Association between the diagnosis-to-treatment interval and overall survival in Taiwanese patients with oral cavity squamous cell carcinoma

Background To investigate the association between the diagnosis-to-treatment interval (DTI) and overall survival (OS) in patients with oral cavity squamous cell carcinoma (OSCC). Methods A total of 18,677 patients with first primary OSCC identified in the Taiwanese Cancer Registry Database between 2004 and 2010 were examined. The effect of DTI on 5-year OS rates was investigated with multivariate Cox regression analysis. After the identification of the optimal cutoff for DTI based on the 5-year OS rates, DTI was classified in the following 20-day groups: ≤20 days (57% of the study patients), 21–45 days (34%), 46–90 days (6%) and ≥91 days (3%). In additional exploratory analyses, DTI was reclassified in the following 30-day interval groups: ≤30 days (81% of the study patients), 31–60 days (14%), 61–90 days (2%) and ≥91 days (3%). Results Multivariate analyses identified DTI (≤20 days versus other subgroups), sex (female versus male), age (