Objective: How important and predictive are clinical parameters and locoregional failure after radical radiotherapy of oropharyngeal carcinomas for the probability of the occurrence of distant metastases?
Patients and methods: From 1 August 1990 to 1 October 1998, 139 patients with carcinomas of the oropharynx were treated in a prospective study by radical radiotherapy and evaluated in regard to the clinical parameters reflex-otalgia, predominant structure of tumor growth, T-category, presence of involved lymph nodes, and smoking and drinking habits. Twenty-nine patients received a concomitant chemotherapy. Twenty-five out of 139 patients had a planned neck dissection after completion of radiotherapy. Ten patients received a salvage operation.
Results: The median follow up time was 24 months (range, 4 to 74). Two- and 5-year overall survival rates according to Kaplan Meier were 56.1 and 49.6%. The tumors were controlled in 77/139 patients (55%). The therapy failed in 62/139 patients (45%). Both groups, 62 patients with locoregional therapy failure and 77 patients with locoregionally control led tumors, were comparable in regard to performance status (Karnofsky index), age, gender, TNM-categories, histological differentiation, drinking habits, pretherapeutic diagnostics, total dose (Gy), and number of simultaneous chemotherapy cycles. Locoregional tumor control was significantly determined by the parameters reflex-otalgia (p < 0.0078), predominant growth pattern (p < 0.012), T-category (p < 0.03), and smoking (p < 0.0285). The median survival time of patients with locoregional failure is 17 months. At this moment 81% of locoregionally controlled patients are still alive. In 14/62 patients (23%) with locoregional failure, distant metastases were detectable against 4/77 (5%) of locally controlled patients, p < 0.0026. Probability of local control and distant metastases, predominantly pulmonary, reached a plateau after 24 months.
Conclusions: Locoregional tumor control, determined by several clinical parameters, is an important parameter for the probability of the development of distant metastases. Failure of local therapy is caused by the biologic aggressiveness of the tumor.