Impact of Time From Diagnosis to Treatment Start on the Outcomes of Patients With Nonmetastatic Anal Squamous Cell Carcinoma

Objective: To assess the impact of time from diagnosis to treatment on the survival outcomes of patients with nonmetastatic anal squamous cell carcinoma, controlling for other clinicopathological features. Methods: Surveillance, Epidemiology, and End Results research plus database was accessed, and patients with nonmetastatic anal squamous cell carcinoma were reviewed. Factors associated with longer time to treatment were evaluated through multivariable logistic regression analysis. Kaplan-Meier survival estimates were used to examine survival differences according to time to treatment (≤2 vs. >2 mo), and multivariable Cox regression analysis was used to examine factors associated with worse overall and cancer-specific survival. Results: A total of 13,032 patients were considered eligible and they were included in this study. The following factors were associated with longer time to treatment (>2 mo): male sex (odds ratio [OR]: 1.503; 95% CI, 1.292 to 1.749), and non-White race (OR for Black vs. White patients: 1.846; 95% CI, 1.488 to 2.290; OR for American Indian vs. White patients: 2.414; 95% CI, 1.197 to 4.872; OR for Asian-Pacific Islanders vs. White patients: 2.182; 95% CI, 1.440 to 3.309). Using Kaplan-Meier survival estimates, longer time to treatment was associated with worse overall survival (median OS for >2 mo=109 mo; for ≤2 mo=164 mo P<0.0001). Using multivariable Cox regression analysis, the following factors were associated with worse overall survival: older age (hazard ratio [HR]: 1.037; 95% CI, 1.034 to 1.039), male sex (HR: 1.650; 95% CI, 1.548 to 1.758), Black race (HR: 1.341; 95% CI, 1.210 to 1.487), advanced stage (HR for regional vs. localized stage: 1.596; 95% CI, 1.500 to 1.698), and longer time to treatment (HR: 1.385; 95% CI, 1.222 to 1.571). Conclusions: Time from diagnosis to treatment longer than 2 months is associated with worse survival outcomes among patients with nonmetastatic anal squamous cell carcinoma.