Plastic spatula with narrow long tip provides higher satisfactory smears for Pap test.

BACKGROUND: Ayre spatula for cervical smear collection is being used despite the suggestion that different modified spatulas provide more satisfactory sampling. AIMS: To see whether the cytological pickup improves with the use of long tipped spatula. SETTING AND
DESIGN: Rurally based University Hospital; crossover study.
MATERIALS AND METHODS: Pap smear using Ayre spatula in 500 and with plastic narrow long tip (Szalay) spatula in 500 clinic attending women was taken and analyzed. Crossover smears were taken with modified spatula in 163 and using Ayre spatula in 187 women after 2 weeks of initial smears. The same pathologist made cytological reporting for all smears and was unaware of the type of spatula used.
RESULTS: Smears from Ayre spatula had significantly higher reports of inadequate smears (94 of 500 vs. 68 of 500 for Ayre and Szalay, respectively; P = 0.032) and it remained so even after crossover (94 of 187 vs. 70 of 163 for Ayre and Szalay, respectively; P = 0.2). Cellular quality appeared better with smears taken using Szalay spatula, but the overall abnormal smear detection rate remained similar with either collection tool (χ(2) = 1.5; P = 0.2).
CONCLUSIONS: Proportion of satisfactory smears is higher when long tip plastic spatula is used for collection of sample.

Introduction

Cancer of the uterine cervix continues to be a leading cause of morbidity and mortality among women world-wide. Of the new cases reported, three fourth of them occur in developing countries. It is the most common neoplasm among Indian women accounting for 20-50% of all cancers and 80-85% of female genital cancers.[1] Although, adoption of the screening program with exfoliative cytology has resulted in a large decline in incidence of cervical cancer and mortality due to it in developed countries, it remains a significant problem in developing countries either because of ineffective or no screening.[2]

Approximately, two-thirds of the false negative results are caused by sampling error, and the rest are caused by detection errors. An attempt was made to see whether the cytological pickup improves with the use of long tipped spatula.

Materials and Methods

Clinic attending 1000 women aged between 30 years and 70 years and consenting to participate in the study were recruited. Celibate women, those having vaginal bleeding or lesion on the cervix were not included for the study.

Cervical smear for Pap test was obtained using the traditional wooden Ayre's spatula in 500 cases and with Szalay spatula in 500 cases. Szalay spatula is made of plastic and has an elongated narrow tip [Figure 1]. Re-screening was planned in 2-3 weeks for crossover. From Ayre spatula group, 163 women returned and had repeat smear from Szalay spatula; and 187 women of initial Szalay spatula group had repeat smear using the Ayre spatula.

Figure 1

Smear collecting devices. Ayre = Traditional wooden spatula, Szalay = Long tipped plastic spatula

Specimen for cytology were obtained using either of the spatula being rotated firmly over ectocervix after inserting longer tip in to the external cervical os at inspection using a non-lubricated speculum. The material on the slide was spread thinly and immediately fixed by flooding with 95% ethyl alcohol. A single person (1st author) obtained all the smears, and a single person who was not aware of the type of spatula used evaluated the slides for adequacy parameters and cytopathology.

The smears were considered as adequate for evaluation if endocervical cells and transformation zone (TZ) components were present in the smear. Presence of intraepithelial lesions was considered as abnormal smear. The slides were interpreted and reported as per the Bethedsa system.[3]

Study had the approval of local Ethics and Scientific Committee.

Results

Reporting of inadequate smears was high with those taken by Ayre spatula (initial smear: Ayre 94/500 and Szalay 68/500; χ2 = 4.6; P = 0.032; df = 1; 95% CI = 0.02-0.12). It appeared similarly high even after the crossover (Ayre 94/187 and Szalay 70/163; χ2 = 1.5; P = 0.2; df = 1; 95% CI = −0.03-0.17), but the difference was not significant. Cellular quality appeared better with smears taken using Szalay's spatula, but the overall abnormal smear detection rate remained similar with either method [Table 1].

