Thousands of women with early-stage breast cancer may be able to skip chemotherapy, according to a new study.

The study, published June 3 in the New England Journal of Medicine, finds that most patients with an intermediate risk of cancer recurrence can skip chemotherapy treatment without affecting their chances of surviving the disease.

Funded by the National Cancer Institute, various foundations and proceeds from the breast cancer research stamp, the study is the largest ever done on breast cancer treatment. Results could affect up to 70,000 patients annually in the United States and many more around the world.

"The impact is tremendous," study leader, Dr. Joseph Sparano of Montefiore Medical Center in New York, told the Associated Press. Most women who fit this criteria need only surgery and hormone therapy, he said.

Treatment decisions

For many patients, it's a difficult choice to decide whether to go through chemotherapy. The side effects are often harsh and debilitating.

But as the AP points out, in recent years, cancer treatment has been evolving and moving away from chemotherapy. Newer care includes gene-targeting therapies, hormone blockers and immune system treatments. If chemotherapy is used now, it's often used in lower doses and for shorter periods.

Jennifer Litton, an associate professor and oncologist at MD Anderson Cancer Center in Houston, told USA Today that the results will help patients and their doctors make more informed decisions.

"Moving forward, when women are making this decision, this study will help us put it into perspective and give them better advice next week than we were able to give them last week," said Litton, who attended the American Society of Clinical Oncology conference in Chicago where the results were discussed.

The study results

For the study, more than 10,000 women were given a genomic test for breast cancer called called Oncotype DX, which measures the activity of 21 genes involved in cell growth and predicts the risk that cancer will recur.

About 17 percent of the women tested had high-risk scores and were advised to have chemotherapy. About 16 percent with low-risk scores knew they could skip chemo. The 67 percent of women who were at intermediate risk all had surgery and hormone therapy. Half of that group also got chemotherapy.

After nine years, 94 percent of the women in both groups were still alive. About 84 percent also had no signs of cancer, so chemo treatment had no impact. Some women 50 or younger, however, did see benefits from chemo.

Gene testing can help make informed decisions about care and treatment, Dr. Harold Burstein of the Dana-Farber Cancer Institute in Boston, tells the AP. Many women think "if I don’t get chemotherapy I’m going to die, and if I get chemo I’m going to be cured," but the study shows there’s a sliding scale of benefits and sometimes none at all, he said.

Mary Jo DiLonardo covers a wide range of topics focused on nature, health, science and anything that helps make the world a better place.

Chemo may not be necessary for thousands of women with breast cancer, study finds
Landmark study finds that women with early-stage breast cancer can skip chemo without affecting their chances of beating the disease.