The Impact of Time From Diagnosis to Initiation of Chemotherapy on Survival of Patients With Newly Diagnosed Diffuse Large B-Cell Lymphoma in the Veterans Health Administration.

Introduction: Our retrospective study evaluates the impact of time from diagnosis to treatment (TDT) on outcomes of patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) treated within the Veterans Health Administration (VHA).

Methods: VHA patients diagnosed with DLBCL between 2011 and 2019 were included, while those with primary central nervous system lymphoma were excluded. The median overall survival and progression-free survival were estimated with the Kaplan-Meier method. Univariate, bivariate, and multivariable analyses were performed using the Cox proportional hazards model. The odds ratio for refractory outcomes was calculated using logistic regression.

Results: A total of 2448 patients were included. The median time from diagnosis to treatment of the cohort was 19 days. When comparing median progression-free survival, median overall survival, and the 2-year overall survival between the group that started treatment within 1 week and each of the other groups individually, there was a significant difference favoring improved survival in all groups with a TDT longer than 1 week (P < .0001). These patients also had a lower odds ratio for refractory outcomes. On multivariable analysis, TDT remained an independent prognostic factor.

Conclusion: Our study shows that a TDT equal to or less than 1 week is associated with adverse clinical factors, worse outcomes, and response in DLBCL, even after adjusting for multiple known poor prognostic factors. This was the first time that response to first-line therapy was correlated to time to treatment. Our findings support ongoing efforts to improve currently standardized prognostic tools and the incorporation of TDT into clinical trials to avoid selection bias.