Table 1

Cytological result in relation to the type of spatula used to collect cervical smear

Plastic made Szalay spatula with its smooth surfaces resulted in significantly less contact bleeding (99 of 500 with Szalay vs. 154 of 500 with Ayre spatula; χ2 = 9.7; P = 0.0018; df = 1; 95% CI = 0.12-0.26) after a procedure.

There were a total of 17 abnormal Pap tests (1.7%) and the detection rates were similar depending on the type of collecting device (1.8 and 1.6% for Ayre and Szalay devices, respectively; χ2 = 0.06, P = 0.80). The repeat smears with the same collective device had apparently higher abnormality detection rate for Ayre (3.7 and 1.8%; χ2 = 2.26, P = 0.13) as well as when Szalay was used (3.7 and 1.6%; χ2 = 2.57, P = 0.10) although the difference was not significant.

Visual inspection of the cervix after 1 min of application of 4% acetic acid for visual inspection with acetic acid (VIA) was carried out in all the 1000 cases while obtaining initial smear. There were 22 cases (2.2%) with dense aceto-white areas, which were graded as VIA positive.

Cervical biopsies were taken from 32 cases that included 15 cervices, which were VIA positive. None of these VIA positive cases showed any cytological abnormality.

Histopathological examination reported cervical intraepithelial neoplasia in 10, squamous metaplasia in 3, and chronic cervicitis in 6 cases. In addition, micro-invasive carcinoma of the cervix in 3 and endocervical adenocarcinoma in 1 case was detected. The Pap test picked up all these 4 cases.

Discussion

The presence of cells from endocervix and TZ, the site where premalignant change arises in the uterine cervix can be logically considered to be reflective of adequacy of the smear. Hence, their presence or absence was given weightage in reporting smear in Bethesda system.[3] Meta-analyses have shown that compared with other collection devices, the Ayre spatula is an ineffective device for collecting endocervical cells.[4]

There have been concerns expressed about the inclusion of endocervical component to define adequacy of the smear.[5] The present cross-over study to evaluate the efficacy of long tipped plastic spatula in comparison with traditional wooden Ayre spatula for collection of cervical smear found that the former yielded significantly higher adequate smears for evaluation.

The presence of red blood cells may obscure study of squamous cells in the smear rendering it unsatisfactory. It has been demonstrated that coexisting red blood cells compete with squamous cells to be retrieved on the filter that transfer the cells to the slides.[6] However, there is very limited data on this aspect.

Use of wooden spatula for collection of smear may abrade the surface because of inherent roughness when compared to plastic spatula. The present study showed that the incidence of contact bleeding due to the procedure was significantly less (P = 0.001) when a smooth surfaced plastic Szalay spatula was used.

The report that atypia was more likely to be present in limited smears than satisfactory smears[7] should not be the argument used to defend inadequacy of smears.

The present study by virtue of single gynecologist taking all the smears and a single cytopathologist screening the reports removes the bias due to technique and observer variations from the interpretation. Population based study would have been better, but the constraints of manpower and other logistics limited the study to hospital visiting women. The intention to have the same woman as case and control apparently failed since the loss of sample size was significantly high for the return visit for cross-over component of the study.

The picking of a higher proportion of abnormal smears at the repeat screen at cross-over did attract the attention. We are not able to provide tangible explanation for this difference, although, it was not statistically significant. The patient, person collecting the smear and the cytologist were the same for both components of the study. Similarly, inability to document cytological abnormality in proportion of VIA positive cases despite pathological abnormality requires further scrutiny. If the designs of cervical smear collection devices adversely affects adequacy of smears, this factor may reduce not only the effectiveness of screening, but also cost effectiveness because of need for repeat smears. Extended tip spatulas have the theoretical advantage of more effective cell sampling from the TZ. It has been shown that Ayre spatula is ineffective device for collecting endocervical cells and yield of dyskaryotic cells than the extended tip spatulas.[8] The present study also provided similar results suggesting better cellular quality of smears with those taken by long tipped Szalay plastic spatula.

Although, it was not a randomized study, and it was based on opportunistic screening of clinic attending women, we feel that the extended tip plastic spatulas should replace Ayre spatula in routine screening programs for cancer cervix to obtain satisfactory smears.