group. We separately analyzed the incidence of invasive lesions for the middle-aged adult group (45–64 years old), which included the most cases. Our analyses did not fit any joinpoints in the model and the APC was determined as −7.1 (95% CI: −9.2; −5.1).

Fig 2

Trends in age-standardized incidence and mortality rates for cervical cancer.

The age-standardized rate curves are shown (ASR) for all ages, with 3 joinpoints, demonstrating Annual Percent Change (APC) with no joinpoint, expressing Average Annual Percent Change (AAPC) (dark blue); carcinoma in situ incidence curve (lighter blue); and mortality curve (yellow).

For incidence of carcinomas in situ, we observed an upward trend in the ASR for all ages with AAPC of 13.3 (5.8; 21.3) until 2005, followed by a downward curve (Table 2, Fig 2), with AAPC of −4.8 (−8.5; −0.9). All age groups up to 64-year-olds presented similar curves to ASR for all ages, with one joinpoint, whereas the data for ≥65-year-olds were fitted with no joinpoints.

Table 2

Output of joinpoint analyses of carcinoma in situ incidence, invasive carcinoma incidence and mortality from cervical carcinoma data.

Joinpoints and APCs of ASRs with associated 95% CIs are shown, separated into age-specific groups.

		Incidence in situ		Incidence inv		Mortality
Age group	JP seg	APC (95% CI)	JP seg	APC (95% CI)	JP seg	APC (95% CI)
All	1996–2005	13.3* (5.8; 21.3)	1996–2005	-2.1 (-6.2;2.1)	1996–2015	-3.8* (-5.9; -1.7)
	2005–2015	-4.8* (-8.5; -0.9)	2005–2008	-27.8 (-57.8; 23.4)
			2008–2012	12.8 (-15.1; 49.8)
			2012–2015	-14.9 (-35.9; 13.1)
≤ 24	1996–2006	24.3* (12.8; 37.0)	NF	NF	NF	NF
	2006–2015	-6.8 (-13.2; 0.2)
25–34	1996–2005	14.5* (4.9; 25.0)	1996–2015	-6.8* (-9.5; -4.0)	1996–2015	-4.0 (-8.0; 0.1)
	2005–2015	-2.0 (-6.6; 2.9)
35–44	1996–2005	10.8* (3.5; 18.8)	1996–2015	-4.4* (-7.0; -1.6)	1996–2015	-2.1 (-6.1; 2.2)
	2005–2015	-6.3* (-10.5; -1.9)
45–54	1996–2006	9.7 (-0.5; 21.1)	1996–2015	-6.0* (-8.2; -3.7)	1996–2015	-4.2* (-7.6; 0.6)
	2005–2015	-7.5* (-12.9; -1.8)
55–64	1996–2015	-2.2 (-6.2; 2.0)	1996–2015	-7.6* (-10.6; -4.5)	1996–2015	-3.4 (-7.8; 1.3)
≥ 65	1996–2015	2.5 (-2.3; 7.5)	1996–2015	-5.4* (-8.5; -2.1)	1996–2015	-3.0 (-6.6; 0.8)

APC: annual percent change; ASR: age-standardized rate; CI: confidence interval; JP seg: time range segment; Incidence in situ: carcinoma in situ incidence; Incidence inv: invasive carcinoma incidence; NF: model not fitted.

*Significant APC; p ≤ 0.05.

Cervical cancer mortality decreased over time (Table 2, Fig 2) across all ages with an AAPC −3.8 (95% CI: −5.9; −1.7). Only the 45–54 age group showed a statistically significant decrease, with an APC of −4.2 (95% CI: −7.6; −0.6). Data from the other age groups show decreases in mortality over time, but these trends are statistically non-significant.

In this study, we found that the incidence rates (measured as ASRs) of invasive cervical cancer decreased until the year 2008, have shown a non-significant upward trend up to 2012 and thereafter a decreasing trend again. In some age groups this decrease in incidence has been maintained throughout the time series. Conversely, precursor lesions of cervical cancer showed increased incidence rates up to 2005, followed by a decrease. Fig 3 shows a comparison of the incidence of carcinoma in situ and invasive carcinoma, showing an average difference of 15 years between the peak ages of incidence.

