TRENDS IN THE PREVALENCE OF CERVICAL INTRAEPITHELIAL NEOPLASIA GRADE-3 IN THE DISTRICT OF FLORENCE, ITALY

Aims and background The objective of this study was to investigate the detection rate of cervical intraepithelial neoplasia grade III (CIN 3 ) in previously unscreened women, in order to reveal trends over time in the prevalence of CIN 3 in the District of Florence, where a popula tion-based screening for cervical cancer has been going on since 1973, Study design: We considered the women, recorded in the computerized a rchives of CSPO, who had had no pap test for at least 10 years. Trends of CIN 3 (histologically proven) were analyzed within age groups; the effect of age, cohort and period were considered by means of a Poisso n regression model. Results: A total of 648 cases of histologically pr oven CIN 3 were detected in the study period. The detection rates of C IN 3 increased steadly within age groups over birth cohort and calenda r period simultaneously. The Poisson regression analysis showed that o nly the model with age + time trend was statistically significant. Con clusions: Although several biases should be taken into account, the an alysis seemed to indicate a real increase in CIN 3 prevalence. An incr ease in frequency of precancerous lesions for cervical cancer in more recent birth cohorts supports the need to keep screening coverage and efficiency as high as possible.