Background: Few population-based studies have reported jointly analyses of relative survival according to the following prognostic factors: tumour-node-metastasis (TNM) stage, age, number of examined and positive nodes, hormonal status, histological Scarff, Bloom and Richardson (SBR) grade, tumour extension, hormone receptor status and tumour multifocal status.
Patients and methods: Data on female invasive breast cancer were provided by the Cote d'Or breast cancer registry. The Kaplan-Meier method and log-rank test were used to estimate and compare the survival probability at 1, 5, 10 and 15 years. The effect of prognostic factors on survival was assessed with crude and relative multivariate survival analyses.
Results: Crude survival seemed to be worse in patients aged >60 years compared with those aged 45-60 (P > 0.0001), whereas relative survival did not differ. TNM stage, histological SBR grade, progesterone receptor status, tumour multifocal status, locoregional extension and the period of diagnosis were independent prognostic factors of crude and relative survival.
Conclusion: Breast cancer is influenced by many factors. Despite the absence of any association between the number of examined nodes and overall survival in this study, the number of nodes removed, in conjunction with other prognostic factors, may be useful in selecting node-negative patients for systemic therapy.