Problems to affect long-term survival for breast cancer patients: An observational study of subsequent lung/bronchus malignancies

The overall survival of breast cancer (BC) patients increased significantly for decades; however, their long-term survival was seriously impaired by subsequent malignancies. This study aimed to investigate the risk factors of subsequent lung / bronchus primary malignancies among BC survivors. A total of 535,941 BC female survivors diagnosed were identified by using SEER(∗)Stat database in 1973 to 2014. Among them, 9398 had subsequent lung/bronchus malignancies. Clinico-pathological risk factors were evaluated for the development of subsequent lung/bronchus cancer. The main measures were the incidence and risk factors of subsequent lung/bronchus primaries. Logistic regression analysis and survival analysis were performed. Overall, among 535,941 BC survivors, 73,394 (13.69%) patients with subsequent primaries were identified from 1973 to 2014. The overall medium second tumor-free time was 72 months. Estrogen receptor (ER)-positive, progesterone receptor (PR)-positive, human epidermal growth factor receptor-2 (HER2)-positive, radiotherapy, and surgery treatment were protective factors against overall subsequent malignancies, whereas HER2/hormone receptor (HR) subtype triple negative, increasing tumor size, low differentiation grade, and high TNM stage were risk factors associated with overall subsequent malignancies. Surgical implantation reconstruction was risk factor for lung/bronchus cancer. Even though BC patients had a favorite 5-year survival, their long-term survival was affected by subsequent malignancies, especially for lung/bronchus cancer with high mortality. Nearly 13% BC survivors suffered from subsequent malignancies. Increased risk was related to HER2/HR triple negative and advanced TNM stages. Radiotherapy and surgery were protective factors. Our findings may inform the subsequent cancer counseling of female BC survivors.