Evaluating intralesional bleomycin for Kaposi sarcoma: A retrospective study

Summary: This study evaluates the efficacy of intralesional (IL) bleomycin for treating Kaposi sarcoma (KS) and examines treatment response based on HIV/AIDS status. A retrospective cohort study was conducted on 20 patients (14 with HIV/AIDS and 6 without HIV/AIDS) treated with IL bleomycin at Northwestern Medicine. The final analysis included 95 lesions (58 from patients with HIV/AIDS and 37 lesions from patients without HIV/AIDS). Univariable logistic and Cox regression models identified predictors of complete resolution (CR) and time to CR. Papulonodular lesions were the predominant morphology (65.5%). 44.9% of lesions were ≤0.5 cm and 24.5% were 0.6-1.0 cm, with a median size of 0.5 cm (range: 0.1-3.0 cm). Lesion size did not significantly differ by HIV/AIDS status (p=0.102). CR was achieved in 63.6% of all lesions, with 74.1% resolving in patients with HIV/AIDS and 51.4% in patients without HIV/AIDS (p=0.622). Lesions in patients with HIV/AIDS took longer to reach CR, though this difference was not statistically significant (Median: 97.0 vs. 69.5 days, p=0.419). Lesion size was not significantly associated with CR or time to CR. Papulonodular lesions correlated with a shorter time to CR in the total cohort (HR: 4.68, 95% CI: 2.42-9.03, p<0.001). Lesions on the foot, ankle, or heel resolved faster in the total cohort (HR: 3.99, 95% CI: 2.12-7.5, p<0.001) and the HIV/AIDS-positive subgroup (HR: 6.0, 95% CI: 2.66-13.53, p<0.001). Lesions on the leg, hip, or buttock were associated with a longer time to CR for all lesions and both subgroups (All lesions: HR: 0.15, 95% CI: 0.08-0.31, p<0.001). Our findings support the use of IL bleomycin for KS, particularly for papulonodular lesions and those on the foot, ankle, or heel while highlighting a similar treatment timeline to CR in both HIV/AIDS-positive and negative patients. Further large-scale studies are warranted to optimize treatment protocols, revise relevant treatment guidelines, and inform patient counseling and expectations. Sukul Mittal¹, Elissa Goorman¹, Cecile Schreidah¹, Cuong Nguyen¹, Jennifer Choi¹, Lida Zheng¹ 1. Northwestern University Feinberg School of Medicine, Chicago, IL, United States. Clinical Research: Interventional Research