Clinicopathologic features and survival outcomes of stage IE pulmonary marginal zone lymphoma: A National Cancer Database (NCDB) analysis.

Abstract

e19076 Background: Pulmonary marginal zone lymphoma (PMZL) is a rare, indolent B-cell neoplasm and the most common form of primary pulmonary lymphoma. Its heterogeneous clinical presentation and lack of standardized tx guidelines make diagnosis and management challenging. Existing studies are limited by small sample sizes and single-institution experiences, leaving gaps in understanding its clinical features, natural history, and long-term outcomes. This study aims to comprehensively define clinicopathologic characteristics, contemporary tx patterns, and survival outcomes to inform clinical practice and guide decision-making. Methods: The NCDB Participant User File (PUF) for non-Hodgkin lymphoma was used to identify adult pts (≥18 yrs) with stage IE PMZL diagnosed between 2004–2022 using ICD-O-3 histology code 9699/3 and primary site codes C34.0–C34.9. AJCC analytic stage was used as a surrogate for early-stage disease, as Ann Arbor stage is not reliably captured. The database was used to examine clinicopathologic features and tx characteristics. Survival analysis was performed using Kaplan–Meier methods, and Cox proportional hazards models evaluated independent prognostic variables. Results: A total of 3,941 pts were included. Median age was 68 yrs (range 19–90, SD 11.9). Most pts were female (61.3%) and White (86.6%). The majority were treated at academic/research facilities (59.9%) vs community programs (38.1%). Tumors most commonly arose in lobar lung parenchyma (79.3%), with 0.9% involving the main bronchus. Charlson–Deyo score (CDS) was 0 in 67.9% and ≥1 in 32.1%. Regarding tx, 46.2% underwent surgical resection, while 53.3% had no surgery. RT was administered in 14.7%, systemic chemo in 14.6%, and immunotherapy in 14.4%. Overall, 63.0% received active tx, 18.0% were managed with active surveillance, and 17.8% were coded as unspecified tx. Median OS for the cohort was 165.4 mos (95% CI 156.0–174.8); mean OS was 153.8 mos (95% CI 148.6–159.0). Pts receiving active tx had median OS of 158.6 mos vs 122.6 mos with surveillance. Median OS was 178.5 mos for CDS=0 vs 128.8 mos for CDS ≥1. On multivariable analysis, increasing age was associated with higher mortality (HR 1.081/yr, p<0.001). Tx at academic/research programs was associated with lower mortality (HR 0.27–0.33, p=0.002–0.011). Female sex was associated with improved survival (HR 0.75, p<0.001), while CDS ≥1 increased mortality risk (HR 1.65, p<0.001). Main bronchus involvement was associated with worse outcomes (p=0.004). Surgical tx improved survival (HR 0.74, p=0.001), and immunotherapy showed a modest survival benefit (HR 1.29, p=0.036). Conclusions: Adults with stage IE PMZL exhibit indolent disease, excellent long-term survival, and favorable outcomes across tx approaches, with age, comorbidity burden, and tx facility type significantly impacting OS.