Objective. To conduct a comparative analysis of the effectiveness of treatment in terms of five-year overall, disease-free and cancer-specific survival rates of operable patients with five intrinsic molecular-biological breast cancer subtypes (T1-4N2-3M0). To establish the subtype that requires a less aggressive adjuvant systemic treatment.

Materials and methods. The five-year results of treatment of 246 patients suffering from luminal A, luminal B-like (Her2/neu-negative), luminal B-like (Her2/neu-positive), Her2/neu-positive (non-luminal) or triple-negative breast cancer, radical treatment having been treated at N.N. Alexandrov National Cancer Centre of Belarus in 2006-2009 were studied by the Cancer Registry data, medical records and histories.

Results. There was a statistically significant benefit in the survival rate among the patients with the breast cancer luminal A subtype compared to the triple-negative cancer: a five-year overall survival was 78.4±4.2% and 53.8±6.9% (p=0.048), a cancer-specific survival was 81.3±4.0% and 57.5±7.0% (p=0,017), respectively. The outcome obtained evidenced about a necessity to practice a less aggressive treatment for the luminal A subtype of cancer.

Conclusion. Among all the molecular-biological subtypes, the luminal A breast cancer is the most favorable in terms of five-year overall and cancer-specific survival.