Breakthrough in Treatment of Most Common Type Breast Cancer: Helps Eliminate Chemo

A new study shows that more women can skip chemotherapy than previously believed.

For the study, the researchers focused their efforts on early stage breast cancer with no spread to lymph nodes and hormone-positive, meaning that the growth of their tumors was fueled by either progesterone or estrogen.

“Results from our registry suggest that adding molecular information provided by the Oncotype DX test is essential in order to spare low-risk patients the toxicity and side effects of chemotherapy”, said Prof.

Study leader Dr. Joseph Sparano, of Montefiore Medical Center in New York, NY, and colleagues recently presented their findings at the European Cancer Congress 2015 in Vienna, Austria.

Recent studies, however, have shown that a test called Oncotype DX is proving remarkably effective.

The study was sponsored by the National Cancer Institute. Not only were the trial subjects who skipped the chemo based on test results able to avoid other health risks often caused by the chemical cocktails, they also had less than 1% chance of their cancer popping up in other organs such as their liver and/or lungs 5-years after treatment. Over 100,000 women in the United States along are diagnosed with breast cancer every year.

“These studies from Israel and Germany provide additional strong evidence of the value of the test in guiding decision to treat with chemotherapy in mid-range and high-risk patients, complementing the findings of the TAILORx trial, which demonstrated that more than 99 percent of patients with low Oncotype DX Recurrence Score results of 10 or less had no distant recurrence at five years after treatment with hormonal therapy alone”, said Steven Shak, M.D., chief scientific officer, Genomic Health. The test measures the activity of genes that control cell growth, and others that indicate a likely response to hormone therapy treatment. The data safety monitoring board of the trial, as mandated by the study protocol, continues to monitor outcomes in patients with a Recurrence Score of 11 to 25 randomized to chemo-endocrine therapy or endocrine therapy alone. Continued follow-up still will be needed to determine whether any women in this larger group, with tumors in the intermediate-score range, can safely forgo chemotherapy. It should be noted, however, that the results for these groups are still pending, and that the research is still ongoing.

After five years, about 99 percent had not relapsed, and 98 percent were alive. What is more, the rate of invasive disease-free survival at 5 years was nearly 94%, while the risk of cancer returning at a distant site was less than 1%.

“These patients who had low risk scores by Oncotype did extraordinarily well at five years”, said Dr. Hope Rugo, a breast cancer specialist at the University of California, San Francisco, with no role in the study. These women were randomly assigned to receive either hormone therapy plus chemotherapy or hormone therapy alone.

This is good news for cancer patients, as many would prefer to avoid chemo.

Mary Lou Smith, a breast cancer survivor and advocate who helped design the trial for ECOG, the Eastern Cooperative Oncology Group, which ran it, said she thought women “would be thrilled” to skip chemo. “I’ve had chemotherapy. It’s not pretty”.