When a woman is diagnosed with breast cancer, her doctors are not just looking at how to treat it but also the chance it might come back.

For years it was determined by lab results.

"Those include the size of the tumor and whether the lymph nodes are involved whether it looks aggressive under the microscope. But it's an imperfect tool," said Dr. Gribbin, a medical oncologist for Mercy Health. He says because of that imperfection, many women were being treated with chemotherapy who didn't need it. “We want to spare woman who don't need this treatment being at risk for those long-term side effects."

That's where genetic testing is making a difference.

For the past 10 years, Mercy Health has been using a test called Oncotype DX to look at the genetic makeup of cancer cells.

"It's not a perfect test, and it substantially reduces the odds of making a mistake and probably spares 30-40% of women chemotherapy. But it's still a little bit of an unknown," says Gribbin.

That's where a recently-completed clinical trial comes in. It involved 6,700 women at over 100 medical centers in nine countries.

The clinical trial involved MammaPrint, a similar genetic testing tool like the one used at Mercy Health. It found that when the test recommended a low possibility of cancer returning and no chemotherapy was used patients had a 95% survival rate.

Dr. Gribbin says the study shows the importance of the evolving field of genetic testing, "This is a tool and a very interactive discussion about what is the risk and how would this patient like to manage it. Sometimes I say to a woman, 'All our tests say you have a 10% chance of this coming back. And I can say we can reduce that to 4 or 5% with chemotherapy,' and some women will say, 'I will do everything I can to make that number smaller.' Other women might say unless my risk is 50-50, I'm going to take my chances because I'm concerned about chemotherapy and its side effects."

Dr. Gribbin agrees that both types of tests do one important thing: give patients the information they need to make the right choice for their treatment. "Over time, we'll get closer and closer to treating the right people."
And in the end, we'll all have more Friends For Life.