Abstract
BACKGROUND: Breast cancer and lung cancer are the top two malignancies in the female population and the number of patients with breast cancer and subsequent primary lung cancer has increased significantly in recent years. However, the unique molecular characteristics of this group of patients remains unclear. PURPOSE: To identify the genomic and transcriptome characteristics of primary lung adenocarcinoma patients with previous breast cancer by comparison with single primary lung adenocarcinoma (SPLA) patients. METHODS: The tumor and normal pulmonary tissue specimens of ten primary pulmonary adenocarcinoma patients with previous breast cancer (multiple primary cancer, MPC) and ten SPLA patients were prospectively collected. The whole exome sequencing (WES) and RNA sequencing (RNA-seq) were performed to analyze the gene mutation and expression differences between MPC and SPC patients. RESULTS: The results of WES indicated that the mutations of TRIM73, DLX6 and CNGB1 only existed in MPC patients. The results of RNA-seq manifested the occurrence of second primary lung adenocarcinoma in breast cancer patients was closely associated with cytokine-cytokine receptor action, autophagy, PI3L-Akt, cAMP and calcium ion signaling pathways. Besides, the expression levels of FGF10 and VEGFA genes were significantly increased in MPC patients. CONCLUSION: The occurrence of second primary lung adenocarcinoma may be related to the cytokine-cytokine receptor action, autophagy, PI3L-Akt, cAMP and calcium ion signaling pathways. Furthermore, the mutations of TRIM73, DLX6 and CNGB1 and high expression of FGF10 and VEGFA might play an important role in the development of lung adenocarcinoma in breast cancer patients. However, more in-depth investigations are needed to verify above findings.