Prognostic value of the number of involved nodes after neck dissection in oropharyngeal and oral cavity carcinoma

PURPOSE: To evaluate the relationship between the number of positive nodes and probabilities of locoregional control and survival in patients with invasive squamous cell carcinomas of the oral cavity and oropharynx. MATERIAL AND METHODS: Between 1976 and 1993, we treated with curative intent 183 patients (median age: 56 years; standard deviation: 10 years). Seventy-nine patients (43%) had oropharyngeal primary invasive carcinoma and 104 (57%) had oral cavity (excluding the lip) primary invasive carcinoma. Patients with simultaneous primary lesion or visceral metastases were excluded from the analysis. All the patients had neck dissection with at least six nodes to analyse. One-hundred fifty-nine patients (87%) underwent resection of the primary lesion and 158 (86%) were treated postoperatively with external beam irradiation alone or combined with interstitial implant (median dose: 60 Gy; standard deviation: 10 Gy). Average follow-up was 52 months. RESULTS: The overall 5-year survival rate using the Kaplan-Meier method was 42.6%. The 5-year survival rates were 60.0% when lymph nodes were histologically negative, 39.5% when one lymph node was positive, 28.0% when two lymph nodes were positive and 24.4% when three or more lymph nodes were positive (P = 0.0004). The number of positive nodes did not significantly influence the specific disease-free survival and locoregional control rates. CONCLUSION: Patients with one or more positive neck nodes must have postoperative treatment.