Molecular subtypes are prognostic for N3 breast cancer patients in the modern therapeutic era.

Nodal (N) status and molecular subtypes are well-known prognostic factors for breast cancer patients. The aim of the present study was to evaluate whether there was a prognostic role of molecular subtypes for pN3a breast cancer patients in the modern therapeutic era. The present study retrospectively evaluated a total of 521 breast cancer patients who had 10 or more metastatic lymph nodes and received adjuvant systemic therapy at the Oncology Department of four different centers in Turkey between 2000-2015. Patients were divided into four molecular subtypes by immunohistochemical staining. There were no significant differences in relapse rates according to the molecular subtypes (P=0.07). The five year disease free survival rate was 62% for the whole study population, 67% for Luminal A tumors, 53% for Luminal B tumors, 64% for human epidermal growth factor receptor 2-positive tumors and 56% for triple negative tumors. Luminal A patients had a better progression free survival when compared with Luminal B (P=0.026) and triple negative (P=0.07) patients. pT stage (P<0.001), and breast cancer subtype (P<0.001), remained significant independent factors for disease free survival. Therefore, breast cancer subtypes are still prognostic for patients with pN3 breast cancer.