ABSTRACT
@#Objective To explore the association between radiotherapy and the risk of subsequent primary lung cancer in female patients with breast cancer. Methods The EMbase, Web of Science, PubMed, CNKI, VIP and WanFang databases were searched from the establishment date to July 1, 2021. The relative risk (RR) with 95% confidence interval (CI) were combined and all statistical analyses were performed by STATA 12.0 software. Results A total of 10 publications including 466 510 participates from 14 studies were included. The meta-analysis indicated that radiotherapy was a risk factor for the occurrence of second primary lung cancer among female breast cancer patients [RR=1.45, 95%CI (1.18, 1.78), P<0.001]. Subgroup analysis based on the relative position of breast cancer and lung cancer was conducted and the results demonstrated that radiotherapy only increased the incidence rate of ipsilateral lung cancer [RR=1.27, 95%CI (1.10, 1.45), P=0.001], without significant change of the risk of contralateral lung cancer [RR=1.16, 95%CI (0.77, 1.74), P=0.487]. Conclusion Radiotherapy is one of the risk factors for subsequent primary pulmonary carcinoma among female breast cancer patients, especially for ipsilateral lung carcinoma. However, more high-quality studies are still needed to verify above findings.