Newly published results of a nine-year clinical trial are changing treatment plans for tens of thousands of people with early-stage breast cancer. The study showed that many patients who are diagnosed with a common type of early-stage breast cancer may not need chemotherapy.
Until now, the proven treatment for early-stage breast cancer typically involved a combination of surgery (and sometimes radiation therapy), hormone therapy and chemotherapy to kill any potentially remaining cancer cells. However, the results of the clinical trial, recently published in the New England Journal of Medicine, found chemotherapy did not benefit the majority of the women who participated in the trial. Hormone therapy without chemotherapy kept the women disease-free for years.
Called TAILORx, the clinical trial studied women with early-stage hormone-receptor positive, HER2 negative, axillary lymph node-negative breast cancer. In layman’s terms, a hormone-positive tumor means the breast cancer cells need hormones like estrogen and progesterone to grow. HER2 is a cancer protein, and axillary lymph node-negative means the cancer has not spread to the lymph nodes in the underarm. More than 10,000 patients with this type of cancer enrolled in the TAILORx trial, and researchers kept track of their health over the course of nine years.
The trial’s results are based on testing the genetics of the tumor. Patients who enrolled in the trial were given the Oncotype DX test, a 21-gene expression test that assigns a score to determine the risk of the cancer reoccurring. Per the traditional standard of care, women in the low-risk category received hormone therapy only, women in the high-risk category received hormone therapy and chemotherapy. Women in the intermediate category were randomly assigned to one of two groups: only hormone therapy or hormone therapy and chemotherapy. After nine years, 94 percent of the women in both of the intermediate-risk groups were still alive, and 84 percent of all the women showed no signs of cancer. These results show hormone therapy – which is a hormone-blocking pill – provided the intermediate-risk patients with the biggest benefit. Chemotherapy provided additional benefit high-risk patients only.
This is a huge discovery, and cancer specialists are now taking this new information into account when designing treatment plans for their patients. Today, we have more information about tumor biology and how certain tumors respond to hormone therapy, though not all women with early-stage breast cancer need to get their tumor’s genes tested. Part of a chemotherapy doctor’s expertise is to become familiar with a patient’s tumor size and grade and determine whether additional information, like genetic testing, is needed. For patients wondering if they can forgo chemotherapy, it is important to have this conversation with a chemotherapy doctor (also called a medical oncologist).
In light of the TAILORx trial results, I and cancer doctors around the world have received questions from patients, asking if they can skip chemotherapy or why chemotherapy was part of their treatment plan in the past. One of the great benefits of medical research is the treatment advances it generates. We base our care plans for patients on the most current evidence-based treatment. People with early-stage breast cancer five or ten years ago received the proven standard of care as it was known at the time for their particular cancer.
The TAILORx trial demonstrates why doing clinical research and having clinical trials available is so valuable. As cancer care becomes more personalized, I expect more important discoveries down the road that will lead to new treatments and changes in the standards of care for the better.