Tolerability of chemotherapy in HIV-infected women with breast cancer: are there prognostic implications?

Breast cancer is the most commonly diagnosed malignancy in women, but little is known about therapeutic outcomes in patients with both breast cancer and HIV. We performed a retrospective cohort study of women with or without HIV undergoing treatment for breast cancer from 1996 to 2011. Cases with HIV were 1:2 matched to non-HIV controls based on age, sex, race, and date of cancer diagnosis. Dose reduction and/or delay during chemotherapy, overall survival, and development of metastatic disease were studied outcomes. 156 (52 HIV, 104 non-HIV) subjects were analyzed. The majority of breast cancers in both groups were clinical stages 0, I, II, and III (73%). HIV infection preceded cancer diagnosis by a median of 13 years. Median CD4 count at time of cancer diagnosis was 417 cells/mcL. Approximately 87% (45/52) were on HAART, mostly protease inhibitor-based (57%) therapy. HIV-infected women needed more dose reductions and/or delays to chemotherapy due to toxicity (56% vs. 30%; p=0.03). Stage at diagnosis, triple negative receptor status, and dose reduction and/or delay were predictors of metastatic disease and death. HIV-infected women experienced more adverse events during breast cancer treatment, and a potential causative factor could be drug-drug interactions between HAART and chemotherapy.