Hartung C, Porsch M, Stückrath K, et al. - The clinical relevance of molecular subtyping of triple-negative breast cancer [TNBC; the most aggressive type of breast cancer (BC)] in improving the individual indication of systemic therapy has been investigated.

• From a prospective, multicenter cohort including 1,270 histopathologically confirmed invasive, non-metastatic BCs, researchers obtained 124 (82%) of 152 TNBC tumors and performed molecular subtyping on them.

• PAM50 analysis led to identification of 87% of the tumors as basal with an inferior clinical outcome compared with patients with nonbasal tumors.

• Twenty-three (15%) of TNBCs were identified as luminal androgen receptor (LAR) subtype using the TNBCtype-6 classifier.

• Patients with LAR subtype can be identified via performing molecular analysis and subtyping of TNBC.

• Given the less sensitivity of patients with LAR subtype to conventional chemotherapy, exploration of new treatment options, including androgen receptor-blocking agents and immune checkpoint inhibitors, is stressed.