Sociodemographic Factors and Treatment Patterns Associated with Overall Survival in Splenic Marginal Zone Lymphoma: A Nationwide Retrospective Cohort Study (2000-2022).

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.