Impact of diagnosis to treatment interval on outcomes in patients with newly diagnosed marginal zone lymphoma - a US multisite study.

Diagnosis-to-treatment interval (DTI) is an important prognostic factor in patients with newly diagnosed aggressive lymphomas, however the impact of DTI on outcomes in marginal zone lymphoma (MZL) is unknown. In this multicenter retrospective cohort study, we included adult patients with MZL who received first-line immunochemotherapy within 120 days of diagnosis at 10 US medical centers. Patients who received treatment within 60 days from their diagnosis were classified into the short DTI group and those who received treatment beyond 60 days into long DTI group. The primary objective was progression-free survival (PFS), while secondary objectives included overall survival (OS) and cumulative incidence of histologic transformation (HT) between the two groups. Of the 870 patients with newly diagnosed MZL, 177 patients met the inclusion criteria and were included in this analysis. Among these 144 (81%) were in the short DTI group and 33 (19%) in the long DTI group. In the univariable analysis, presence of B symptoms was associated with short DTI and remained significantly associated with short DTI in the multivariable analysis (OR = 11.91, p = 0.017). Short DTI was not associated with a statistically different PFS or OS compared to long DTI in the univariable or in multivariable analysis. The cumulative incidence of HT was not significantly different between the two groups. This is the first study to-date to report on the association of DTI on outcomes in MZL patients. This lack of prognostic utility of DTI in newly diagnosed MZL, in contrast to aggressive B-cell lymphomas, may be intrinsically linked to the underlying disease biology.