62 The Impact of Genomic Assays on Breast Cancer Systemic Therapy Treatment Decisions in a Mostly Black Patient Population

62 The Impact of Genomic Assays on Breast Cancer Systemic Therapy Treatment Decisions in a Mostly Black Patient Population

Background

Multiple genomic assays are currently available for assessing breast cancer’s (BC) prognostic and predictive outcomes. Two of the widely utilized assays are the 21-gene recurrence score, (Oncotype DX [ODX]), and the 70-gene signature test (MammaPrint [MP]). ODX characterizes the results based on a 1-100 scale with a score of ≥ 26 considered a high recurrence score (OHR) and a score of < 26 a low to intermediate recurrence score (OLR). MP classifies the results as either high (MHR) or low risk (MLR). The results of these assays help guide clinicians’ treatment of BC. Studies examining the impact of these assays on systemic therapy treatment decisions in Black and minority patients are limited.

Methods

We examined the results of the 2 genomic assays in our community-based Comprehensive Breast Center with a predominantly Black patient population. This was a retrospective institutional review board (IRB)-approved analysis of a total of 88 patients who underwent genomic testing with MP on core needle biopsy from 2021 to 2023. Twenty-five of these patients had ODX testing in addition to MP, this time on the surgical specimen. Chemotherapy treatment decisions were determined.

Results

Of the 88 patients, 85 (96.6%) were female and 3 (3.4%) were male. Eighty-five (96.6%) of the patients were Black/African American, 3 (3.4%) were Hispanic. Fifty-two (59.1%) of the patients were found to have MHR and 36 (40.9%) had MLR. Out of the 52 who had MHR, 45 (86.5%) were offered chemotherapy. Twenty-five of these patients received chemotherapy in the neoadjuvant setting (NAC) and 17 patients received adjuvant chemotherapy (AC). A total of 3 patients were offered chemotherapy but declined. Out of the 36 MLR patients, 3 patients received NAC, 5 patients received AC, and 2 patients were offered chemotherapy but declined. Out of the 25 patients who also had ODX, 22 (88.0%) were found to have OLR and 3 (12.0%) had OHR. Three patients had both MHR and OHR, all 3 (100%) were offered chemotherapy. Eleven patients had MHR, but OLR, 7 (63.6%) of these patients were offered chemotherapy. Eleven patients had MLR and OLR; 1 (9.1%) of these patients was offered chemotherapy.

Conclusions

In our mostly Black patient population, patients were more likely to be offered chemotherapy if they had an MHR result (P< .001). Patients were also more likely to receive NAC if they had an MHR score (P< .001). Additionally, there was a notable discordance between MP and ODX as 11 of 25 patients with both assays were found to have MHR, but not OLR. These patients were more likely to be offered chemotherapy than not.