Kaposi's sarcoma in kidney transplant recipients: a 23-year experience.

BACKGROUND: Kaposi's sarcoma (KS) is a relatively common malignancy after kidney transplantation, accounting for up to 80% of all malignancies in developing countries. AIM: To assess the frequency of KS in renal transplant recipients, and determine the impact of demographic factors, immunosuppression and treatment options.
DESIGN: Retrospective study in a single centre in South Africa.
METHODS: Charts and pathology reports of 542 recipients of 623 kidney allografts treated at our institution between 1976 and 1999 were reviewed.
RESULTS: After a mean follow-up of 6.4 years, 21 (3.9%) recipients had KS, representing 47.7% of all post-transplant malignancies. KS accounted for more post-transplant cancers in non-White than White patients (79.1% vs. 11.7%, p < 0.001). KS was equally common in males and females, and was not more frequent under cyclosporine. Skin involvement was universal; visceral disease occurred in six patients (28.6%). Sixteen (94.1%) patients with limited skin disease and two (100%) with superficial nodal disease responded to withdrawal or reduction of immunosuppression. Renal function was preserved when immunosuppression was reduced instead of withdrawn (p = 0.02). Patients with vital organ involvement succumbed rapidly to KS. Post-mortem examination revealed more extensive disease than was suspected clinically. DISCUSSION: Ethnic differences exist in the frequency of KS in patients residing in the same geographical area. Since withdrawal results in graft loss, reducing immunosuppression should be first-line treatment for patients with disease limited to skin, and possibly for disease of the superficial lymph nodes. The malignant behaviour of KS, and extent of pathological involvement, cast doubt on the idea that KS is a hyperplasia rather than a true malignancy.