Objective To systematically evaluate the risk of primary lung cancer in breast cancer patients.
Methods A computer-based search was conducted for the English literatures about the risk of primary lung cancer in breast cancer patients in Medline, Scopus and Embase databases. Two researchers independently screened the literatures, extracted the data and assessed the risk of bias. The statistical analysis was performed using the Stata 15.5 software.
Results A total of 7 references were included, and the overall risk of primary lung cancer in female breast cancer patients was slightly higher than that in the general population (SIR: 1.18, 95%CI: 1.09-1.27). Subgroup analysis showed that the risk of lung cancer was significantly increased in women aged < 50 years after diagnosis of breast cancer (SIR: 1.99, 95%CI: 1.48-2.69).
Conclusion Compared with the general population, the risk of primary lung cancer is increased in female breast cancer patients, especially in young women with breast cancer.