Abstract P2-16-21: Novel use of a precision medicine tool in the neoadjuvant therapy setting

Background: Molecular genomic profiles are increasingly used to guide treatment of refractory cancers and are on the forefront of personalized medicine for select patients. The neoadjuvant chemotherapy (NAC) setting provides a meaningful opportunity to compare genomic profiles to pathologic response. We report profiles to response in a novel multi center registry. Methods: An ongoing IRB (WIRB) approved registry at 6 community breast practices submitted tumor samples prior to treatment for genomic/proteomic analysis (Paradigm, Phoenix, AZ.) Tumor response and associated molecular profiles were analyzed. The test evaluated over 137 genomic alterations with known actionable variations including mutations, gene-fusions, copy number variations, MRNA expression and protein expression analysis by IHC. Results: 76 patients were enrolled and 42 have completed treatment including definitive surgery and have reported data as of this date. The vast majority of patients had invasive ductal carcinoma with 16% having triple negative biology and 20% having Her2 biology. Of the triple negative patients with reported surgical results, 42% had a complete response or minimal residual disease, and the remaining 58% had a partial response. Of the patients with HER2 biology, 85% had a complete response and the remaining a partial response. 17% of patients with luminal biology had a complete response; the remaining had only a partial response or progression. Overall, 15 patients had a complete response, 4 had minimal residual disease and the remaining (over 50%) had a partial response, stable or progressive disease. Patients who did not achieve a complete response had multiple molecular aberrations with unique markers not present in patients with PCR. These included markers of known or possible drug resistance (IGFR1, CAIX), poor prognostic markers (TP53, MET, PTEN), biomarkers of response to approved treatment that were not utilized and other markers of potential response and research. Conclusions: Comprehensive genomic testing may predict resistant biology and provide additional targets for treatment or clinical study. Genomic analysis earlier in the patient’s care path may improve response rates by suggesting modifications in standard protocols or identifying clinical trials as potential first line options. Repeat genomic analysis may also suggest options for targeted adjuvant therapy for residual cancer after neoadjuvant therapy. Citation Format: Peter Beitsch, Pat Whitworth, Laura Lee, Antonio Ruiz, Rick Brown, Linsey Gold, Paul Baron, Rakesh Patel. Novel use of a precision medicine tool in the neoadjuvant therapy setting [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-16-21.