Abstract
BACKGROUND: The aim of this study was to verify the predictors of recurrence and survival in lung adenocarcinoma patients with experiences of breast cancer therapies. METHODS: We retrospectively reviewed consecutive patients who were treated at our hospital for lung adenocarcinoma from 2004/01 to 2014/03. The patients were divided into groups of those with lung adenocarcinoma alone and those with lung and breast cancer. Kaplan-Meier plots and log-rank tests were used to estimate outcomes. RESULTS: 54 patients with lung adenocarcinoma and breast cancer were compared with 457 patients with single primary lung adenocarcinomas. After propensity score matching with control of age, operation type, smoking status and pathologic stage, tumor differentiation, recurrence rate and tumor size were significantly different between two groups. The significant predictors for recurrence included undergone chemotherapy (HR = 25, p < 0.001), moderate/poor differentiation (HR = 8.125, p = 0.012), tumor size ≧ 2 cm (HR = 15, p < 0.001), LVSI (HR = 13.67, p = 0.031) and GGO ratio < 50% (HR = 14.667, p = 0.014). The significant prognostic factors for survival were accepted chemotherapy (HR = 6.182, p = 0.021), LVSI (HR = 22, p = 0.012) and GGO ratio < 50% (HR = 9.143, p = 0.045). Kaplan-Meier analysis revealed that patients with lung adenocarcinoma and breast cancer had a better 5-year disease-free survival (p = 0.009), while the Her2-negative patients obtained a better overall survival (p = 0.038). CONCLUSIONS: In patients with breast cancer and lung adenocarcinoma, independent risk factors of recurrence were undergone chemotherapy, moderate/poor differentiation, tumor size ≧ 2 cm, LVSI and GGO ratio < 50%. Only undergone chemotherapy, LVSI and GGO ratio < 50% were significant poor predictors for survival. However, patients with metachronous lung adenocarcinoma and breast cancer had better disease-free survival and less tumor recurrence than patients with lung adenocarcinoma alone.