Relative Dose Intensity and Pathologic Response Rates in Patients With Breast Cancer and With and Without HIV Who Received Neoadjuvant Chemotherapy

Abstract

PURPOSEPatients who are HIV-positive and have breast cancer have worse overall survival (OS) compared with patients who are HIV-negative. Pathologic complete response (pCR) and relative dose intensity (RDI) of chemotherapy are associated with survival. We assessed whether pCR and RDI rates were lower for patients who are HIV-positive and received neoadjuvant chemotherapy (NACT).METHODSThis was a prospective cohort analysis of patients initiating NACT in Botswana (February 2017 to September 2019). Primary outcomes were pCR and RDI; secondary outcomes were OS and toxicity. HIV status and zidovudine (ZDV) treatment were stratification factors. Multivariable analysis was used to control for confounding.RESULTSIn total, 26 of 110 enrolled individuals were HIV-positive. In univariable analysis, HIV-positive (odds ratio [OR] = 0.2; P = .048) and RDI < 0.85 (OR = 0.30; P = .025) were associated with pCR. In multivariable analysis, the magnitude of association decreased for HIV-positive (OR = 0.28; P = .11), but RDI < 0.85 remained independently associated with pCR (OR = 0.32; P = .035). Patients who are HIV-positive had significantly lower mean RDI, and those on ZDV had significantly lower RDI. Ninety-one (83%) were stage III with 2-year OS significantly worse for patients who are HIV-positive (58% v 74%). Hazard ratio for all-cause mortality was 2.68 (95% CI, 1.17 to 6.13; P = .028) in patients who are HIV-positive compared with patients who are HIV-negative. Toxicity rates were similar despite patients who are HIV-positive receiving significantly lower dose intensity chemotherapy.CONCLUSIONPatients who are HIV-positive and have breast cancer in Botswana have lower pCR rates and also receive lower dose intensity therapy, which may contribute to worse OS. Patients who are HIV-positive on ZDV-containing regimens received even lower dose intensity of NACT. Administering optimal dose intensity in patients who are HIV-positive remains a challenge, and targeted interventions that address modifiable risk factors are needed to improve therapy delivery and outcomes.