Adjuvant chemoradiation in gastric cancer: long-term outcomes and prognostic factors from a single institution.

Background: Adjuvant chemoradiotherapy (CRT) improves relapse-free (RFS) and overall survival (OS) in patients with resected gastric cancer. However, difficulties in standardizing an optimal surgical approach and a perceived higher toxicity compared with the perioperative approach have limited its widespread application in Europe. The aim of our study was to assess toxicity and long-term outcomes of adjuvant CRT at our institution.

Methods: A retrospective review (September 2001-January 2012) was completed of patients with resected gastric cancer who received adjuvant CRT (Macdonald regimen). Adverse events and completion rates, RFS and OS were estimated. Univariate and multivariate analyses of prognostic factors for OS were performed.

Results: Eighty-seven patients were included. Most had diffuse (52%) and locally advanced tumors (stage III-IV; 66.7%). D2 lymphadenectomy was performed in 80.5%. The most frequent grade 3-4 toxicities were gastrointestinal (28%) and stomatitis (20%), with 78.2% completing treatment. With a median follow-up of 115 months, 58.5% had relapsed, most of them distantly. Median RFS and OS were 9 and 24 months, respectively. Univariate analysis showed that performance status, stage and lymph node burden were significant factors for OS. In the multivariate study, only stage and lymph node burden remained as independent OS predictors.

Conclusions: Our implementation of the Macdonald regimen achieved worse outcomes than those reported in the INT-0116 trial. The rate of distant relapse remains unacceptably high. Higher rate of positive lymph nodes and of diffuse tumors could explain some differences. The use of perioperative chemotherapy, especially in patients with a poorer prognosis, might improve these results.