What is the appropriate surgical strategy for pulmonary metastasis of colorectal cancer?

Pulmonary metastasectomy is considered to be a feasible method for selected colorectal cancer (CRC) patients. This study aimed to optimize the individualized surgical strategy of pulmonary metastasectomy, especially in choice of surgery extent and systematic mediastinal lymph nodes dissection. Data of 267 CRC patients who underwent pulmonary metastasectomy from July 2011 to July 2017 in Shanghai Cancer Center Fudan University were reviewed. Recurrence-free survival (RFS), overall survival (OS) and other clinical characteristics were compared between patients who accepted different surgical strategy. A total of 93 (34.8%) patients underwent lobectomy, 162 (60.7%) wedge resection, and 12 (4.5%) segmentectomy. Mediastinal lymph nodes dissection or sampling was performed in 106 (39.7%) patients. The median follow-up phase was 32.5 months (range 7.2–104.7 months). Patients were divided into 2 groups according to the surgical extent, lobectomy group and sublobar resection group. The median RFS and OS were 46.4 and 76.5 months for patients underwent, respectively. In the patients whose tumor diameter was ≥ 1.5 cm, RFS (5-year; 44.9% vs 29.8%, log-rank P = .03; hazard ratio, 0.71; 95% CI 0.52–0.89, P = .026) was better in the lobectomy group; however, no difference was found in OS. Meanwhile, in the patients whose tumor size was <1.5 cm, no difference was observed in RFS, as well as in OS. In the patients with metastatic lesion size ≥1.5 cm, a trend towards better RFS was found in patients received lymph nodes dissection, but it did not reach statistical significance. Lobectomy has more curative significance for CRC patients with single pulmonary metastatic lesion ≥1.5 cm. Systematic mediastinal lymph nodes dissection did not improve clinical outcome for CRC patients occurred pulmonary metastasis.