Patients With Breast Cancer, HIV More Likely to Experience Suboptimal Adjuvant Chemotherapy Delivery

Patients with breast cancer and comorbid HIV are more likely to experience suboptimal delivery of adjuvant chemotherapy than those with breast cancer without HIV, according to a study published in JAMA Network Open.

With the introduction of antiretroviral therapy (ART), the life expectancy of US patients with HIV increased from 10.5 years in 1996 to 28.9 years in 2011. Consequently, as of 2016, 58% of patients with HIV are 45 years old or older. The researchers noted that older people with HIV are at risk for non-AIDS-defining cancers.

In particular, women living with HIV (WLHIV) are not at an increased risk of developing breast cancer, but, once they are diagnosed with it, they demonstrate significantly worse cancer-specific mortality (HR, 1.85-2.64) and overall mortality (HR, 1.85). They explained that the factors contributing to these mortality rates are unknown. Because of this, the researchers conducted a study to assess the associations between HIV infection and 2 care quality indicators: neoadjuvant and adjuvant chemotherapy relative dose intensity (RDI) and time to treatment initiation.

Limited attempts have been made to study cancer care quality among WLHIV as there are relatively few patients with both diagnoses being treated at any individual cancer center. To overcome this challenge, the researchers studied the associations between comorbid HIV and breast cancer care by pooling retrospective data from 3 large, urban cancer centers: Sylvester Comprehensive Cancer Center, Abramson Cancer Center of Penn Medicine, and the Herbert Irving Comprehensive Cancer Center.

The researchers found eligible patients by searching the electronic medical records of each cancer center for women aged 18 or older with confirmed HIV infection before or simultaneous with a diagnosis of stage I to III breast cancer from January 1, 2000, through December 31, 2018. They then created a control group by using tumor registry data to identify 2 patients with breast cancer but without HIV for every patient with HIV. From both groups, the researchers also identified a subcohort of patients who had received initial neoadjuvant or adjuvant chemotherapy for their breast cancer at the enrolling study site.

Women with breast cancer | Image credit: Vasyl - stock.adobe.com

The study population consisted of 66 women with comorbid breast cancer and HIV with 38 (57.6%) from Sylvester Comprehensive Cancer Center, 17 (25.8%) from Abramson Cancer Center of Penn Medicine, and 11 (16.7%) from Herbert Irving Comprehensive Cancer Center. Conversely, the control group consisted of 132 patients with breast cancer but without HIV.

The researchers noted that the WLHIV were slightly younger at breast cancer diagnosis than the matched controls (median age, 51.1 years [IQR, 45.7-58.2 years] vs 53.9 years [IQR, 47.0-62.5 years]). Also, a higher proportion of the WLHIV were of non-Hispanic Black race than the matched controls (65.2% vs 19.7%).

WLHIV waited a median of 48.5 days (IQR, 32.0-67.0 days) from diagnosis for their first breast cancer treatment, while those without HIV waited a median of 42.5 days (IQR, 25.0-59.0 days; unadjusted HR, 0.73; 95% CI, 0.54-0.99). Once adjusted for differences in race and ethnicity, grade, stage, receipt of primary surgery, and year of cancer diagnosis, the researchers did not significantly associate WLHIV with a longer time to breast cancer treatment initiation (HR, 0.78; 95% CI, 0.55-1.12). Despite this, non-Hispanic Black patients (HR, 0.50; 95% CI, 0.33-0.77) and Hispanic patients (HR, 0.67; 95% CI, 0.45-0.99) remained associated with treatment initiation delays.

Additionally, the chemotherapy subcohort consisted of 36 WLHIV and 62 women without HIV. The researchers discovered that fewer WLHIV were treated with a taxane than those without HIV (83.3% vs 98.4%). Also, the median overall chemotherapy RDI was lower among WLHIV (median, 0.87; IQR, 0.74-0.97) than patients without HIV (median, 0.96; IQR, 0.88-1.00; P = .01). The proportion of patients receiving an overall RDI of 0.85 or higher was also lower in WLHIV (58.3% vs 82.3%; P = .02), and grade 3 or higher neutropenia during chemotherapy happened more among WLHIV (36.1%) than those without HIV (8.6%).

The researchers acknowledged their study’s limitations, one being its small study population. Other limitations included instances of missing data and the possibility of some data errors arising from manual data extraction. They explained that these limitations occurred due to the retrospective nature of the study and the need to pool data from diverse medical record systems to study a rare population. Despite these limitations, the researchers noted that the association between HIV infection and chemotherapy tolerance reached statistical significance.

“Dose-limiting toxic effects and suboptimal receipt of neoadjuvant and adjuvant chemotherapy among patients with breast cancer living with comorbid HIV infection may contribute to this group’s well-documented increased risk of death compared with other women with breast cancer,” the authors concluded. “Coinfection with HIV may also limit the ability to safely deliver other toxic but efficacious breast cancer treatments. Strategies to better support patients with breast cancer living with HIV during toxic therapies are needed to improve outcomes among this growing population.”

Reference

O’Neil DS, Martei YM, Crew KD, et al. Time to cancer treatment and chemotherapy relative dose intensity for patients with breast cancer living with HIV. JAMA Netw Open. 2023;6(12):e2346223. doi:10.1001/jamanetworkopen.2023.46223