Treatment results for nasopharyngeal carcinoma in the modern era: the Hong Kong experience

Abstract

Purpose: To analyze the treatment results achievable for nasopharyngeal carcinoma in the modern era to identify the key failures for future improvement and to provide an updated baseline for future trials.

Methods and materials: The results of 2687 consecutive patients treated at all public oncology centers in Hong Kong during 1996-2000 were retrospectively analyzed. The stage distribution (by American Joint Committee on Cancer and International Union Against Cancer staging system, 1997) was 7% Stage I, 41% Stage II, 25% Stage III, and 28% Stage IVA-B. All patients were irradiated with 6-MV photons and the median total dose was 66 Gy. Only 23% of patients had additional treatment with chemotherapy.

Results: The 5-year local, nodal, and distant failure-free rates were 85%, 94%, and 81%, respectively; patients with local failure had significantly higher risk of nodal and distant failures. The 5-year progression-free, overall, and cancer-specific survival rates were 63%, 75%, and 80%, respectively. The presenting stage was the most important prognostic factor for all endpoints: with overall survival decreasing from 90% for Stage I to 58% for Stage IVA-B. The results achieved by the 2070 patients treated by radiotherapy alone were almost identical to that of the whole series, the distant failure-free rate among patients with locoregional control was 89% for Stage I-II and 75% for Stage III-IVB. The 860 patients (32%) staged with magnetic resonance imaging achieved significantly better results than those staged by computed tomography, the overall survival being 93% vs. 83% for Stages I-II, and 72% vs. 63% for Stages III-IVB (p = 0.001).

Conclusions: Treatment results for nasopharyngeal carcinoma have substantially improved in the modern era; future trials should be based on updated baseline results. Further reduction of distant failure is important for future breakthrough, particularly for patients with advanced disease.