SAN ANTONIO — Treatment plans for women with estrogen receptor–positive early-stage breast cancer were significantly altered in up to 40% of cases in response to the additional information provided by Oncotype DX 21-gene recurrence score assay results, according to two physician surveys presented at the San Antonio Breast Cancer Symposium.
The general trend was for the Oncotype DX results to revise planned adjuvant treatment downward toward a less aggressive approach.
One survey involved 160 medical oncologists faced with patients with ER-positive breast cancer with 1–3 positive axillary lymph nodes. In the 138 cases where the physician had a specific treatment recommendation before receiving the Oncotype DX results, the recommended regimen was changed from chemotherapy plus hormone therapy to hormone therapy alone in 46 patients (33%) based on the additional information provided by the recurrence score assay, reported Dr. Ruth Oratz of New York University's School of Medicine.
Dr. Oratz said that she is on the speakers bureau for Genomic Health, which markets the Oncotype DX assay.
In addition, 13 patients (9%) were switched from planned hormone therapy to chemotherapy plus hormone therapy in response to the Oncotype DX data.
Fifty-three percent of patients in this series had a low Oncotype DX recurrence score below 18, another 38% had an intermediate score, and 9% had a recurrence score of 31 or more.
A separate survey presented in San Antonio involved the medical oncologists, surgeons, and pathologists for 154 consecutive women with early-stage, ER-positive breast cancer that was node negative in 130 cases.
Based on the standard clinicopathologic features alone, the physicians overestimated the patients' recurrence risk in 32% of cases and underestimated it in 14%, according to Dr. Geza Acs of H. Lee Moffitt Cancer Center & Research Institute, Tampa.
Dr. Acs, like Dr. Oratz, is on the speakers bureau for Genomic Health, which markets Oncotype DX.