Fig 3

Number of cases of carcinoma in situ and invasive carcinoma of the cervix, across age groups.

Discussion

Our findings suggest that the health policies implemented in Brazil to combat cervical cancer may be beneficial in reducing its instance and associated mortality. Our analysis shows an increasing incidence of precursor lesions up to 2005, which suggests improved early detection. However, public health managers should continue to optimize screening measures. Without this the detection of precursor lesions can decrease, as was observed in our study population, which could potentially lead to increased occurrence of invasive lesions. This might negatively affect cervical cancer mortality in the future. We cannot be certain whether our observed decrease in precursor lesion incidence was caused by incomplete catchment or true diminished incidence. Our observation of a reduction in incidence of cervical carcinoma in situ from 2005 and a rise in the incidence of invasive cervical neoplasms from 2008 suggests that changes in the screening policies, compliance, or in the cancer notification system have occurred. However, decreasing observed incidence data from 2012 on could be seen as evidence for decreased true incidence. To our knowledge, no solid evidence for such a decrease has been reported.

The importance of detecting precursor lesions is stressed by Moreno et al.[12] who assessed that 36% of cases of carcinoma in situ would progress to invasive if they remained without treatment. Monitoring outcomes after diagnosis of carcinoma in situ is unethical, given the risk of progression. As such, the rate of progression from in situ to invasive is always an estimation, with one study showing progression rates between 31% and 50% within 30 years[13]. In this study, the progression rate after appropriate treatment was just 0.7%, which is why treating carcinoma in situ is paramount.

In Brazil, the National Cancer Institute (INCA) has developed the National Cervical Cancer Control Program (PNCCC), which was implemented in 2001. This program aims to guarantee access to cervical examination, diagnosis and preventative treatment of precursor lesions for women of the prioritized age group (25–64 years old). In 2014, the Ministry of Health included the HPV vaccine in the National Vaccination Program. The vaccine is highly effective against HPV types 6, 11, 16 and 18[14]. HPV types 16 and 18 account for about 70% of cases of cervical cancer worldwide[15]. At the outset, the target population for vaccination was composed of girls aged 11–13 years. In subsequent years, the target age group has been expanded and boys included in the vaccine program[16]. It is hoped that the improvements in the screening strategy, together with HPV prophylaxis, will reduce cervical cancer mortality rates in the Brazilian population. Comparative trend studies will be needed to assess this.

Estimates of cervical cancer incidence for 2020 in Brazil[17] give ASRs of 12.6 and 10.1 / 100,000 in states and capitals, respectively. In the northeastern region of Brazil, which is less developed, ASRs are estimated at 16.1 and 10.1 / 100,000 in states and capitals, respectively. In this study, the incidence ASR for 2015 is lower than those estimated for Brazil. This could indicate a continued rising trend of incidence, which may be maintained if early detection strategies are not re-evaluated. Some authors mention that a decrease in cervical cancer incidence could occur mainly as a consequence of a decrease in the incidence of squamous cell carcinoma[18][19], which reflects improved control of HPV infection, which could be further improved with vaccination[20][21].

Screening policies are designed to decrease mortality[22][23] and a decrease in mortality throughout the time series in this study suggests that this has been successful. Sousa et al.[10] evaluated the mortality trend for cervical cancer in the state of Rio Grande do Norte, also located in the northeast of Brazil. They also observed a decreasing trend in ASR of 5.95 deaths/ 100,000 women per year in the period 2006–2010, and they predicted 3.67 deaths/ 100,000 women per year for the period 2026–2030. The ASR trend curves for invasive carcinoma incidence, which show an increasing trend in the last six years, and those of carcinoma in situ incidence, which show a decreasing trend in the last nine years of the series, can be compared with the mortality curves across the same period. From this, it seems possible that these shifting incidence patterns might lead to increased mortality in the future. Our study therefore should alert public managers that, if improvements in the screening process are not implemented, cervical cancer mortality could approach past levels.

The role of screening in decreasing cervical cancer mortality is well defined by Landy et al.[24], who predicted that mortality would be four times higher in women aged 35–49 years without screening, and also higher in the 50–64 age group. The opposite is predicted if screening were comprehensive; with mortality predicted to halve in women aged 35–49 years and decrease by even more in those aged 50–64 years. However, in Brazil, there has been a decrease in mortality in more developed regions and an increase in less developed ones[25]. This suggests differences in access to the means of prevention and treatment of precursor and invasive forms of cervical neoplasms.

