Long-term survival of nasopharyngeal carcinoma patients with Stage II in intensity-modulated radiation therapy era

Abstract

Objectives: To evaluate the long-term survival and the role of chemotherapy in nasopharyngeal carcinoma (NPC) patients in Stage II treated by intensity-modulated radiation therapy (IMRT). Methods: Three hundred and eleven NPC patients in Stage II were reviewed. All were treated with IMRT with or without chemotherapy, with 191, 20 and 100 patients being defined as T1N1M0, T2N0M0 and T2N1M0 stage, respectively. Results: At a median follow-up of 57 months, the 5-year overall survival, disease-specific survival, distant metastasis-free survival, loco-regional relapse-free survival (LRRFS) and progression-free survival were 91.1, 93.5, 90.6, 95.9 and 87.6%, respectively. T2N1 patients had significant poorer survival outcomes than T1N1 patients, with T2N0 patients in between. Further analysis showed that the addition of chemotherapy could only improve LRRFS [hazard ratio (HR) 0.263, 95% confidence interval (CI) 0.083-0.839, P = 0.024], especially for T1N1 patients (HR 0.209, 95% CI 0.046-0.954, P = 0.043). For those in the T2N1M0 group, chemotherapy, as used in our series, added no benefit to any endpoint. Conclusions: IMRT in NPC patients in Stage II was quite therapeutic; however, different subgroups have distinct survival outcomes. Distant metastasis was the main failure pattern, especially for those with T2N1 disease, and the chemotherapy currently in use failed to treat subclinical metastatic foci effectively. Further prospective study is warranted to find out the role and the optimal schedule of chemotherapy in this subgroup of patients.