No abstract

Background HIV-associated Kaposi sarcoma (KS) is one of the most common malignancies in sub-Saharan Africa. The diagnosis is often based on clinical suspicion, without histopathologic confirmation. When biopsies are performed, the accuracy of interpretation by local pathologists is poorly understood. We assessed the accuracy of clinical suspicion and pathologic diagnosis of KS in two East African countries. Methods At two large HIV care sites in Uganda and Kenya, we evaluated consecutive biopsies performed from October 2008 to January 2013 upon HIV-infected adults with clinically suspected KS. Biopsies were interpreted by both local African pathologists and a group of U.S.-based dermatopathologists from a high volume medical center. For the purpose of this analysis, the U.S.-based dermatopathologist interpretation was used as the gold standard. Positive predictive value was used to characterize accuracy of local African clinical suspicion of KS, and concordance, sensitivity, and specificity were used to characterize accuracy of local pathologic diagnosis. Results Among 1106 biopsies, the positive predictive value of clinical suspicion of KS was 77% (95% CI: 74%-79%). When KS was not histopathologically diagnosed, clinically banal conditions were found in 35%, medically significant disorders which required different therapy in 59%, and life-threatening diseases in 6%. Concordance between African pathologists and U.S.-based dermatopathologists was 69% (95% CI: 66%-72%). Sensitivity and specificity of African pathologic diagnoses were 68% and 89%, respectively. Conclusions Among East African HIV-infected patients, we found suboptimal positive predictive value of clinical suspicion of KS and specific, but not sensitive, histopathologic interpretation. The findings call for abandonment of isolated clinical diagnosis of KS in the region as well as augmentation of local dermatopathologic services.

NCT01352117.

Purpose of the review Given the recent availability of antiretroviral therapy (ART) in resource-limited settings and the significant burden exacted by Kaposi’s sarcoma (KS) in these areas, we reviewed data regarding the impact of ART on KS incidence. We summarized the sizeable literature in resource-rich settings as well emerging data from resource-limited regions. Importantly, we delineated ways impact can be defined, including a) individual patient-level effectiveness; b) population-level effectiveness; c) change in population-level incidence; and d) residual risk of KS. Recent findings In resource-rich settings, there are now ample data demonstrating beneficial individual patient-level and population-level effects of ART on KS incidence. There is, however, considerable variability between studies and important methodologic shortcomings. Data from resource-limited settings are much more limited; while they preliminarily indicate individual patient-level effectiveness, they do not yet provide insight on population-level effects. Summary ART has had a substantial impact on KS incidence in resource-rich settings, but more attention is needed on validly quantifying this effect in order to determine whether additional interventions are needed. Emerging data from resource-limited regions also suggests beneficial impact of ART on KS incidence, but — given the scope of KS in these settings — more data are needed to understand the breadth and magnitude of the effect.

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.