Association between time from diagnosis to treatment and survival of patients with nasopharyngeal carcinoma: A population-based cohort study.

BACKGROUND: Treatment delays have frequently been observed in cancer patients. Whether the treatment delays would impair the survival of patients with nasopharyngeal carcinoma (NPC) is still unclear. METHODS: The data were derived from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. Patients were divided into groups of timely treatment (<1 month), intermediate delay (1 and 2 months), and long delay (3-6 months). The influence of different treatment delay intervals on long-term survival was evaluated by multivariate Cox regression analysis. RESULTS: In total, 2,048 patients with NPC were included in our study. There were 551 patients in the early stage (I, II stage: 26.9 %) and 1,497 patients in the advanced stage (III, IV stage: 73.1 %). No significant difference in overall survival (OS) or cancer-specific survival (CSS) was observed among the groups with various treatment delay intervals (p = 0.48 in OS and p = 0.43 in CSS, respectively). However, upon adjusting for covariates, a significantly improved OS probability emerged in patients with intermediate treatment delays compared to those who received timely interventions in both the entire study population ((adjusted)Hazard Ratio ((a)HR)=0.86, 95 % CI: 0.74-0.99, p = 0.043) and the subgroup with advanced stage ((a)HR=0.85, 95 % CI: 0.72-1.00, p = 0.049). Regarding the CSS probability, similar associations were also observed in the entire study population ((a)HR=0.84, 95 % CI: 0.71-0.98, p = 0.030) as well as the advanced-stage patients ((a)HR=0.83, 95 % CI: 0.70-0.99, p = 0.038). CONCLUSIONS: Our results revealed that treatment delays are not associated with worse survival of NPC patients. Tumor-specific characteristics and subsequent treatment modalities play more pivotal roles in the prognosis of NPC.