Updated results of MSCMCC gastric cancer cohort: Indirect comparison between adjuvant chemoradiation and perioperative chemotherapy in gastric cancer patients.

Abstract

123 Background: In the western world gastric cancer patients are either treated with peri-operative chemotherapy or adjuvant chemoradiation and no direct comparisons of these two treatment strategies are available. In our referral gastric cancer center (MSCMCC) we have changed in January 2013 the treatment protocol from adjuvant chemoradiation (like in INT-0116 study) to peri-operative chemotherapy (ECF or CF regimen). Here we report the updated results of single institution indirect comparison of two treatment strategies in the treatment of gastric cancer patients. Methods: 139 consecutive pts who underwent gastrectomy between 2009-2015 treated at MSCMCC were identified in a cohort manner (2009-2012 radiochemotherapy: 60 pts; 2013-2015- peri-operative chemotherapy: 79 pts). The patients’ clinical characteristics were collected from medical records. All patients were followed for relapse and survival with median observation time of 57 and 17 months for chemoradiation and peri-operative chemotherapy respectively. Results: The patients’ characteristics were similar in two groups including, age, sex, ECOG status and Lauren-classification types. DFS was similar in both arms with 47% of patients in radiochemotherapy and 63% of peri-operative chemotherapy patients without relapse at 2 years cut-off (p=0.17). OS was not significantly different between the groups (p=0.783). The toxicity profile was similar in two cohorts, with only leukopenia reported more often in the chemoradiation group (grade 3-4: 43.3% vs 12.3%. p<0.001) and low platelet count (grade 3-4: 6.7% vs 3.7%; p=0.19).There was a trend for excessive mucositis (p=0.067) and diarrhea (p=0.051) in the chemoradiation group. Vomiting more often observed in the peri-operative chemotherapy group (grade 3-4: 29.6% vs 13.3%, p=0.032). Notable, no differences were reported for neutropenia, fatigue and weigth loss. Conclusions: This indirect comparison suggests that results of two modalities are similar in terms of RFS. Further follow up is needed to assess the impact on survival. The toxicity profile favours the peri-operative chemotherapy.