DA-R-EPOCH May Mitigate the Adverse Prognostic Implication of the Diagnosis-to-Treatment Interval (DTI) in Large B-Cell Lymphomas.

Background: Short diagnosis-to-treatment interval (DTI) is associated with high-risk disease and poor survival in diffuse large B-cell lymphoma (DLBCL). There is a paucity of literature on DTI and survival in DLBCL treated with first-line DA-R-EPOCH. We hypothesized that rapid initiation of DA-R-EPOCH in aggressive and high-risk DLBCL mitigates the adverse prognostic implication of short DTI.

Patients and methods: We retrospectively examined the association of DTI, categorically (short DTI ≤ 14 and long > 14 days) and continuously, with clinical features and survival outcomes in DLBCL treated with first-line DA-R-EPOCH at our institution.

Results: A total 190 patients were analyzed, 21% with high-grade DLBCL subtypes, 56% IPI ≥ 3, and median DTI of 13 days. The short DTI cohort contained more patients with IPI ≥ 3, bulky disease, and elevated LDH. When analyzed categorically and continuously, DTI was not associated with significant differences in PFS or OS. There was significant multivariable interaction between bulky disease, DTI, and PFS (P = .033), with improved PFS in patients with bulky disease in the short DTI cohort.

Conclusion: We found that negative prognostic implications of DTI are mitigated in DLBCL patients treated with first-line DA-R-EPOCH, suggesting that urgent initiation of DA-R-EPOCH in high-risk DLBCL, including bulky disease, may improve survival. Our study's shorter DTI compared with DTIs reported in prospective DLBCL trials highlights DTI as a marker of external validity in clinical trial results. Future trials should implement protocols encouraging shorter, realistic DTIs to avoid selection bias against high-risk patients who are unable to delay treatment.