Postoperative chemoradiotherapy in gastric cancer -- a Phase I/II dose-finding study of radiotherapy with dose escalation of cisplatin and capecitabine chemotherapy.

We hypothesised that gastric cancer outcome could be improved with more effective and intensified postoperative chemoradiotherapy. This phase I/II study was performed to determine the maximal tolerated dose (MTD) and toxicity profile of postoperative radiotherapy with concurrent daily cisplatin and capecitabine. Patients were treated with capecitabine 1000 mg m(-2) twice a day (b.i.d.) for 2 weeks. Subsequently, patients received capecitabine (250-650 mg m(-2) orally b.i.d., 5 days week(-1)) and cisplatin (3-6 mg m(-2) i.v., 5 days week(-1)) according to an alternating dose-escalation schedule. Radiotherapy was given to a total dose of 45 Gy in 25 fractions. Thirty-one patients completed treatment. During chemoradiotherapy, eight patients developed nine items of grade III and one episode of grade IV (mainly haematological) toxicity. The MTD was determined to be cisplatin 5 mg m(-2) i.v. and capecitabine 650 mg m(-2) b.i.d. orally. This phase I/II study demonstrated that chemoradiotherapy with daily cisplatin and capecitabine is feasible in postoperative gastric cancer at the defined dose level and is currently being tested in a phase III multicenter study.