Published in the Journal of Clinical Oncology, SET2,3, and Recurrence Score were independent of each other and provided additive prognostic information when combined in post-menopausal patients with node-positive breast cancer.
Houston, TX, March 09, 2023 – Delphi Diagnostics, Inc announces the publication entitled, “Evaluation of the Sensitivity to Endocrine Therapy Index and 21-Gene Breast Recurrence Score in the SWOG S8814 Trial,” as a new online release in the Journal of Clinical Oncology, on January 17, 2023 1. This publication of an independent analysis by the National Cancer Institute’s Southwest Oncology (SWOG) clinical trials network further establishes the SET2,3 Index as providing additional and significant prognostic information to the currently available prognostic and predictive tests to inform treatment planning for patients with hormone receptor-positive (HR+), stage II/III breast cancer. This was also independent of whether these patients in the S8814 trial were randomized to receive anthracycline-based chemotherapy.
In this analysis of 283 patients, a blinded retrospective clinical validation analysis of SET2,3 in two randomized treatment arms from the SWOG S8814 trial comparing adjuvant anthracycline-based chemotherapy followed by tamoxifen endocrine therapy for 5 years versus tamoxifen alone. SET2,3 assay was calibrated and measured using whole-transcriptome RNA sequence of tumor samples already tested for Recurrence Score (RS). The primary endpoint was disease-free survival (DFS).
SET2,3 index and RS were not correlated (correlation coefficient was –0.04) and were independently prognostic. SET2,3 index did not predict benefit from anthracycline-based chemotherapy. SET2,3 was high in 93/175 (53%) patients with RS ≤ 25 (concordant low-risk), with 5-year DFS 97%. SET2,3 was low in 55/108 (51%) patients with RS > 25 (concordant high-risk), with 5-year DFS 53%. When the two tests were discordant, there was an identical prognosis, with a 5-year DFS of 79%-81%. Each component of the SET2,3 index (SETER/PR and BPI) was prognostic independently from RS.
“This publication further establishes the clinical need to evaluate endocrine sensitivity when making treatment decisions for breast cancer patients,” stated Winz Casagrande, Chief Executive Officer of Delphi Diagnostics.
The study’s authors concluded that SET2,3 and RS were independent of each other and provided added prognostic information when combined. The relevance highlighted by the journal editor was that combining these two genomic assays can add meaningfully to the prognostic assessment, and hence a need to determine when combined test results is appropriate. Discussion in the original manuscript 1 and an accompanying editorial 2 focused on the additive prediction of endocrine sensitivity and the opportunity for SET2,3 to inform adjuvant therapy recommendations, particularly novel therapeutic approaches using endocrine therapy.
1. PMID: 36649570,DOI: 10.1200/jco.22.01499, http://ascopubs.org/doi/full/10.1200/JCO.22.01499
2. PMID: 36701650,DOI: 10.1200/jco.22.02863, https://ascopubs.org/doi/abs/10.1200/JCO.22.02863
About SET2,3 Index
The SET2,3 Index is a measure of the level of transcriptional activity of genes that are related to receptors for the hormones estrogen and progesterone. It combines the SET index of transcription related to estrogen and progesterone receptors (SETER/PR) with a baseline prognostic index (BPI) derived from pathologic tumor size, nodal involvement, and molecular subtype by RNA4. A “high” SET2,3index has been shown to be associated with a good prognosis on endocrine therapies. In previous publications, SET2,3 index has been shown to provide prognostic information that is independent of response to prior chemotherapy and the 70-gene MammaPrint score in HR+ breast cancer.
About Delphi Diagnostics
Delphi Diagnostics Inc. is a Texas-based company focused on advancing clinically valid tests for the prognosis and prediction of breast cancer treatment. Delphi Diagnostics, Inc. holds an exclusive license from The University of Texas MD Anderson Cancer Center in Houston, TX to commercialize the SET technology that was developed by the laboratory of Dr. W. Fraser Symmans*. The Sensitivity to Endocrine Therapy test measures Sensitivity to Endocrine Therapy in all stages of HR+HER- breast cancer. The SET test is currently being used in prospective clinical trials. Delphi’s mission is to make the SET test available to breast cancer patients, maximize disease-free survival while minimizing toxicity, and avoid non-beneficial treatments.
To learn more, visit www.delphi-diagnostics.com.
*Dr. Symmans has a personal financial relationship with Delphi that has been identified as a conflict of interest with this research and is managed by MD Anderson’s Conflict of Interest Committee.
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