Impact of diagnosis-to-treatment interval in relapsed or refractory diffuse large B-cell lymphoma

The diagnosis-to-treatment interval (DTI) has been identified as a prognostic factor in newly diagnosed diffuse large B-cell lymphoma (DLBCL). However, its significance in relapsed or refractory DLBCL (R/R DLBCL) remains unclear. This study aimed to investigate the impact of DTI on survival outcomes in patients with R/R DLBCL. We reviewed the medical records of patients with R/R DLBCL who received second-line therapy. DTI at relapse or refractory disease (r/r DTI) was defined as the time from radiological diagnosis-to-treatment initiation, with a cut-off of 28 days. The primary endpoint was overall survival (OS). A total of 184 patients with R/R DLBCL were included. Patients with short r/r DTI had significantly worse OS than those with long r/r DTI (1-year OS: 50.4% vs. 79.5%; P < 0.001). Short r/r DTI was associated with adverse clinical features, including poor performance status, elevated lactate dehydrogenase levels, and high International Prognostic Index at relapse. Multivariate analysis demonstrated that short r/r DTI was independently associated with significantly inferior OS (HR 1.77; P = 0.043). In conclusion, DTI is an independent prognostic factor in R/R DLBCL and can be considered in patient selection for clinical trials.