# CTRIAL-IE (ICORG) 15–34: The impact of the 21 gene breast recurrence score® assay on chemotherapy prescribing in oestrogen receptor positive, lymph node positive early stage breast cancer in Ireland

## TL;DR

This study shows that using a 21-gene test in Ireland reduced chemotherapy recommendations for certain breast cancer patients.

## Contribution

The study demonstrates the real-world impact of the 21-gene Recurrence Score® assay on chemotherapy use in Ireland.

## Key findings

- Access to the test reduced chemotherapy recommendations from 92% to 65%.
- The reduction was most significant in patients with one or two lymph nodes involved.
- The test became standard of care following the study.

## Abstract

The 21-gene Breast Recurrence Score® (Oncotype DX®) assay has improved the selection of patients for chemotherapy in early breast cancer. Internationally, this test is used in lymph node positive disease, but at the time this study was conducted, it was not reimbursed for this indication in Ireland.

Determine how access to the Recurrence Score® testing reduces chemotherapy use and quantifies the impact on oncologists’ treatment recommendations.

Between March and September 2017, 75 patients were enrolled in a prospective study across ten hospitals. Eligible patients had oestrogen/progesterone receptor positive and HER2 negative breast cancer with 1–3 involved lymph nodes. Following informed consent, demographics were collected and questionnaires completed by a consultant medical oncologist before and after the recurrence score testing, which examined expectations of tumour chemosensitivity, strength of chemotherapy recommendation, and planned treatment.

Recurrence Scores® were available on 74/75 patients. Overall, access to this test led to a 27% reduction in the recommendation for chemotherapy from 68 (92%) to 48 (65%) patients. This was most notable in patients with one (46 versus 34 patients) and two (13 versus seven patients) involved lymph nodes representing a 26% and 46% reduction, respectively. The reduction in chemotherapy use was marked in women aged 50–70 years with one lymph node involved (28 versus 18 patients)—a 36% reduction.

Consistent with our hypothesis, broader access to the Recurrence Score® led to a reduction in the use of chemotherapy in Ireland and has subsequently become standard of care.