Provider Insights and Utilization of Psychiatric Pharmacogenomics for Patients With Comorbid Breast Cancer and Emotional Distress

**Background
**Patients with breast cancer frequently experience anxiety and depression, yet systemic delays in psychiatric care often leave oncologists to manage these conditions. The recent adoption of DPYD genotyping into NCCN guidelines for fluoropyrimidine safety marks a shift toward routine pharmacogenomic (PGx) integrations in oncology. This creates an opportunity to expand PGx to supportive care, specifically for psychiatric comorbidities. While Clinical Pharmacogenetics Implementation Consortium (CPIC) Level A guidelines exist for selective serotonin reuptake inhibitors (SSRIs), little is known about how oncology providers apply psychiatric PGx. This study examines provider perspectives on the utility and clinical decision-making implications of psychiatric PGx testing for patients with comorbid breast cancer and emotional distress.

**Methods
**Breast oncology providers attended an educational seminar focused on the clinical application of PGx guidelines and a 13-gene neuropsychiatric panel (Tempus nP). Knowledge, attitude, and utilization of PGx tests were assessed at baseline (after the seminar). Surveys were also conducted following receipt of each subsequently ordered test for the impact of PGx testing on medication selection. Phenotypic findings from the PGx test reports were also summarized.

Results
To date, 11 breast oncology providers (Female = 9, Male = 2; Years in practice = 12.3 ± 10.1) across two centers have enrolled. At baseline, most providers (n = 7, 64%) strongly agreed that PGx provides value in psychiatric medication selection, yet only (n = 3/10, 30%) strongly agreed that they were confident in their ability to understand PGx results independently. Across 25 post-test surveys, 96 % (n = 24) reported that PGx testing had at least a mild impact (increased confidence in medication choice), with 24% (n = 6) of those responses reporting substantial impact (a change in prescribed medication selection or dose). Phenotypic analysis of 35 PGx tests revealed the majority (n = 31, 89%) of patients possessed a non- normal result for CYP2D6, CYP2C19, or SLC6A4 gene, which are commonly involved in response to first-line SSRIs.

Conclusions
These early findings indicate that many breast oncology providers report value in using PGx results to increase their confidence in psychiatric medication management, and genomic results highlight that variations in genes that impact response and side effect burden for first line antidepressants are common among individuals with breast cancer experiencing emotional distress. Ongoing data collection will further assess attitudes and perspectives on how psychiatric PGx can affect oncology provider medication decision-making and explore relationships between providers attitudes and genomic results.