Comparing the efficacy of induction-concurrent with concurrent-adjuvant chemotherapy in locoregionally advanced nasopharyngeal carcinoma: a propensity score matching analysis

PURPOSE: This study aimed to compare the efficacy of induction-concurrent (IC-CCRT) with concurrent-adjuvant (CCRT-AC) chemotherapy in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) treated by intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Data on 834 patients with newly diagnosed, non-metastatic stage III-IVA (except T3N0) NPC receiving either IC-CCRT or CCRT-AC between July, 2004 and December, 2014 were retrospectively reviewed. Propensity score matching (PSM) method was adopted to balance prognostic factors and match patients. Survival outcomes of matched patients between IC-CCRT and CCRT-AC were compared. RESULTS: The median follow-up duration is 45.2 months (range, 1.07–145.4 months). Overall, 309 pairs were selected by PSM. Univariate analysis revealed the CCRT-AC group achieved significantly higher 3-year DFS (83.9% vs. 78.7 %; P = 0.014) and OS (87.6% vs. 87.0%; P = 0.031). Multivariate analysis also identified treatment group (IC-CCRT vs. CCRT-AC) as an independent prognostic factor for 3-year DFS (HR, 1.546; 95% CI, 1.113–2.149; P = 0.009) and OS (HR, 1.487; 95% CI, 1.035–2.136; P = 0.032). Subgroup analysis revealed IC-CCRT was a protective factor for DMFS (HR, 0.145; 95% CI, 0.043–0.488; P = 0.002) in stage III disease; however, it could adversely affected DFS (HR, 2.009; 95% CI, 1.316–3.065; P = 0.001), OS (HR, 1.671; 95% CI, 1.060–2.636; P = 0.027) and DMFS (HR, 1.986; 95% CI, 1.155–3.416; P = 0.013) in stage IVA disease. CONCLUSIONS: CCRT-AC may be a more effective treatment modality in patients with stage IVA NPC disease, while IC-CCRT was superior in stage III disease.