Clinical features, outcomes, and prognostic factors of lymphocyte-depleted classical Hodgkin lymphoma: a population-based SEER analysis.

Lymphocyte-depleted classical Hodgkin lymphoma (LD-cHL) is a rare histologic subtype of classical Hodgkin lymphoma. This population-based study aimed to describe the clinical characteristics and prognostic factors of LD-cHL using data from the SEER registry.LD-cHL patients were older (median age 55 years, IQR: 37-72) than those with other subtypes (median age 38 years, IQR: 25-58; p < 0.001). They were more likely to present with advanced disease (35% Stage IV [N = 159] vs. 15% [N = 6,136]; p < 0.001). B symptoms were also more frequent in LD-cHL (67.8%, N = 307 vs. 54.5%, N = 23,025; p < 0.001).The 5-year overall survival rate for LD-cHL was 51.2% (95% CI: 46.7-56.2), lower than the 81.1% (95% CI: 80.7-81.5) observed in other subtypes. Random survival forest analysis identified age (variable importance: 0.31) and chemotherapy receipt (0.10) as the variables with the highest importance scores. Age stratification showed 5-year overall survival rates of 78.5% (95% CI: 72.5-85.1) for patients < 40 years, 43.3% (95% CI: 36.4-51.6) for those aged 40-60 years, and 15.6% (95% CI: 9.6-25.2) for those > 60 years. Chemotherapy receipt was associated with higher survival rates across all age groups.In subgroup analyses limited to patients who received chemotherapy, LD-cHL remained associated with inferior survival compared with other subtypes. Lymphoma-specific survival analysis yielded 5-year rates of 88.9%, 84.3%, and 60.5% in the < 40, 40-60, and > 60 years groups, respectively.This study confirms that LD-cHL is associated with older age, advanced stage at presentation, and relatively poor survival in real-world settings. Further studies with central pathological review and more detailed clinical data are needed to improve the understanding and management of this rare subtype.