Adjuvant chemoradiation therapy with 5-FU/LV (INT-0116) versus S-1 chemotherapy in completely resected gastric cancer: Practice pattern and feasibility at a single institution.

Abstract

57 Background: Considering the high incidence of gastric cancer worldwide, large-scaled phase III adjuvant trials have been relatively scarcely reported. Until 2010, there have been two large-scaled adjuvant trials in gastric cancer that showed survival benefit from adjuvant chemotherapy +/- radiotherapy: S-1 monotherapy and chemoradiation therapy (CRT) with 5-FU/LV. There has been no direct comparison between S-1 monotherapy and CRT. We analyzed the practice pattern of adjuvant treatment at single institution in Korea in terms of patient’s preference, compliance rate, adverse events between CRT and S-1. Methods: From January 2008 to July 2009, 405 gastric cancer patients who had received adjuvant therapy after curative resection were included for the study. The CRT regimen was INT 0116 protocol. The S-1 monotherapy was to administer 40-60 mg bid, for 28 days, every 6 weeks (8 cycles). Results: Of the total 405 patients, 244 (60.3%) patients had CRT and 161 (39.7%) patients had S-1 monotherapy. The median age was 54 years (range, 24-80) and most of the patients were ECOG PS 0-1. S-1 group was more common than CRT group in Stage II (52.2% for S-1 vs. 47.8% for CCRT) and CRT group was more common in stage III-IV (72.4% for CCRT vs. 27.6% for S-1, p<0.001). The patients’ compliance for the planned treatment was significantly higher in CRT group (95.1% vs. 72.8%, p<0.001). Most common reason for cessation of S-1 therapy was patients’ refusal. For severe adverse events, grade 3-4 neutropenia was substantially more frequent in CRT group (40.2% vs. 8.7%, p<0.001) and GI toxicities of nausea and mucositis were frequent in CRT group when compared with S-1 group (CRT vs S-1; nausea, 5.7% vs <1%; p=0.002; mucositis, 7.4% vs 2.5%; p=0.034). Conclusions: Patients with advanced stage (III–IV) preferred CRT to S-1. The compliance was significantly higher for the CRT group despite of higher incidence of adverse events.