The OncoMasTR Test Predicts Distant Recurrence in Estrogen Receptor-Positive, HER2-Negative Early-Stage Breast Cancer: A Validation Study in ABCSG Trial 8

Clin Cancer Res. 2021 Nov 1;27(21):5931-5938. doi: 10.1158/1078-0432.CCR-21-1023. Epub 2021 Aug 11.

Abstract

Purpose: To validate the clinical performance of the OncoMasTR Risk Score in the biomarker cohort of Austrian Breast and Colorectal Cancer Study Group (ABCSG) Trial 8.

Experimental design: We evaluated the OncoMasTR test in 1,200 formalin-fixed, paraffin-embedded (FFPE) surgical specimens from postmenopausal women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative primary breast cancer with 0 to 3 involved lymph nodes in the prospective, randomized ABCSG Trial 8. Time to distant recurrence (DR) was analyzed by Cox models.

Results: The OncoMasTR Risk Score categorized 850 of 1,087 (78.2%) evaluable patients as "low risk". At 10 years, the DR rate for patients in the low-risk group was 5.8% versus 21.1% for patients in the high-risk group (P < 0.0001, absolute risk reduction 15.3%). The OncoMasTR Risk Score was highly prognostic for prediction of DR in years 0 to 10 in all patients [HR 1.91, 95% confidence interval (CI) 1.62-2.26, P < 0.0001; C-index 0.73], in patients that were node negative (HR 1.79, 95% CI, 1.43-2.24, P < 0.0001; C-index 0.72), and in patients with 1 to 3 involved lymph nodes (HR 1.93, 95% CI, 1.44-2.58, P < 0.0001; C-index 0.71). The OncoMasTR Risk Score provided significant additional prognostic information beyond clinical parameters, Ki67, Nottingham Prognostic Index, and Clinical Treatment Score.

Conclusions: OncoMasTR Risk Score is highly prognostic for DR in postmenopausal women with ER-positive, HER2-negative primary breast cancer with 0 to 3 involved lymph nodes. In combination with prior validation studies, this fully independent validation in ABCSG Trial 8 provides level 1B evidence for the prognostic capability of the OncoMasTR Risk Score.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Anastrozole / therapeutic use
  • Antineoplastic Agents, Hormonal / therapeutic use
  • Breast Neoplasms / chemistry
  • Breast Neoplasms / diagnosis*
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / genetics
  • Female
  • Genetic Testing*
  • Humans
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnosis*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Staging
  • Prospective Studies
  • Randomized Controlled Trials as Topic
  • Receptor, ErbB-2 / analysis
  • Receptors, Estrogen / analysis
  • Retrospective Studies
  • Tamoxifen / therapeutic use

Substances

  • Antineoplastic Agents, Hormonal
  • Receptors, Estrogen
  • Tamoxifen
  • Anastrozole
  • Receptor, ErbB-2