Evaluation of the Impact of Service Screening: The Florence City Programme (1990–1996)

Abstract

In Europe, the challenge today is the evaluation of the impact of mammography service screening. Here, we analyze data of the Florence City Breast Cancer Screening Programme from 1990 to 1996. Breast cancer cases registered in women aged 50 to 69 were partitioned by diagnostic modality and screening invitation. The cumulative number of breast cancer deaths within cases was calculated to estimate the rates of cancers proving fatal within a period of 8 years of observation (incidence-based mortality). For women who were not yet invited at the time of diagnosis, there was a 41% significant mortality reduction (RR = 0.59, 95% CI: 0.42-0.82) when compared with the data in 1985 to 1986. In those invited, there was a significant 55% mortality reduction (RR = 0.45, 95% CI: 0.32-0.61). Percentages of breast conserving surgery by screening modality were higher in cases occurring in invited women and are considered an important outcome of service screening. This study is one of the first examples of the evaluation of service screening and supports the conclusion that screening is contributing to the reduction of mortality from breast cancer.