In breast cancer, are treatments and survival the same whatever a patient's age? A population-based study over the period 1998-2009.

Aim: The present study aimed to describe treatments, relative survival and prognostic factors in breast cancer patients according to age.

Methods: All women with primary invasive breast cancer, diagnosed from 1998 to 2009 in the department of Côte d'Or, were retrospectively selected. Variations in treatments administered according to age (<50 years, 50-74 years, >74 years) and period were assessed using Cochran-Armitage trend tests and χ(2) -tests, respectively. Prognostic factors according to age were estimated using a generalized linear model with a Poisson error structure.

Results: Overall, 4305 women were included. The oldest women (aged >74 years) were more likely than the youngest women to have comorbidities, advanced stage tumors, hormone receptor-positive tumors and be human epidermal growth factor receptor 2-negative. The use of breast conserving surgery plus adjuvant therapy decreased in older women (>74 years), whereas the proportions of women without treatments and with adjuvant hormone therapy increased with age. Multivariate relative survival analyses according to age showed an increased risk of death in women aged 50-74 years and >74 years with comorbidities compared with those without comorbidities; relative excess risks were 1.85 (1.13-3.02) and 3.23 (1.26-8.31), respectively. In contrast, a decreased risk of death was observed in women aged 50-74 years diagnosed by medical imaging compared with those diagnosed by clinical signs; relative excess risks 0.44 (0.22-0.89).

Conclusion: Elderly women compared with the youngest women were diagnosed with more favorable tumor biology (hormone receptor-positive tumors, human epidermal growth factor receptor 2-negative). However, survival was poor in elderly women who had comorbid conditions, did not attend screening mammography examinations and were undertreated.