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 %; = 0.014) and OS (87.6% vs. 87.0%; = 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; = 0.009) and OS (HR, 1.487; 95% CI, 1.035-2.136; = 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; = 0.001), OS (HR, 1.671; 95% CI, 1.060-2.636; = 0.027) and DMFS (HR, 1.986; 95% CI, 1.155-3.416; = 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.