Abstract:
In resource- limited areas, such as sub-Saharan Africa, problems in accurate
cancer case ascertainment and enumeration of the at-risk population make it
difficult to estimate cancer incidence. We took advantage of a large well-
enumerated healthcare system to estimate the incidence of Kaposi sarcoma (KS),
a cancer which has become prominent in the HIV era and whose incidence
may be changing with the rollout of antiretroviral therapy (ART). To achieve
this, we evaluated HIV-infected adults receiving care between 2007 and 2012
at any of three medical centers in Kenya and Uganda that participate in the
East Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA)
Consortium. Through IeDEA, clinicians received training in KS recognition and
biopsy equipment. We found that the overall prevalence of KS among 102,945
HIV- infected adults upon clinic enrollment was 1.4%; it declined over time at
the largest site. Among 140,552 patients followed for 319,632 person-years, the
age- standardized incidence rate was 334/100,000 person-years (95% CI: 314–
354/100,000 person- years). Incidence decreased over time and was lower in
women, persons on ART, and those with higher CD4 counts. The incidence
rate among patients on ART with a CD4 count >350 cells/mm3 was 32/100,000
person-years (95% CI: 14–70/100,000 person-years). Despite reductions over
time coincident with the expansion of ART, KS incidence among HIV-infected
adults in East Africa equals or exceeds the most common cancers in resource-
replete settings. In resource- limited settings, strategic efforts to improve cancer
diagnosis in combination with already well-enumerated at-risk denominators
can make healthcare systems attractive platforms for estimating cancer
incidence.
