Additional Support for Benefit of 21-Gene Assay in Early-Stage Breast Cancer: A Subgroup Analysis of TAILORx

The following article features coverage from the European Society for Medical Oncology (ESMO) 2019 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

According to results of a secondary analysis of data from the prospective TAILORx trial (ClinicalTrials.gov Identifier: NCT00310180) presented at the European Society for Medical Oncology (ESMO) Congress 2019 held in Barcelona, Spain, the rate of 5-year distant-free recurrence was more than 90% for women with node-negative, hormone receptor-positive, ERBB2 (HER2)-negative early-stage breast cancer who had a 21-gene assay recurrence score (RS) of 26 to 100 and were mostly treated with adjuvant taxane and/or anthracycline-based combination chemotherapy in addition to adjuvant endocrine therapy ^1,2

Results of previous studies of the Oncotype DX, 21-gene assay have shown that it provides both prognostic and predictive information for women with early-stage, axillary node-negative, hormone receptor-positive, HER2-negative early-stage breast cancer,² thereby facilitating patient selection for adjuvant chemotherapy.

Specifically, based on results of the 21-gene assay, patients are assigned a recurrence score (RS) — with a RS of 26 to 100 considered to be “high” and associated with an increased risk of disease recurrence, as well as an increased likelihood of benefit from adjuvant chemotherapy.^2,3

In this subgroup analysis from the TAILORx trial, these end points were reassessed in a larger population of patients with a high RS who were more likely to receive more modern, standard-of-care adjuvant chemotherapy regimens.

Of the 1389 women with a RS of 26 to 100 enrolled in the TAILORx trial, 84% of patients received adjuvant chemotherapy including a taxane and/or an anthracycline, with 9% and 6% receiving other types of chemotherapy and no chemotherapy, respectively.^1,2

At a median follow-up of 61 months, the estimated 5-year rates of distant disease-free recurrence, distant and/or local/regional disease-free recurrence, and overall survival were 93.0%, 91.0%, and 95.9%, respectively, for this subgroup of patients.1^,2

In comparison, a 5-year distant disease-free recurrence rate of 78.8% was estimated for patients with a high RS who were treated with endocrine therapy alone, based on analyses including data from the National Surgical Adjuvant Breast and Bowel (NSABP) B-20 study.^2,3

“The findings from this analysis add to the evidence base supporting the use of the 21-gene RS assay to guide the use of adjuvant chemotherapy in patients with hormone receptor–positive, ERBB2-negative, axillary node-negative breast cancer,” the study authors noted in conclusion.²

Read more of Cancer Therapy Advisor‘s coverage of the ESMO annual meeting by visiting the conference page.

References

1. Sparano J, Gray RJ, Makower D, et al. Clinical outcomes by chemotherapy regimen in patients with RS 26-100 in TAILORx. Presented at: European Society for Medical Oncology (ESMO) Congress 2019; September 27-October 1, 2019: Barcelona, Spain. Abstract LBA18.
2. Sparano J, Gray RJ, Makower DF, et al. Clinical outcomes in early breast cancer with a high 21-gene recurrence score of 26 to 100 assigned to adjuvant chemotherapy plus endocrine therapy: A secondary analysis of the TAILORx randomized clinical trial. JAMA Oncol. doi: 10.1001/jamaoncol.2019.4794
3. Paik S, Tang G, Shak S, et al. Gene expression and benefit of chemotherapy in women with node-negative, estrogen receptor-positive breast cancer. J Clin Oncol. 2006;24:3726-3734.