Several studies have reported results similar to ours, indicating that cervical cancer screening has declined in recent years[26][27][28][29]. Control policies need to be re-evaluated to include new strategies such as the systematic incorporation of HPV vaccination[30], especially in less developed regions of the country. In the findings of Sreedevi et al. in India, the peak age of incidence is from 55 to 59 years[31], which indicates that this age group should be specifically targeted to improve screening strategies and participation. However, all age groups in this study presented decreasing trends in incidence of cervical cancers.

Oke et al.[32] found that cervical cancer incidence in the UK population has increased by more than 150% since 1980. Conversely, mortality has decreased by 69% in the same period, and continues to decline. Interestingly, they verified that diagnosis of cervical carcinoma in situ accounted for all this incidence increase, while rates of invasive cervical neoplasms have almost halved since 1980. Oke et al. suggested that efficient and comprehensive screening programs are more likely to detect indolent disease in the asymptomatic population. The population in our study has greater difficulty in accessing prevention programs and treatment in the public health network and we have found a different scenario. In Brazil, the incidence of in situ cervical lesions has been decreasing since 2006, while that of invasive neoplasms increased from 2006 to 2012 and decreased thereafter, although mortality has still decreased.

We have identified two limitations in this study. First, because of regional differences in screening strategies and in access to health services the results of the present study cannot be completely extrapolated to the other areas Brazil. Second, mortality rates are influenced by the quality of death certificate completion and the presence of a high percentage of undetermined causes of death in this dataset is likely to have affected mortality rates and trends. Recently, however, undetermined causes of death have dropped to acceptable levels.

Conclusions

In summary, we have found that incidence rates and mortality for cervical cancer have decreased in the years since screening strategies have been in operation, in the population of study. the recent trends showing a decreasing incidence of cervical precursor lesions may indicate either that their incidence has diminished or that the detection incidence has diminished without a change in underlying lesion occurrence. If the latter is true, invasive tumor incidence rates could return to higher levels, which is likely to impact the future mortality associated with cervical cancer. In this case, Brazilian health policies should be re-considered and include strategies to screen every woman in a defined age group and to assess and improve the rates of HPV vaccination.

(XLSX)

Click here for additional data file.

1 Oct 2019

PONE-D-19-19030

Trends in cervical cancer and its precursor forms to evaluate screening policies in a mid-sized Northeastern Brazilian city

PLOS ONE

Dear Dr. Lima,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The reviewers raised several concerns that must be addressed for the paper to be publishable. I would like to stress that it is a major revision and I have some doubts that you will be able to address those concerns. My main concern is the first point of the second reviewer. It is also important to provide details of the cancer registry used in the study and describe where the data can be found. Finally, I am also troubled by the lack of specifics on the methods used in the study and its appropriateness for the study.

We would appreciate receiving your revised manuscript by Nov 15 2019 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Gabriel A. Picone

Academic Editor

PLOS ONE

Journal Requirements:

1. When submitting your revision, we need you to address these additional requirements.

Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

http://www.journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and http://www.journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: No

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: No

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is a potentially interesting manuscript, if limited in its generalizability due to the specifics of its chosen study population. However, it is in dire need of editing for content and comprehensibility by someone skilled in writing in the English language. As it stands now, the paper is a chore to read and difficult to understand. The comments below are based on my best guess as to what the authors are trying to convey.

Specific comments:

Introduction; last paragraph. Please be clear on what the objective of the study is in as laconic a manner as possible. Do the authors hypothesize that improved (changes) screening rates (in years X,Y,Z) lead to the cancer being identified at earlier stages? That HPV vaccination will lead to reduced incidence rates? Something else?

Lines 70-79. Please be more clear and straightforward: preinvasive lesions are defined as X; invasive as Y; Z is excluded.

Line 81. How did you revise these? Why does it matter if you then exclude?

Lines 82-90. Be very specific in explaining how you calculated age-adjusted rates. What was the standardized population on which you performed the adjustment? You may use a citation for the formula, but not the important details of something central to the paper.

