By Nancy Gay
Thousands of women with the most common form of breast cancer may not have to undergo chemotherapy treatment. That’s according to a new study published in the New England Journal of Medicine.
The study called TAILORx looked at women with early hormone-receptor-positive, HER2-negative, axillary-node-negative breast cancer, which accounts for about half of all breast cancer cases.
By performing genetic tests on tumor samples, researchers were able to identify women who could swap chemotherapy for a drug that either blocks the hormone estrogen or prevents the body from making it. Known as endocrine therapy, these hormone-blocking medicines like tamoxifen are an essential part of treatment for many breast cancer patients because they lower the risk of recurrence, new breast tumors and death.
Patients affected by the study are those who test negative for a protein called HER2 and have:
- Early-stage breast tumors measuring one to five centimeters that have not spread to lymph nodes;
- A sensitivity to estrogen
- A score of 11 to 25 on a widely used test that gauges the activity of a panel of genes involved in cancer recurrence.
Dr. Hatem Soliman, a medical oncologist in Moffitt Cancer Center’s Breast Oncology Program, says, "The TAILORX trial provides us additional evidence that genomic assays can identify women who will do well with endocrine therapy alone for their breast cancer. However, the data also shows that additional clinical factors such as age or stage should be considered in combination with the genomic test when evaluating the need for chemotherapy."
Approximately 123,000 women in the United States and 23,000 women in the United Kingdom are diagnosed with the particular form breast cancer each year. The standard care for most patients currently involves chemotherapy and endocrine therapy.
The gene test, called Oncotype DX Breast Cancer Assay, has been available since 2004 and scores patients from 0 to 100. It costs about $3,000 and is usually covered by insurance.