Background: Splenic marginal zone lymphoma (SMZL) is a rare indolent lymphoma with extremely limited population-level evidence on social and treatment correlates of survival. Methods: We conducted a retrospective cohort study using SEER (2000 to 2022) to evaluate OS in primary SMZL (ICD O 3 9689; spleen C42.2). We summarized baseline features and treatments and used Kaplan–Meier and Cox regression. Results: The cohort included 3548 patients (mean age: 68.2 years; 53.6% female). Most were White (89.8%) and non-Hispanic (92.1%). The Ann Arbor stage was missing in 39.4%. Treatment included systemic antineoplastic therapy in 26.4%, beam radiation in 0.7%, and primary site surgery in 21.4%. At last follow-up, 56.8% were alive; non-Hodgkin lymphoma accounted for 15.8% deaths in the cohort, with substantial competing causes including heart disease (6.1%). In multivariable Cox analysis, OS was independently associated with age (HR 1.082 per year, 95% CI 1.072–1.091), male sex (HR 1.34, 95% CI 1.14–1.57), Hispanic ethnicity (HR 1.42, 95% CI 1.08–1.88), systemic antineoplastic therapy (HR 1.42, 95% CI 1.18–1.70), divorced/separated marital status vs. married (HR 1.35, 95% CI 1.03–1.77), and stage IV disease (HR 1.70, 95% CI 1.16–2.50). Race and year of diagnosis were not independently associated with OS in the adjusted model. Conclusions: In our large population-based analysis, OS in SMZL tracks with demographic and social variables and competing risks. Stage missingness and treatment selection limit causal inference for management effects.
Pustake et al. (Mon,) studied this question.