Efficacy and outcomes of systemic chemotherapy in posttransplant and immunosuppression associated Kaposi sarcoma: Twenty years experience of a tertiary cancer center.

Kaposi sarcoma is a malignant angioproliferative disease, and human herpesvirus-8 plays a major role in its etiology. Iatrogenic Kaposi sarcoma (IKS) can occur in patients undergoing immunosuppressive therapy. The treatment strategy for patients with IKS is immunosuppressive therapy modification. However, it is unclear which chemotherapy drug is the most effective and safe in the treatment of IKS. Therefore, we investigated the efficacy and safety of systemic treatment in patients with IKS at our tertiary cancer center. This cross-sectional retrospective study analyzed the clinical data of 22 patients diagnosed with IKS between January 2000 and January 2020. The patients were divided into the following 2 groups according to the transplantation status: organ transplant recipient (OTR) group and non-organ transplant recipient (non-OTR) group. Of the 22 patients, 12 were included in the OTR group and 10 were included in the non-OTR group. The median patient age at diagnosis was 52.1 years in the OTR group and 68.1 years in the non-OTR group. The median overall survival (OS) was 65.4 months in the OTR group, while the median OS was not reached in the non-OTR group. There was no statistically significant difference in OS between the 2 groups (P = .45). The 5-year OS rate among all patients was 54%. In the OTR group, the objective response rate and disease control rate were 50% and 83%, respectively, and in the non-OTR group, the objective response rate and disease control rate were 60% and 90%, respectively. Chemotherapy was well tolerated in both groups. Hematological toxicities were the main dose-limiting adverse events. Grade III/IV leucopenia and neutropenia were observed in 5 and 4 patients, respectively; however, no patient experienced febrile neutropenia. No chemotherapy-related death occurred. Systemic chemotherapy is an effective treatment and can be considered for disease control in patients with an aggressive disease course, who do not experience regression with immunosuppressive therapy modification.