Second breast cancers in a Tuscan case series: characteristics, prognosis, and predictors of survival

Little is known about long-term outcomes following a second breast cancer diagnosis. We describe the epidemiology, characteristics and prognosis of second breast cancers in an Italian cohort. We identified women with two breast cancer diagnoses from 24 278 histology records at a Tuscan breast cancer service between 1980 and 2005, and determined their survival status. Disease-specific survival from second diagnosis was examined using Cox regression analyses. Second cancers were identified in 1044 women with a median age of 60 years. In all 455 were ipsilateral relapses and 589 were contralateral cancers. Median time between first and second diagnosis was 63.4 months. The majority of second cancers was small invasive or in situ tumours. Estimated 10-year survival from a second cancer diagnosis was 78%. Survival was poorest when the second cancer was large (HR = 2.26) or node-positive (HR = 3.43), when the time between the two diagnoses was < 5 years ( HR = 1.45), or when the diagnosis was in an earlier epoch (HR = 2.20). Second tumours were more likely to be large or node-positive if the first breast cancer had these features. Prognosis following a second breast cancer in this cohort was generally good. However, large or node-positive second tumours, and shorter intervals between diagnoses were indicators of poorer survival.