Phase I trial of escalating-dose irinotecan given weekly with cisplatin and concurrent radiotherapy in locally advanced esophageal cancer.

PURPOSE: To identify the maximum-tolerated dose and dose-limiting toxicity (DLT) of weekly irinotecan combined with cisplatin and radiation in esophageal cancer. PATIENTS AND METHODS: Nineteen patients with clinical stage II to III esophageal squamous cell or adenocarcinoma were treated on this phase I trial. Induction chemotherapy with weekly cisplatin 30 mg/m2 and irinotecan 65 mg/m2 was administered for four treatments during weeks 1 to 5. Radiotherapy was delivered weeks 8 to 13 in 1.8-Gy daily fractions to a dose of 50.4 Gy. Cisplatin 30 mg/m2 and escalating-dose irinotecan (40, 50, 65, and 80 mg/m2) were administered on days 1, 8, 22, and 29 of radiotherapy. DLT was defined as a 2-week delay in radiotherapy for grade 3 to 4 toxicity.
RESULTS: Minimal toxicity was observed during chemoradiotherapy, with no grade 3 or 4 esophagitis, diarrhea, or stomatitis. DLT caused by myelosuppression was seen in two of six patients treated at the 80-mg/m2 dose level, thus irinotecan 65 mg/m2 was defined as the recommended phase II dose. Dysphagia improved or resolved after induction chemotherapy in 13 (81%) of 16 patients who reported dysphagia before therapy. Only one patient (5%) required a feeding tube. Six complete responses (32%) were observed, including four pathologic complete responses in 15 patients selected to undergo surgery (27%).
CONCLUSION: Cisplatin, irinotecan, and concurrent radiotherapy can be administered on a convenient schedule with relatively minimal toxicity and an acceptable rate of complete response in esophageal cancer. Further phase II evaluation of this regimen is ongoing. A phase III comparison to fluorouracil or taxane-containing chemoradiotherapy should be considered.