Overall survival and associated factors among patients with pulmonary Kaposi’s sarcoma in sub-Saharan Africa

Abstract

Visceral Kaposi's sarcoma (KS), like pulmonary KS (PKS), is more common in HIV associated/epidemic KS (EpKS). Its presentation often mimics other opportunistic pulmonary infections and is associated with poor outcomes. This study investigated the prevalence of PKS, and factors associated with overall survival at a tertiary hospital in Tanzania. This retrospective study reviewed records of 269 histologically confirmed cutaneous KS patients treated at the Ocean Road Cancer Institute between January 2019 and December 2022. Sociodemographic, clinical, and survival data were extracted from patients' files. Specialist radiologists reviewed chest radiographs taken at the time of diagnosis, categorizing them as normal, infectious infiltrates, or PKS. Data were analyzed using descriptive statistics, and Cox Proportional Hazard model identified factors linked to overall survival. Statistical significance was defined as p < 0.05. Among 269 patients with cutaneous KS, 195 had EpKS, 66 had Endemic KS (EnKS), and 8 had unknown HIV status and were excluded from further analysis. The male-to-female ratio was 2:1. While all patients had cutaneous KS lesions, 23 (8.8%) had PKS which was significantly more common in the EpKS than EnKS group (p = 0.024). Additionally, 24 patients (9.2%) had Chest X-ray findings (CXR) indicative of infection. At one year, overall survival was 53% for patients with PKS, compared with 87% for those without PKS. In the adjusted analysis, patients without PKS had an 86% lower risk of mortality than those with PKS (aHR = 0.14; 95% CI: 0.07-0.32; P < 0.001). There is high prevalence of advanced KS presentation and poor overall survival especially among PKS in SSA, despite widespread ART use. Although CXR remains the diagnostic mainstay in this setting, it is subject to notable limitations. Simple, low-cost diagnostic algorithms are needed to optimize CXR utility alongside the ongoing expansion of advanced imaging and bronchoscopic services in the region.