Evaluation of 1,030,482 Cervical Smear Results in Brazilian Population

BACKGROUND: The objective was to determine the prevalence of abnormal cytologic smears in a large population of a Brazilian city. METHODS: Retrospective study of cervical cytology results performed at a private laboratory in São Paulo - Brazil. A total of 1,030,482 cytology tests were performed between January 2010 and December 2015. RESULTS: Among the satisfactory cytologies, we observed abnormal results in 8.9% (91,371). Analyzing the proportion of exams with altered results over the years, there was no change in these rates. We observed that the proportion of abnormal exams decreased with increasing age. Atypical squamous cells of undetermined significance, possibly non-neoplastic (ASC-US) cytology was the most common abnormality found in the general population with 73.19%, followed by low-grade intraepithelial lesion (LSIL) with 20.5%; these 2 cytological abnormalities add up to 93.69 % of all abnormal results. There was an increase in ASC-US with advancing age, a decrease in prevalence of LSIL, especially after the age of 30 and high-grade intraepithelial lesion (HSIL) shows two peaks of elevation, respectively in the age groups of 30-39 years and over 70 years. CONCLUSION: Women under the age of 30 showed a higher prevalence of cytological abnormalities, however most of these changes are low-grade lesions. In older women, cytological abnormalities are largely high-grade lesions, requiring greater care to prevent progression to cancer.