Risk of cancer death by comorbidity severity and use of adjuvant chemotherapy among women with locoregional breast cancer

Findings suggest that, compared to women with no comorbidity, patients with breast cancer age 70 and older with severe comorbidity are at increased risk of dying from breast cancer, even after adjustment for adjuvant chemotherapy and other tumor and treatment differences. This information adds to risk-benefit discussions and emphasizes the need for further study of the role for adjuvant chemotherapy in these patient groups.