37 Treatment Outcomes Using Neoadjuvant Chemotherapy for HER2-Positive Breast Cancer in African American and Hispanic Women

¹Trinitas Comprehensive Cancer Center, Elizabeth, NJ.

²Trinitas Regional Medical Center, Elizabeth, NJ.

Background

In the United States, African American (AA) and Hispanic (H) women have a 20% lower incidence of breast cancer than White women. Despite this lower incidence, breast cancer continues to be the leading cancer diagnosis and cause for mortality in this population. Factors such as socioeconomic status, lack of access to health care, and genetics may be risk factors for this select group. HER2-positive disease in the minority population has not been well described. The aim of this study is to further characterize this disease and to determine the effects of neoadjuvant treatment within this population.

Materials and Methods

This study reports on 37 women with HER2-positive, nonmetastatic disease diagnosed from 2015 to 2019 in a single-institution, community program serving a minority-dense population. Our data were compiled using our facility’s cancer registry in Excel format. The patient (pt) sample included 55% H, 33% AA, and 10% Caucasian women; 2% of women identified with other racial groups. AA and H pts made up 88% of our HER2-positive pts. Of the total pts, 55% (n = 20) met criteria to receive neoadjuvant chemotherapy (NAC), which included trastuzumab (Herceptin) alone or with pertuzumab (Perjeta).

Results

In our study, we noted that all NAC pts had an overall complete response rate (CRR) of 48% and a partial response rate (PRR) of 52%. H pts had a 55% PRR and a 45% CRR while AA pts had a 71% PRR and a 29% CRR. H pts were found to have significantly more sentinel lymph node dissections (88%) performed vs axillary lymph node dissections (16%) following NAC, suggesting improved axillary response. AA women were found to have a greater reduction in breast tumor size, which led to 71% partial mastectomies compared with 29% modified radical mastectomies.

Conclusions

NAC therapy has become the standard of care for those with HER2-positive disease. Most studies using NAC have noted responses in predominantly White women. Very few studies have delineated responses in H and AA women. Here we see a possible benefit of NAC in improving axillary disease in H women and breast disease in AA women. This is an interesting phenomenon, and a larger sample size from a multi-institutional trial that focuses on this population could confirm these findings. We should further characterize response in minority populations so we can improve treatment strategies, reduce breast cancer mortality, and ultimately improve their health outcomes.

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