Individualized Treatment Decisions for Breast Cancer

Posted on: June 15, 2018

The long-awaited results from the TailoRx (Trial Assigning Individualized Options for Treatment) trial were released in June at the American Society of Clinical Oncology in Chicago. The results confirm that using the gene expression test (OncotypeDX) to assess the risk of breast cancer recurrence can spare many women unnecessary treatment with chemotherapy that will not benefit them.

The most common type of cancer in women is breast cancer with over 266,000 new cases expected in the United States this year. The majority of these cases will be estrogen receptor (ER) positive, HER2-negative, axillary lymph node negative breast cancer. While many of these patients require chemotherapy to achieve the best outcome, there are many patients who will do just as well with endocrine (hormonal) treatment alone, without the added toxicities of chemotherapy.

For several years, medical oncologists have utilized the prognostic information of gene expression assays like OncotypeDX for patients with ER-positive breast cancer to help them better predict which patients would benefit from chemotherapy. OncotypeDX’s gene-expression assay provides a recurrence score range from 0 to 100. Previous studies have shown that a patient with a high risk recurrence score would benefit from receiving adjuvant chemotherapy and a patient with a low risk recurrence score would not likely benefit from adjuvant chemotherapy. For the patient with an intermediate recurrence score, we were uncertain of the benefit of adjuvant chemotherapy.

The goal of this trial, which was supported in part by the National Cancer Institute (NCI), was to address this gap of knowledge by determining whether chemotherapy is beneficial for women with an intermediate risk recurrence score of 11-25. It was a prospective clinical trial that enrolled over 10,000 women with this subset of breast cancer at 1,182 sites in the United States, Australia, Canada, Ireland, New Zealand, and Peru. In fact, several of our patients from Diablo Valley Oncology participated in the trial. According to the authors, the findings suggest that chemotherapy may be avoided in about 70 percent of women with ER-positive, HER2-negative, node-negative breast cancer. The findings also suggest that chemotherapy should be considered for the remaining 30 percent of women with ER-positive, HER2-negative, node-negative breast cancer:

The results of this ground breaking trial confirm that the majority of the ER-positive patients can avoid chemotherapy and just receive hormonal therapy. The findings are very helpful in supporting oncologists and patients when they are making decisions about the best course of treatment.

Dr. Svahn is a Medical Oncologist and Breast Cancer Specialist with Diablo Valley Oncology and Hematology Medical Group in Pleasant Hill and San Ramon.   She developed the Women’s Cancer Center of the East Bay where breast cancer patients are seen by three breast cancer specialists in one visit. Dr. Svahn can be reached at 925-677-5041