Impact of Differences in Time from Diagnosis to Treatment on DLBCL Response and Survival Outcomes: A VA Study

Introduction With an incidence of 5.6 per 100,000 per year, diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (Teras, 2016) and has a 5-year relative survival of 63.8% (SEER Statistics, 2018). While there is not currently a universally accepted timeline for initiation of therapy in DLBCL, retrospective studies have demonstrated that delays in initiation of treatment can lead to adverse outcomes in DLBCL, such as decreased overall survival (Phipps, 2018). We performed a retrospective review of Veterans Affairs (VA) patients nationwide to assess how frequently delays occurred in treatment initiation and we analyzed the impact of time to treatment on response rates to first-line chemotherapy and on survival outcomes. Methods We performed a retrospective chart review of 2036 randomly selected records of patients seen within the VA nationwide who were diagnosed with lymphoma between 1/1/2011 and 12/31/2017. We included patients diagnosed with DLBCL. We excluded other types of lymphoma, patients whose workup and treatment were outside of the VA system, and patients with primary central nervous system (CNS) lymphoma. We determined the time from diagnosis to treatment (TDT), defined as the number of days from the date of pathology results to the date of initiation of treatment for each patient, and divided these into two-week blocks. The Wilcoxon-Mann-Whitney test was used to compare median overall survival between the groups. Results 971 patients were included in the study. Patients were predominantly male (96.2%), with a median age of 67 (Table 1). The median TDT was 20 days. Those with TDT of 0-14 days, 15-28 days, 29-42 days, and 43+ days had an objective response rate (ORR) of 70.9%, 84.5%, 82.9%, and 77.6%, respectively (Table 2). The same groups had a 2-year overall survival (OS) rate of 61.6%, 77.6%, 80.7%, and 72.7%, respectively. They demonstrated median OS of 36.1 months, 46.9 months, 46.4 months, and 47.1 months, respectively. The 2-year OS rates were significantly lower for the 0-14 day group compared to the 15-28 days group (P = 0.0001), 29-42 group (P