Abstract: The number of the patients with double primary cancers is increasing. Breast cancer and lung cancer are the two most common malignant tumors in women, seriously threatening the health of the majority of women. Although the lung is one of the most common metastatic sites of breast cancer, in recent years, there have been increasing cases of primary lung cancer in patients with breast cancer. The incidence of double primary cancers with breast cancer as the first primary cancer is much higher than that with lung cancer as the first primary cancer. Primary breast cancer is closely related to the occurrence and development of lung cancer. This article reviews the epidemiology, clinicopathological features, diagnosis and treatment of double primary breast cancer and lung cancer with breast cancer as the first cancer.