A fifth subtype of Kaposi's sarcoma, classic Kaposi's sarcoma in men who have sex with men: a cohort study in Paris.

BACKGROUND: Classic Kaposi's sarcoma (CKS) occurs predominantly among elderly men and is associated with Kaposi's sarcoma-associated herpesvirus (KSHV). In low-endemic countries, KSHV infects predominantly men having sex with men (MSM).

OBJECTIVES: To describe a cohort of classic Kaposi sarcoma in a low-endemic area for KSHV, to highlight the features of CKS in MSM and identify prognostic factors.

METHODS: Retrospective single-centre study of CKS cases. We compared MSM to heterosexual patients. Then, we divided the patients into two subgroups, those requiring a systemic treatment and the others, and we performed univariate and multivariate analyses to determine aggressiveness of CKS.

RESULTS: Between 2006 and 2015, seventy-four patients were included. Mean age at diagnosis was 68.9 years; sex ratio (M/F) was 6.4, and 28% were MSM; MSM patients were younger (P = 0.02), less often originated from endemic areas (P < 0.0001). KS was less severe (P = 0.04), required more often a local treatment than a systemic one (P = 0.03). On multivariate analysis, CD4 T-cell count > 500/mm3 at baseline was associated with a reduced risk of severe evolution.

CONCLUSION: First CKS cohort in low-endemic zone. We describe a fifth subtype of KS: KS in MSM. The CD4 T-cell count was found to correlate with prognosis.