Patients with hormone receptor (HR)-positive, HER2-negative, axillary lymph node (LN)-negative breast cancer who have a recurrence score of 11 to 25 may not benefit from chemotherapy, according to a study published in Cancer.1
Patients with HR-positive, HER2-negative, LN-negative tumors who have a 21-gene expression assay recurrence score of 0 to 10 have excellent invasive disease-free survival rates; however, the outcomes of patients with a recurrence score of 11 to 25 treated with endocrine therapy alone remain unclear.
For the study, investigators retrospectively analyzed data from 1424 patients diagnosed between 2005 and 2011 who received care at a single institution and underwent a 21-gene expression assay.
Of those, 21% had a recurrence score of 0 to 10, 63% had a score of 11 to 25, and 16% had a score higher than 25. Nearly 2%, 15%, and 73% of patients with recurrence scores of 0 to 10, 11 to 25, and higher than 25 received chemotherapy, respectively.
At a median follow-up of 58 months, results showed that patients with a recurrence score of 11 to 25 had an invasive disease-free survival rate of 92.6% (95% CI, 89.6-94.7) at 5 years.
Investigators found that receipt of chemotherapy had no significant effect on invasive disease-free survival (hazard ratio [HR], 1.64; 95% CI, 0.73-3.71) among patients with a recurrence score of 11 to 25.
The study further demonstrated no significant association between chemotherapy and recurrence-free survival (HR, 1.46; 95% CI, 0.41-5.23), distant recurrence-free survival (HR, 1.46; 95% CI, 0.32-4.92), or overall survival (HR, 2.19; 95% CI, 0.44-11.0) benefit in this subgroup.
Although the findings suggest that patients with HR-positive, HER2-negative, LN-negative breast cancer and a recurrence score of 11 to 25 have similar outcomes regardless of whether they received chemotherapy or not, the authors conclude that a benefit from chemotherapy cannot be ruled out.
1. Barcenas CH, Raghavendra A, Sinha AK, et al. Outcomes in patients with early-stage breast cancer who underwent a 21-gene expression assay. Cancer. 2017 Feb 15. doi: 10.1002/cncr.30618. doi: 10.1002/cncr.30618 [Epub ahead of print]