Study: Genetic Test May Allow Breast Cancer Patients To Avoid Chemotherapy

NEW YORK (CBSNewYork) -- Women diagnosed with early stage breast cancer are often recommended to have chemotherapy, but it is hard to tell whether the approach will actually improve a woman's survival.

But as CBS2's Dr. Max Gomez reported, a genetic test may now spare some women the misery.

Diane Heditsian is a two-time early stage breast cancer survivor. She had chemotherapy in 2002 after she was first diagnosed.

"You have exhaustion that isn't helped by sleep, and you get cognitive impairment – you're not thinking clearly," Heditsian said.

Ten years later, doctors found a different type of breast cancer.

"I really didn't want to go through chemotherapy again," she said.

So doctors recommended the MammaPrint test, which analyzes 70 genes. A new study looked at more than 3,000 breast cancer patients, and found that many early stage patients could safely avoid chemotherapy after surgery.

"Women with biologically low-risk tumors, even if they're clinically high-risk, don't benefit from chemotherapy," said Dr. Laura Esserman of the UCSF Carol Franc Buck Breast Care Center.

Until recently, a large tumor or cancer cells in the lymph nodes automatically meant chemotherapy.

"If you are low-risk, you have just as good an outcome at five years if you don't have chemotherapy, compared to those who get chemotherapy," Esserman said.

Heditsian's score on the test was ultra-low, so she had a lumpectomy and radiation but no chemo.

"I was just so relieved," she said. "I run my own business. I have a very active life."

Heditsian now works to educate other women about the disease, and she is currently cancer-free.

While some women and doctors look at chemo as an extra bit of insurance against cancer recurrence, those powerful drugs can have serious, sometimes long lasting side effects. So the possibility of safely avoiding them is a big plus for women.

A different gene test called Oncotype DX has also been shown to predict which women can safely skip chemo.

The study was presented at the annual meeting of the American Association for Cancer Research.