Prognostic value of early radiological response to first-line platinum-containing chemotherapy in patients with metastatic nasopharyngeal carcinoma

Background To explore the prognostic value of early radiological response (ERR) to first-line platinum-containing chemotherapy in patients with metastatic nasopharyngeal carcinoma (mNPC), as well as its correlation with the best radiological response (BRR). Patients and methods A total of 756 mNPC patients with measurable lesions who received first-line platinum-containing chemotherapy were enrolled in this study. ERR was defined as complete or partial response after 6 weeks of chemotherapy according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. We performed survival analyses according to the radiological response after repeated chemotherapy. Log-rank test and Cox regression were used to analyze the survival data. Results About 470 patients achieved ERR and 78 patients achieved subsequent response (objective response after repeated chemotherapy). ERR patients had better OS (P < .001, median OS: 34.3 vs 22.2 months) and PFS (P < .001, median PFS: 10.2 vs 7.4 months) than non-ERR ones. ERR (OS: HR = 0.591, 95% CI, 0.495-0.705, P < .001, PFS: HR = 0.586, 95% CI, 0.500-0.686, P < .001) was independently prolonged survival compared with non-ERR ones. Besides, ERR was significantly correlated with the BRR (Kappa: 0.73; Pearson: 0.74, P < .001), and had significantly longer OS and PFS than patients with subsequent response, respectively. Conclusion ERR is an independent prognostic factor in determining survival in mNPC patients received first-line platinum-containing chemotherapy, which may be a more sensitive predictor to assess overall efficacy of systemic treatment than BRR in mNPC. Prospective validation studies are needed.