Tumor regression grade and survival after neoadjuvant treatment in gastro-esophageal cancer: A meta-analysis of 17 published studies

Introduction Major pathologic regression after neoadjuvant therapy is a strong and favorable prognostic factor in several types of cancer (breast, rectal and bladder). This information is less clear and has yet to be systematically evaluated in upper gastrointestinal tumors. We performed a meta-analysis to evaluate the prognostic impact of tumor regression after preoperative therapy on disease-free survival (DFS) and overall survival (OS) in gastro-esophageal cancer patients. Methods we searched for relevant articles in PubMed, SCOPUS, Web of Science, CINAHL, LILACS, Ovid, Cochrane Library, Google Scholar and Embase up to June 2, 2016. Data of tumor regression (complete or near-complete pathologic response) that independently correlated with OS and DFS in multivariate analysis were extracted, and the proper hazard ratios (HRs) with corresponding 95% confidence intervals (95% CIs) were pooled according to the random effect model. Results a total of 17 studies—which included 3145 patients—were considered in the final analysis. Major pathologic response was significantly related with better OS (HR 0.46, 95% CI 0.32–0.66, P < 0.001) and DFS (HR = 0.40, 95% CI 0.26–0.62, P < 0.001). Pathologic complete response (pCR) or major tumor regression were associated with the same degree of benefit in outcome compared to no or minimal pathologic regression, regardless of histology. Conclusion major pathologic response is associated with a significant improvement in OS compared to no response or minor pathologic changes after neoadjuvant therapy in gastro-esophageal cancers. This should be considered a robust prognostic factor to guide postoperative treatment and follow-up.