Survival outcomes of lung metastases from colorectal cancer treated with pulmonary metastasectomy or modern systemic chemotherapy: a single institution experience

BACKGROUND: Although pulmonary metastasectomy is an accepted treatment strategy for resectable lung metastases (LM) from colorectal cancer (CRC), its survival benefits are controversial. In contrast, recent advancements in chemotherapy have significantly improved metastatic CRC prognosis. This study aimed to evaluate survival outcome of LM from CRC in the age of newly developed chemotherapy. METHODS: We retrospectively reviewed 50 patients who underwent complete resection and 22 patients who received chemotherapy as definitive treatment for LM from resected CRC at our hospital. The present study was limited to patients who started treatment for isolated LM after molecular targeted drugs became available in Japan. RESULTS: Overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS) rates after pulmonary resection were 64.5%, 66.4%, and 32.6% at five years, respectively. OS and CSS rates of chemotherapy patients were 26.8% and 28.3% at five years, with a median progression-free survival time of 10.0 months. When compared the characteristics of surgical and chemotherapy patients, patients with pN factors of CRC (p = 0.013), smaller size (p < 0.001), larger number (p < 0.001), and bilateral (p < 0.001) LM received chemotherapy. Univariate analysis showed that multiple LM and rectal lesions were poor prognostic factors for OS (p = 0.012) and DFS (p = 0.017) in surgical patients, and rectal lesions were a poor prognostic factor for OS (p = 0.013) in chemotherapy patients. CONCLUSIONS: Pulmonary metastasectomy showed a favorable survival in patients with LM from CRC. Despite the high recurrence rate after metastasectomy and recent advances in chemotherapy, surgical resection could still be considered as a valid option among multidisciplinary treatments. TRIAL REGISTRATION: The research plan was approved by the Institutional Review Board of Shinko Hospital (No. 2142) on February 7, 2022.