Prognostic factors and survival in HHV8 positive diffuse large B cell lymphoma: a national cancer database analysis.

HHV8-positive diffuse large B-cell lymphoma (HHV8+ DLBCL) is a rare and aggressive lymphoma frequently associated with multicentric Castleman disease. Population-based data remain limited. Using the National Cancer Database (2004-2023), we analyzed 262 patients with histologically confirmed HHV8+ DLBCL (ICD-O-3 9738/3), representing the largest cohort to date. The cohort was predominantly male (76.7%), White (66.0%), with a mean age of 52.6 years. The primary site was nodal in 78.6%. Systemic therapy was administered in 72.9% of patients. Median overall survival was 133 months, with 1-, 3-, and 5-year survival rates of 68.2%, 63.1%, and 59.9%, respectively. On multivariable Cox regression, age ≥60 years, Charlson-Deyo score ≥1, HIV-positive status, and lack of systemic therapy and surgery to the primary site were independently associated with worse overall survival. In a subgroup analysis restricted to patients with known HIV status (n = 113), HIV-positive status was the only variable significantly associated with worse overall survival on univariable analysis.