Phase I study of concomitant chemoradiotherapy with paclitaxel, fluorouracil, gemcitabine, and twice-daily radiation in patients with poor-prognosis cancer of the head and neck.

Purpose: We previously demonstrated high locoregional control, in patients with poor-prognosis head and neck cancer (HNC), using paclitaxel, 5-fluorouracil, hydroxyurea, and concomitant hyperfractionated radiotherapy. In the present phase I trial, gemcitabine, a novel antimetabolite with strong radiation-enhancing activity, replaces hydroxyurea. We sought to determine the recommended phase II dose and clinical efficacy in poor-prognosis HNC patients.

Experimental Design: Seventy-two patients enrolled. Eligibility criteria included recurrent or second primary HNC, metastases or expected 2-year survival <20%. Chemoradiotherapy consisted of 5-fluorouracil, 600 mg/m(2)/d, for 5 days; paclitaxel, 100 mg/m(2) on Day 1; and concurrent 1.5 Gy twice-daily radiation for 5 days. Gemcitabine was dose escalated, 50-300 mg/m(2) on day 1. Cycles repeated every 14 days until the completion of chemoradiation. Dose-limiting toxicities (DLTs) included: neutropenic fever; grade > or =4 neutropenia or thrombocytopenia for >4 days; grade > or =4 mucositis or dermatitis for >7 days; or grade 3 toxicity necessitating chemotherapy dose reductions. Non-DLT dose reductions in 5-fluorouracil and/or paclitaxel were allowed.

Results: Seventy-nine percent of assessable patients experienced a clinical response. Five-year actuarial survival is 33.0%, and locoregional control is 61.4%. The recommended phase II dose of gemcitabine in this regimen is 100 mg/m(2) during cycles 1-5 (1 of 7 patients with DLT) or 200 mg/m(2) delivered only during cycles 3-5 (3 of 19 with DLT). Grades 3 and 4 mucositis (56 and 21%, respectively) and dermatitis (25 and 21%, respectively) were common.

Conclusions: Gemcitabine, 5-fluorouracil, paclitaxel, and twice-daily radiation, delivered on alternating weeks, is active in patients with poor-prognosis HNC, although severe mucositis limits the clinical applicability of this regimen. Refinements in radiotherapy, including intensity-modulated radiation therapy, may improve the tolerance for this regimen.