Multicenter Phase 2 Study of Peri-Irradiation Chemotherapy Plus Intensity Modulated Radiation Therapy With Concurrent Weekly Docetaxel for Inoperable or Medically Unresectable Nonmetastatic Gastric Cancer

Abstract

To assess the efficacy and feasibility of concurrent chemoradiation therapy (CCRT) plus preradiation and postradiation chemotherapy for patients with nonmetastatic gastric carcinoma who do not undergo surgery. Patients with inoperable (due to medical comorbid conditions or patient's refusal to undergo surgery) or unresectable gastric cancer received up to 2 21-day cycles of preradiation and postradiation chemotherapy (docetaxel 37.5mg/m2 on days 1 and 8, cisplatin 25mg/m2 on days 1-3, and a continuous infusion of fluorouracil [FU] 750mg/m2 on days 1-5), respectively. CCRT between preradiation and postradiation chemotherapy was initiated on day 43 and consisted ofintensity modulated radiation therapy (50.4Gy) plus concurrent docetaxel 20mg/m2 weekly for 6weeks. 36 patients were evaluable; 21 patients with comorbid conditions were unsuitable for surgery (group 1), 8 had unresectable disease (group 2), and 7 refused surgery (group 3). The clinical complete response (cCR) rate for the 36 evaluable patients was 36% (95% confidence interval [CI], 19%-53%) and the overall response rate was 83% (95% CI, 75%-97%). The median survival time and estimated 2-year survival rate were 25.8months (95% CI, 7.1-44.5months) and 52% (95% CI, 38%-67%), respectively. The estimated median OS and 2-year OS rates for groups 1, 2, and 3 were 37.0months (95% CI, 7.9-66.1months) and 52% (95% CI, 31%-73%), 17.7months (95% CI, 7.8-27.6months) and 20% (95% CI, 0%-49%), and 38.9months (95% CI, 16.6-58.3months) and 67% (95% CI, 30%-100%), respectively. Achieving a cCR was associated with significantly better overall survival (P=.004) and progression-free survival (P=.003). The most common grade 3 or greater toxicity during the chemotherapy phase was neutropenia. Common grade 3/4 toxicities during CCRT were nausea and vomiting. This regimen is tolerable and shows promising efficacy in inoperable or medically unresectable GC.