Kaeli K Samson1, Gleb Haynatzki1, Amr S Soliman1, Zdravka Valerianova2. 1. College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA. 2. Bulgarian National Cancer Registry, National Oncological Hospital, Sofia, Bulgaria. Electronic address: zvalerianova@sbaloncology.bg.
Abstract
INTRODUCTION: In most developed countries, incidence of cervical cancer declined likely due to well-established cervical cancer screening programs. However, such decline has not been identified in Eastern Europe, where such programs are not well established. METHODS: This study utilized data of the Bulgarian Cancer Registry for the period 1993-2013. Age-standardized incidence and mortality trends were analyzed using Joinpoint regression. Maps were created to illustrate spatial distributions of rates. RESULTS: The northern region of Bulgaria showed a larger cervical cancer burden than the southern region and rural women tended to be diagnosed at older ages (p<0.0001) and later stages (p<0.0001) than urban women. The distribution of disease stages changed over the 21 years, with most common stages of diagnosis being stage II in 1993 (39.2%) to stage I in 2013 (44.7%; p<0.0001). While age-standardized mortality slightly increased over the 21 years (from 4.8 to 5.2 per 100,000; p=0.009), age-standardized incidence increased from 14.0 to 21.4 per 100,000 up until 2006 (p<0.001), after which it plateaued. CONCLUSIONS: The lack of a similar plateau in mortality may be because the second most prevalent stage of diagnosis in recent years was stage III, indicating diagnosis at advanced symptomatic stages. Cervical cancer incidence is expected to continue to decrease if screening programs are strengthened and human papillomavirus vaccines are widely utilized. As Bulgaria has shared cervical cancer trends with other Eastern European countries in the past, it may be beneficial to develop future prevention interventions based on a regional, rather than a country-specific level.
INTRODUCTION: In most developed countries, incidence of cervical cancer declined likely due to well-established cervical cancer screening programs. However, such decline has not been identified in Eastern Europe, where such programs are not well established. METHODS: This study utilized data of the Bulgarian Cancer Registry for the period 1993-2013. Age-standardized incidence and mortality trends were analyzed using Joinpoint regression. Maps were created to illustrate spatial distributions of rates. RESULTS: The northern region of Bulgaria showed a larger cervical cancer burden than the southern region and rural women tended to be diagnosed at older ages (p<0.0001) and later stages (p<0.0001) than urban women. The distribution of disease stages changed over the 21 years, with most common stages of diagnosis being stage II in 1993 (39.2%) to stage I in 2013 (44.7%; p<0.0001). While age-standardized mortality slightly increased over the 21 years (from 4.8 to 5.2 per 100,000; p=0.009), age-standardized incidence increased from 14.0 to 21.4 per 100,000 up until 2006 (p<0.001), after which it plateaued. CONCLUSIONS: The lack of a similar plateau in mortality may be because the second most prevalent stage of diagnosis in recent years was stage III, indicating diagnosis at advanced symptomatic stages. Cervical cancer incidence is expected to continue to decrease if screening programs are strengthened and human papillomavirus vaccines are widely utilized. As Bulgaria has shared cervical cancer trends with other Eastern European countries in the past, it may be beneficial to develop future prevention interventions based on a regional, rather than a country-specific level.