Pilot study of organ preservation multimodality therapy for locally advanced resectable oropharyngeal carcinoma

The purpose of this study was to determine the early efficacy and toxicity of a new multimodality organ-preservation regimen for locally advanced, resectable oropharyngeal squamous cell carcinoma (SCC). Patients with T3-4N0-3M0 or T2N2-3M0 oropharyngeal SCC were eligible for this Phase II study. Patients needed the physiologic reserve for surgery and technically resectable tumors. Induction carboplatin (area under the curve = 6) and paclitaxel (200 mg/m²) × 2 cycles (q21 days) were given. Objective responders received definitive radiotherapy (XRT), 70 Gy/7 weeks with concurrent weekly paclitaxel. Initially, the dose of paclitaxel was 50 mg/m²/week; because of mucosal toxicity it was reduced to 30 mg/m²/week. Patients with N2-3 disease received post-XRT neck dissection and 2 more cycles of "adjuvant" chemotherapy. In the first 22 patients, the neutropenic fever rate was 27%. Although there has been no grade IV-V toxicity from induction therapy, grade II-III toxicity resulted in an unacceptable delay in starting XRT in 14% of patients. The response rate to induction chemotherapy was 91%. Grade III mucositis occurred in all patients during concurrent chemoradiotherapy. One patient died of pneumonia during concurrent chemoradiotherapy after receiving 26 Gy and 3 doses of paclitaxel 50 mg/m². No dose-limiting toxicity occurred in 15 patients treated with concurrent paclitaxel 30 mg/m²/week. Actuarial overall survival at 18 months is 82%; local-regional control is 86%. To date, distant metastases have not developed in any patients. This regimen has intense but acceptable acute toxicity. The maximum tolerated dosage of weekly paclitaxel during standard continuous-course XRT is confirmed to be 30 mg/m²/week. The treatment efficacy of this regimen (response rate and short-term local-regional and distant control) is encouraging. Accrual continues to obtain long-term toxicity, efficacy, and quality-of-life data.