Pharmaceuticals (Mar 2015)

A Retrospective Study of the Impact of 21-Gene Recurrence Score Assay on Treatment Choice in Node Positive Micrometastatic Breast Cancer

  • Thomas G. Frazier,
  • Kevin R. Fox,
  • J. Stanley Smith,
  • Christine Laronga,
  • Anita McSwain,
  • Devchand Paul,
  • Michael Schultz,
  • Joseph Stilwill,
  • Christine Teal,
  • Tracey Weisberg,
  • Judith F. Vacchino,
  • Amy P. Sing,
  • Dasha Cherepanov,
  • Wendy Hsiao,
  • Eunice Chang,
  • Michael S. Broder

DOI
https://doi.org/10.3390/ph8010107
Journal volume & issue
Vol. 8, no. 1
pp. 107 – 122

Abstract

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To assess clinical utility of the 21-gene assay (Oncotype DX® Recurrence Score®), we determined whether women with HER2(−)/ER+ pN1mi breast cancer with low (<18) Recurrence Scores results are given adjuvant chemotherapy in a lower proportion than those with high scores (≥31). This was a multicenter chart review of ≥18 year old women with pN1mi breast cancer, HER2(−)/ER+ tumors, ductal/lobular/mixed histology, with the assay ordered on or after 1 January 2007. One hundred and eighty one patients had a mean age of 60.7 years; 82.9% had ECOG performance status 0; 33.7% had hypertension, 22.7% had osteoporosis, 18.8% had osteoarthritis, and 8.8% had type-2 diabetes. Mean Recurrence Score was 17.8 (range: 0–50). 48.6% had a mastectomy; 55.8% had a lumpectomy. 19.8% of low-risk group patients were recommended chemotherapy vs. 57.9% in the intermediate-risk group and 100% in the high-risk group (p < 0.001). A total of 80.2% of the low-risk group were recommended endocrine therapy alone, while 77.8% of the high-risk group were recommended both endocrine and chemotherapy (p < 0.001). The Oncotype DX Recurrence Score result provides actionable information that can be incorporated into treatment planning for women with HER2(−)/ER+ pN1mi breast cancer. The Recurrence Score result has clinical utility in treatment planning for HER2(−)/ER+ pN1mi breast cancer patients.

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