Induction Chemotherapy Followed by Concurrent Chemoradiotherapy in the Treatment of Locally Advanced Base of Tongue Cancer

Abstract

To report our experience with the treatment of base of tongue (BOT) cancer using induction chemotherapy followed by concurrent chemoradiotherapy. From 11/1998–6/2002, 42 patients with locally advanced Stage III (n = 5) or stage IV (n = 37) BOT cancer were treated with 2 cycles of induction carboplatin (area under the curve 2) and paclitaxel (135 mg/m2) followed by concurrent paclitaxel, continuous infusion 5-fluorouracil, hydroxyurea, and 1.5 Gy BID radiation for 5 consecutive days of treatment followed by a 9-day break during which no additional treatment was given. Four patients who started, but did not complete treatment, were excluded from the analysis. The median dose to gross tumor was 72.5 Gy (R 59 Gy-75.5 Gy). Only two patients received less then 70 Gy. All patients underwent CT based planning. Neck dissections were planned on all patients with N2a–N3 disease. The median follow-up for all patients was 58 months (R 13–87 months) and for living patients 62 months (R 13–73 months). The breakdown by stage was as follows: T stage (10 T1, 9 T2, 8 T3, 15 T4) and N stage (5 N0, 6 N1, 5 N2a, 12 N2b, 10 N2c, 4 N3). Following therapy, 98% of patients (41/42) demonstrated a clinical complete response; neck dissections were positive for metastatic disease in 48% (11/23) and directed biopsies of the primary tumor were positive in 0% (0/31). There were three local failures, one regional failure, and four distant failures. The 2 and 5 year overall survival was 83.3% (95% CI: 68.2–91.7) and 70.4% (95% CI: 53.6–82.0), respectively. The 2 and 5 year disease-free survival was 85.3% (95% CI: 70.2–93.1) and 82.7% (95% CI: 67.0–91.4), respectively. The crude local failure rate was 7% (3/42). Loco-regional progression free survival at 5 years was 90.5% (95% CI: 75.8–96.2). Grade 3 or higher toxicity occurred in 36% of patients, while 12% experienced chemotherapy-related peripheral neuropathy. Feeding tubes were placed in 69% of treated patients, the majority of which were placed prior to starting radiotherapy. Pre-treatment swallowing function evaluation was performed on 38 patients and 84% had mild to severe dysphagia. At 6 months following treatment completion, the number of patients still requiring feeding tube and tracheostomy were 8 (19%) and 7 (17%), respectively. Six patients developed new primary cancers during follow-up, one of which was attributed to treatment-induced carcinogenesis. Our results demonstrate the effectiveness of induction chemotherapy and concurrent chemoradiotherapy delivered on a 14-day schedule for locally advanced base of tongue cancer.