Long-term survival after cisplatin-based induction chemotherapy and radiotherapy for nasopharyngeal carcinoma: A pooled data analysis of two phase III trials

5524 Background: To evaluate the long-term treatment outcome in patients with advanced stage nasopharyngeal carcinoma (NPC) treated by cisplatin-based induction chemotherapy and radiotherapy (CRT) versus radiotherapy alone (RT). Methods: The updated records of two previously reported phase III studies (the Asian-Oceania Clinical Oncology Association trial and the Guangzhou trial). testing the benefit of adding induction chemotherapy to radiotherapy in NPC were reviewed and the data were pooled together for analysis. A total of 784 patients were included for analysis, with equal number of patients in both the CRT and RT arms. The induction chemotherapy consisting of 2–3 cycles of cisplatin 100 mg/m2 day 1, bleomycin 10 mg/m2 day 1 & 5, and fluorouracil 800 mg/m2 day 1–5, or cisplatin 60 mg/m2 day 1 and epirubicin 110 mg/m2 day 1. Radiotherapy was given to the nasopharynx and neck using megavoltage radiation, with a median dose of 70 Gy. Treatment compliance was 92.6% in the CRT arm and 98% in the RT arm. The median follow-up time for surviving patients was 67 months. Analysis was done by intention to treat. Results: The addition of induction chemotherapy to radiotherapy was associated with a decrease in relapse by 14.3% and cancer deaths by 12.9% at 5 years. The 5-year relapse-free survival rate was 50.9% in the CRT arm and 42.7% in the RT arm (p=0.014), and the 5-year disease-specific survival rate was 63.5% in the CRT arm and 58.1% in the RT arm (p=0.029). The median disease-specific survival was not yet reached in the CRT arm and it was 82 months in the RT arm. The incidence of loco-regional failure and distant metastases were reduced by 18.3% and 13.3% at 5 years respectively with induction chemotherapy. There was no significant difference in the failure patterns between the 2 arms. Conclusions: The addition of cisplatin-based induction chemotherapy to radiotherapy was associated with a modest but significant improvement in survival in advanced stage NPC. No significant financial relationships to disclose.