Time Trend Analysis of Splenectomy for Splenic Marginal Zone Lymphoma: Declining Surgery, Promising Survival

The purpose of current study was to examine the incidence, characteristics, treatment, and survival of splenic marginal zone lymphoma (SMZL).

Using SEER-18 database, patients diagnosed with SMZL between 2000 and 2018 were included. Effect of splenectomy on survival was evaluated after balancing the confounding factors by propensity score matching. Rates of splenectomy and 1-year relative survival were calculated for each year. A logistic regression model identified factors related to splenectomy, and a Cox regression model assessed factors linked to overall survival (OS).

A total of 2790 patients with SMZL were analyzed. The majority were older than 60 years, female, and white. The age-adjusted incidence of SMZL was 0.17/100,000 person-years, with higher incidence in males. Incidence increased by 0.68%/year and peaked at 80-84 years for both genders. The SMZL-specific survival rates at 3 and 5 years were 89.6% and 85.3%, respectively. Meanwhile, the relative survival rates for the same periods were 88.6% and 85.9%, respectively. Splenectomy patients were more likely to be younger, male, and diagnosed with early-stage disease. Despite the decreasing utilization rate of splenectomy from 59.4% in 2000 to 16.2% in 2018, the 1-year relative survival rate remained relatively stable with minor fluctuations over time. Whether or not the patient underwent splenectomy was not found to be a significant prognostic indicator for OS.

Our study demonstrated a decreasing use of splenectomy but a relatively stable survival in patients with SMZL, highlighting the urgency to better understand the role of splenectomy and its associated outcomes.