Meta-analysis of survival outcomes following surgical and non surgical treatments for colorectal cancer metastasis to the lung.

Abstract

Controversy exists regarding the optimal management of colorectal lung metastases (CRLM). This meta-analysis compared surgical (Surg) versus interventional (chemotherapy and/or radiotherapy) and observational non-surgical (NSurg) management of CRLM. A systematic review of the major databases including Medline, Embase, SCOPUS and the Cochrane library was performed. One randomized and nine observational studies including 2232 patients: 1551 (69%) comprised the Surg cohort, 521 (23%) the interventional NSurg group and 160 (7%) the observational NSurg group. A significantly higher overall survival (OS) was observed when Surg was compared to interventional NSurg at 1 year (Surg 88%, 310/352; interventional NSurg 64%, 245/383; odds ratio (OR) 2.77 (confidence interval (CI) 1.94-3.97), P = 0.001), at 3 years (Surg 59%, 857/1444; interventional NSurg 26%, 138/521; OR 2.61 (CI 1.65-4.15), P = 0.002), at 5 years (Surg 47%, 533/1144; interventional NSurg 23%, 45/196; OR 3.24 (CI 1.42-7.39), P = 0.009) and at 10 years (Surg 27%, 306/1122; interventional NSurg 1%, 2/168; OR 15.64 (CI 1.87-130.76), P = 0.031). Surg was associated with a greater OS than observational NSurg at only 1 year (Surg 92%, 98/107; observational NSurg 83%, 133/160; OR 6.69 (CI 1.33-33.58), P = 0.037) and was similar to observational NSurg at all other OS time points. Comparable survival was observed among Surg and overall NSurg cohorts at 3- and 5-year survival in articles published within the last 3 years. Recent evidence suggests comparable survival with Surg and NSurg modalities for CRLM, contrasting to early evidence where Surg had an improved survival. Significant selection bias contributes to this finding, prompting the need for high powered randomized controlled trials and registry data.