Intensified concomitant chemoradiotherapy with and without filgrastim for poor-prognosis head and neck cancer.

Abstract

We previously demonstrated high locoregional control rates in patients with poor-prognosis head and neck cancer using fluorouracil (5-FU), hydroxyurea (HU), and concomitant radiotherapy (FHX). In two trials reported here, we added cisplatin with and without granulocyte colony-stimulating factor (G-CSF) to 5-FU, HU, and concomitant radiotherapy. Eligible patients had failed to respond to prior local therapy (group 1); previously untreated patients with unresectable and/or metastatic disease and a projected 2-year survival rate less than 10% were also eligible (group 2). Chemoradiotherapy consisted of 1.8 to 2.0 Gy on days 1 to 5 with simultaneous infusional 5-FU at 800 mg/m2/d and HU administered every 12 hours for 11 doses at escalating doses. Cisplatin was administered at 100 mg/m2 during every other cycle. Cycles were repeated every 14 days until completion of radiotherapy. In study 2, G-CSF was added on days 6 to 13 at 5 micrograms/kg/d. Acute and cumulative myelosuppression limited the feasibility of adding cisplatin to FHX without G-CSF. G-CSF allowed for escalation of HU to 1 g orally every 12 hours without dose-limiting acute toxicity during cycles 1 and 2. Dose-limiting cumulative toxicity consisted of severe or life-threatening myelosuppression and mucositis. To decrease total treatment duration and, thus, cumulative toxicity, a hyperfractionated radiation therapy schedule was investigated using the established chemotherapy doses with 1.5 Gy twice daily on days 1 to 5 (75 Gy over five treatment cycles). No increase in acute toxicities was seen; cumulative toxicities remained frequently severe or life-threatening. Thirty-eight of 45 assessable patients responded. The median survival duration was 12 months for both groups. Median time to treatment failure was 8 months for group 1 and has not been reached for group 2. At 1 year, local control rates were 74% and 91% for groups 1 and 2, respectively. The addition of cisplatin to 5-FU, HU, and concomitant radiotherapy is feasible using G-CSF. The high locoregional control rate and failure-free interval justify further investigation of this regimen in previously untreated patients.