Multifocality as a prognostic factor in breast cancer patients registered in Danish Breast Cancer Cooperative Group (DBCG) 1996–2001

The purpose of this study was to investigate the prognostic influence of multifocality in breast cancer patients. In a cohort of 7196 patients there were 945 patients with multifocality. We found no prognostic influence of multifocality on overall survival when controlling for known prognostic factors. We found a small but significant influence on disease-free survival (HR = 1.16 [1.03–1.31]) and a strong correlation between multifocality and known prognostic factors. This was in accordance with an earlier study done on a smaller population and in a different period of time [Pedersen L, Gunnarsdottir KA, Rasmussen BB, Moeller S, Lanng C. The prognostic influence of multifocality in breast cancer patients. Breast 2004;13:188–193].