Outcomes and prognostic factors of survival after pulmonary resection for metastatic gastric cancer.

OBJECTIVES Gastric cancer is the most common malignant tumour in Japan. Because gastric cancer metastases to the lung generally occur as lymphangitic carcinomatosis or numerous lesions, metastasectomy is rarely indicated. Therefore, the role of resectable pulmonary metastasectomy in gastric cancer is still unclear. The objective of this study was to determine the surgical outcomes and prognostic factors for survival after pulmonary resection of resectable metastatic gastric cancer. METHODS The database of the Metastatic Lung Tumor Study Group of Japan was retrospectively reviewed. Between March 1980 and March 2011, 3831 patients underwent pulmonary metastasectomy. Fifty-one patients undergoing surgery for metastatic gastric cancer were analysed, and the survival parameters and prognostic factors after pulmonary metastasectomy were determined. RESULTS The median time to recurrence after lung resection was 6 months (range, 0-29 months). The overall 5-year survival rate after pulmonary metastasectomy was 28%, and the median survival time was 29 months. Both univariate and multivariate analysis found that a disease-free interval <12 months was a poor prognostic factor (P = 0.01, P = 0.04, respectively). For 43 patients with a disease-free interval ≥12 months, the 5-year survival rate was 31%. CONCLUSIONS While resectable pulmonary metastases from gastric cancer are rare, a relatively good surgical outcome is expected for selected patients with disease-free intervals longer than 12 months.