Lines 90-101. Provide more detail on the methods chosen for the study. Less detail on administrative proceedings.

General Comments.

The HDI is mentioned in numerous places in the text, yet its presence is primarily a red herring as it is never used in the analysis. Please avoid providing information that does not contribute to the study. Similarly, I am sure Aracaju is a wunderbar place, but what does its longitude and latitude have to do with cancer?

Provide details on the cancer registry, specifically were any changes made to the way the data was collected (including levels of detail relevant to identifying the study conditions) over the time period included in the study?

Lack of detail on how this cancer registry works brings up the following questions: in situ will progress to invasive cancer at a certain rate. How is this handled by the authors and/or recorded by the registry? in situ patients can also die for numerous reasons, why was mortality among this strata not considered? In general more detail on sample selection is needed... We started with X people, excluded Y people for reasons, final sample sizes were z1 for this an z2 for that category etc.

Is mortality cause-specific (e.g. cause of death documented) or incidence-based (e.g. all mortality after onset).

Table 2 is hard to read; suggest authors move CI below the APC.

An total/combined trend is useful for comparison.

Figures need to be in higher resolution with captions provided for each.

Reviewer #2: Dear authors,

Thanks for the opportunity to review your study. My comments intend to improve your work.

Major comments

1. The research question is to estimate the impact of screening on incidence and mortality from invasive cervical cancer lesions, but there´s no data on screening. I wonder if it is correct to properly determine a causal association in this analysis. The study design seems not appropriate to answer the research question. The conclusion is overestimated.

2. Authors used the ICD D06 for precursor lesion. Is well known that for precursor lesions the ICD N87 should also be evaluated. The figures may be over or underestimated. I wonder that it is not possible to draw a conclusion based on this.

3. It is necessary to clarify more how the ICD C55 was “revised and excluded”. As you are using an extended period for the analysis, it might have influenced the figures. I suggest reading the paper “Disparities in time trends of cervical cancer mortality rates in Brazil. Vale DB et al., Cancer Causes Control. 2016”.

4. Please specify more clearly which world population was used for adjustment (and also include in the tables this information): 1960? 2000? 2010? The reference 7 is a citation, please use an original one. Please clarify why did you choose to use the world population instead of the Brazilian one.

5. The main problem in the trend test used is that the figures are too small, which is expected for a rare condition as cancer… There is a lot of variation among years of the absolute numbers. For example, the number of D06 varies significantly among years… The statistical analysis seems a very superficial way to look at the real figures.

6. There is a conceptual error in the discussion. It is expected that after some years of implementation of a screening program, the precursor lesions rates would decrease, as the prevalent cases will be excluded by treatment. Authors should be more careful with the interpretation of this results.

7. Did you notice that the figures for incidence were very different in 2008 and 2009? What might have happened? Because this difference is crucial to determine the JointPoint analysis presented and, as the absolute figures are too small, I wonder if it is appropriate to use a Joint analysis in this case. I think only the entire period tendency analysis would be adequate.

8. Figures are too small for analysis by age-groups. It is not consistent.

9. In the discussion, authors should include some data on screening in the region during the period.

10. Authors use just a few national/regional references to discuss their results. I think it is important to use more local data to validate the study.

11. Discussion is long and unfocused.

13. Reference 6 – please use the more updated guideline (2016).

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Diama Bhadra Vale

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

27 Mar 2020

Reviewer #1

I have added a new year of data and recalculated trends

- I have submitted to English language edition

- Introduction. I tried to respond to the reviewer’s queries

- Line 70-79. Corrected

- Line 81. The head of the cancer registry and senior author (a surgical oncologist) CAL went back to records and pathology reports to resolve any conflicting registration. That was done to certify all cases were included.

- Line 82-90. Ok, more details were added on how age-specific rates were calculated

- Line 90-101. Ok, I hope I have provided the required information

General comments:

- About HDI and coordinates. Accepted

- Details on the cancer registry. Data collection was modified to include laboratory databases more recently, instead of calling on laboratories to gather data; but not the consistency of case catchment. The cancer registry data has been submitted and approved for Cancer Incidence in 5 continents X and XI, and Concord-2 and -3.

