Kaposi sarcoma risk persists despite advances in HIV treatment

South African men and women with HIV, as well as HIV–positive men who have sex with men on several continents, remained at increased risk for Kaposi sarcoma despite declining incidence of the disease due to ART, according to recently published findings.

“People infected with HIV are at high risk of developing Kaposi sarcoma,” Julia Bohlius, MD, of the University of Bern, Switzerland, and colleagues wrote. “[Kaposi sarcoma] incidence rates seem to be higher in adults who initiated ART in sub-Saharan Africa and the U.S. than in Europe. However, direct comparisons of [Kaposi sarcoma] incidence rates across studies are complicated by differences in study populations and designs.”

Bohlius and colleagues examined data from two large international HIV cohorts to identify 208,140 adults who had begun ART after 1995. Patients came from 57 countries across several regions around the world: Asia-Pacific, South Africa, Europe, Latin America and North America.

The researchers reported that the Asia-Pacific region had a significantly lower incidence of Kaposi sarcoma compared with the other regions: 52 per 100,000 person-years, compared with a range of 180 to 280 cases per 100,000 person-years in all other regions.

South African women faced a fivefold greater risk for Kaposi sarcoma (adjusted HR = 4.56; 95% CI, 2.73-7.62), whereas South African men were at a twofold greater risk (HR = 2.21; 95% CI, 1.34-3.63) compared with European patients, Bohlius and colleagues wrote. In North America, Latin America and Europe, meanwhile, MSM faced a sixfold greater risk for Kaposi sarcoma than women (HR = 5.95; 95% CI, 5.09-6.96).

South African patients with CD4 counts of 700/µL or greater faced only half as much risk as those with CD4 counts of less than 50/µL (HR = 0.53; 95% CI, 0.17-1.63); however, the risk was reduced by 95% or greater in other parts of the world, according to Bohlius and colleagues.

Researchers suggested that the increased risk in South African patients may be a result of a higher incidence of coinfection with human herpesvirus-8 (HHV-8) compared with other regions.

“While a vaccine against HHV-8 remains unavailable, early ART initiation and maintaining high CD4 cell counts are essential to reduce [Kaposi sarcoma] incidence in populations at high risk for [herpes virus 8] coinfection.” – by Andy Polhamus

 

Disclosure: Bohlius reports no relevant financial disclosures. Please see the full study for a complete list of all other researchers’ relevant financial disclosures.