A phase I/II study of neoadjuvant chemotherapy followed by radiation with boost chemotherapy for advanced T-stage nasopharyngeal carcinoma

Purpose: Local recurrence is the most common site of failure for locally advanced nasopharyngeal carcinoma (NPC) treated with neoadjuvant cisplatin/5-fluorouracil (PF) and definitive radiation at our center. Based on this, we studied the addition of chemotherapy during the boost phase of radiation after neoadjuvant PF for advanced T-stage (T3–T4) NPC. This strategy was based on theoretical radiosensitization with chemotherapy during accelerated repopulation of the tumor with relatively radioresistant clonogens. Methods and Materials: Three cycles of neoadjuvant PF was followed by conventionally fractionated radiation with additional PF during the boost portion of the radiation course. An initial Phase I study was done to establish the maximum tolerated dose of concurrent PF. Results: Forty-four patients were enrolled. Six patients in Phase I defined the MTD for concurrent PF as: cisplatin 10 mg/m 2 /day and PF 320 mg/m 2 /day, on Days 1–5 during Weeks 6 and 7 of radiation therapy based on dose-limiting toxicities of mucositis, neutropenia, and thrombocytopenia. Forty-one patients were treated with concurrent therapy per protocol: complete, partial, and minor responses were seen in 23, 16, and 2 patients, respectively. Progression-free and overall survival rates at 5 years were 55% (95% CI, 41–75%) and 66% (95% CI, 52–85%), respectively. Seven of 11 tumor-related deaths were due to local recurrence. Nine of 10 patients with local recurrence had T4-stage disease at presentation. Local control of T4 disease was achieved in 74% of patients overall, and in 25% (1/4) with World Health Organization (WHO) type 1, 76% (16/21) with WHO type 2, and 90% (9/10) with WHO type 3 histology. Common toxicities included mucositis, dermatitis, fatigue, vomiting, and weight loss. Conclusions: This regimen was feasible and associated with promising overall survival. Local recurrence remains the major reason for treatment failure in advanced T-stage NPC, especially WHO types 1 and 2. Other strategies to improve local control in these patients should be investigated.