A long-term follow-up of breast cancer cases finds that even women with a tumor subtype thought to carry the best prognosis — luminal A — show steady declines in survival after 10 years. The study appears in Cancer Epidemiology, Biomarkers & Prevention.
Researchers followed some 900 women from a community-based managed care system whose invasive tumors were classified according to molecular subtypes: luminal A, luminal B, basal-like, and HER2-enriched. Median follow-up was 13 years; some patients were followed for over 20 years.
Compared with luminal A tumors, luminal B and HER2-enriched tumors carried a twofold higher risk for breast cancer mortality. However, the authors observe: “Despite its markedly higher survival probabilities in earlier years of follow-up, luminal A subtype was the only subtype that continued a steady drop in survival over the 20-year period with little leveling off in later years.”