32 Impact of Comorbid HIV Infection on Breast Cancer Time to Treatment and Chemotherapy Relative Dose Intensity

Background/Significance

Patients with breast cancer (BC) living with comorbid HIV (BCLWH) have poorer survival than patients with BC without HIV. Delayed time of treatment initiation (TTI) after BC diagnosis and reduced adjuvant chemotherapy relative dose intensity (RDI) both increase BC mortality. We aim to understand whether patients with BC with and without comorbid HIV experience differences in receipt of timely and complete BC treatment, which could contribute to survival disparities.

Materials and Methods

We used diagnostic codes from 2 centers to identify a cohort of women with stage I to III BC diagnosed between January 1, 2000, and December 31, 2018, and concurrent HIV infection. Tumor registry data were then used to identify a control cohort of patients with BC without HIV, with 2 controls matched by institution, BC stage, and year of diagnosis for each patient with BC living with HIV. Our primary end point was TTI after BC diagnosis. For patients who received neoadjuvant or adjuvant chemotherapy, we also measured RDI. We used a Cox proportional hazards model to compare TTI and a linear regression model to compare RDI.

Results

We identified 38 patients with BCLWH and matched 76 women with BC alone. They differed by race/ethnicity, relationship status, and estrogen receptor (ER) status, but had similar stage, HER2 status, and BC grade. Median TTI was 50 days (interquartile range IQR, 35-68) for patients with BCLWH and 44.5 days (IQR, 36-59.5) for control patients (HR adjusted for ER, race, and relationship status, 0.85; 95% CI, 0.58-1.56). Median chemotherapy RDI was 0.92 (IQR, 0.86-0.96) in 22 patients with BCLWH and 0.98 (IQR, 0.92-1.00) in 43 control patients (adjusted P = .008).

Conclusions

RDI was lower in patients with BCLWH; TTI was not significantly different. RDI differences do not entirely explain survival disparities in patient with BC living with HIV but may point to further differences in treatment quality. Future work will explore whether patients with BCLWH experience increased chemotherapy toxicity or if social determinants limit chemotherapy access.

Author Affiliations:

Elizabeth Rubin,¹ Philippos Costa,¹ Michael H. Antoni,² Judith Hurley, MD¹ Gilberto Lopes, MD¹ Danial S O’Neil¹

¹Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL

²Department of Psychology, University of Miami, Miami, FL