- About in situ. Cases are registered as in situ if no other diagnoses were identified as invasive in less than one year; otherwise, both in situ and invasive were registered. For the present paper, I decided not to consider assess mortality for carcinoma in situ because the impact on mortality would be minimal and, if present, would be mostly due to other causes.

- We assessed al cause mortality from the official Mortality Information System

- Table 2 was modified

- Figures in high resolution were provided

Reviewer #2

1. Actually I tried to estimate the impact of screening on incidence and subsequently on mortality; however, data on screening, other that of SISCOLO, is not available, which is included in the registry database

2. ICD N87 is not reported. Some pathologists use the term high grade/severe dysplasia interchangeably with carcinoma in situ. High grade dysplasia is only reported as carcinoma in situ when the pathologist considers them to be the same – it is documented as carcinoma in situ

3. ICD C55 was revised to make sure topography and histology was not related to the uterine cervix. In case, they were from other parts of the uterus, they were excluded from analysis

4. More detail on calculation of age standardized data was included – the standardization by the direct method was used (Segi, 1960) which defines the number of individuals by 5-year age groups to a total of 100,000. We preferred not to use the Brazilian population because if so comparisons would be only in Brazil and the world population is thoroughly used.

5. I agree that figures are small but trend analysis using the Joinpoint Regression Program is validated worldwide

6. I tried to overcome that

7. Yes, probably due to under catchment of cases, and that possibly made the following year present a higher number of cases

8. Ok, that’s the way it is

9. Unluckily, we have on screening was collected by SISCOLO, which is one of our data sources

10. I have tried but local data is scarce

11. I have reorganized discussion

12. Ok

- I have added an additional year of data and recalculated trends

10 Apr 2020

PONE-D-19-19030R1

Trends in cervical cancer and its precursor forms to evaluate screening policies in a mid-sized Northeastern Brazilian city

PLOS ONE

Dear Dr. Lima,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

I agree with the reviewers that the paper is much improved. One of the reviewers is ready to accept the paper, while the other has minor comments. These comments are easy to address, and I hope that you can respond to them right away so I can accept the paper.

We would appreciate receiving your revised manuscript by May 25 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Gabriel A. Picone

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript is much improved.

1. Do not use blue/light blue in figure 3 - hard to tell the difference. Choose a different color.

2. What is meant by "Brazilian health policies need to be re-evaluated"? Be explicit. As is, this advice is very vague.

3. Report the smallest number of cases across the age groups used. Age-adjusting using the world's population gives questionable results when the case numbers in an age group are exceptionally small (should not be an issue, but best to verify, a response in the rebuttal letter is enough - no need to put in text).

4. What is the probability of in situ progressing to invasive tumor? If small the conclusion would be weakened.

5. A second run of English editing is needed. I has improved greatly from the first draft, but still.

Reviewer #2: Dear authors,

You have addressed the issues and improved the manuscript substantially.

Congratulations.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Diama Bhadra Vale

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

21 Apr 2020

Reviewer #1

1. I believe that remark was for figure 2.

Joinpoint Regression Program won’t allow to change line colors. My preference was to keep the graphic generated by the program. To overcome the difficulty mentioned, I increased the line width. I hope that will do.

2. I included some words, trying to be explicit on that. That can be seen in the marked-up copy.

3. For the sake of synthesis, the authors decided not to report number of cases across age groups, which can be found in the supplementary material file. We believed that was nor important, but actually, we calculated age-specific rates instead.

4. I included some words trying to respond to that remark. That can be seen in the marked-up copy.

5. We submitted the manuscript to Edanz Group for a second run of English editing.

Reviewer #2:

No additional revision was required.

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

5 May 2020

Trends in cervical cancer and its precursor forms to evaluate screening policies in a mid-sized Northeastern Brazilian city

PONE-D-19-19030R2

Dear Dr. Lima,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

With kind regards,

Gabriel A. Picone

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

8 May 2020

PONE-D-19-19030R2

Trends in cervical cancer and its precursor forms to evaluate screening policies in a mid-sized Northeastern Brazilian city

Dear Dr. Lima:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

For any other questions or concerns, please email plosone@plos.org.

Thank you for submitting your work to PLOS ONE.

With kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Gabriel A. Picone

Academic Editor

PLOS ONE