Some doctors now examine the 'genomic profile' of breast cancer to help tailor their treatment recommendations.

Once a breast cancer patient is treated locally with surgery--or targeted radiation--to clear a tumor from the body, the next step is sometimes to order genomic testing to scan the DNA-level programming of the cancer.

Several companies offer the tests, including the brand names Oncotype DX and Mammaprint.

"We answer the question: is there a high risk for the cancer coming back?" said Neil Barth, chief medical officer of Agendia. His company makes Mammaprint.

In standard care, tumor cells are examined under a microscope. Barth said the resulting pathology report describes how bizarre the cancer cells look, compared to healthy cells, and is one way that doctors categorize a cancer and make guesses about whether it is aggressive and likely to spread outside the breast to other parts of the body such as brain and bone.

A key to knowing the 'performance' of a cancer 

Genomic testing is an add-on tool to understand the biology of a cancer and make informed guesses about how a cancer will behave in the future.

"Tumors can look very quiet and calm under the microscope, and then have bad biologic behavior," said breast surgeon Beth DuPree, medical director of the breast health program at Holy Redeemer Health System.

Barth uses the analogy of buying a used car to help explain the technology.

When you check-out a car sitting in someone's driveway, you can tell that it's white, has four doors and maybe a few rust spots. It's harder to know exactly what's under the hood and how the car will perform on the highway.

"Genomic testing provides information on the performance of cancer," Barth said.

Not every tumor needs to be treated with chemotherapy. DuPree says genomic testing helps her decide which cancers do and which don't.

Aggressive tumors know how to get out of the breast and find another place to live, and in that case patients are candidates for chemotherapy. Instead of targeting cancer located only in the breast, chemotherapy is a systemic treatment that tries to wipe out cancer throughout the body.

Other tumors are "lazy," DuPree said. "So in those tumors, chemotherapy is not as effective, because cells need to be dividing at a rapid rate for chemotherapy to be most effective," she said.

DuPree has participated in speaker training for the makers of both Mammaprint and Oncotype and was compensated for education sessions conducted at Holy Redeemer.

Genomic testing is often one more test result to wait for during time of lots of tough decisions.

"You have so many facts and figures kind of being thrown at you, and you are kind of off balance when you find out that you have cancer to begin with," said Cari Grundman, 51.

She learned about genomic testing while she was recovering from a mastectomy. She was hoping to hear that her treatment was complete when a medical assistant mentioned that the doctors were waiting for Grundman's genomic results.

"I said: What?! I don't remember anything about an Oncotype test," she said.

That first round of genomic testing put Grundman in a middle ground: it wasn't clear if she would benefit from chemotherapy. She sought out second opinions but the advice was mixed.

"One group said: "Yes absolutely you need to get the chemotherapy. Others were saying 'it's your decision'," Grundman said.

Then, doctors offered her Mammaprint, a second, newer genomic test.

Eventually Grundman learned that even though her tumor was small, the cancer was high risk. "Now you have an answer," she said.

Grundman says ultimately genomic testing offered her more certainty that chemotherapy was the right choice for her.

Precision medicine, personalized care 

Jefferson University Hospital Nurse Practitioner Liz Santarsiero says that's the idea behind genomic testing: to give women personalized—precision--medicine.

"It's about you, not about everybody else," Santarsiero said.

With genomic profiling, Santarsiero says she can talk with women about their particular kind of cancer beyond the second-hand experience of friends, family members or neighbors who've heard the diagnosis, too.

"For some patients it helps them understand why they don't need chemotherapy," Santarsiero said.

Montgomery County mom Chris Pierce was diagnosed with breast cancer in 2012.

Her surgeon, Beth DuPree told Pierce she had a large, 'lazy' tumor that had likely been 'smoldering' in her breast for years. A Mammaprint test suggested that Pierce could safely skip chemotherapy.

"At the time, all it meant to me, initially, was I didn't need chemotherapy," Pierce said.

Chemotherapy has tough side effects that patients want to avoid, but it's also protection—DuPree said--against a cancer that's likely to strike again.

"You can't buy hurricane insurance the day after the storm hits your beach house, so to me chemotherapy is often like buying an insurance policy," DuPree said.

Pierce was able to return to work quickly after surgery, and her only follow-up treatment was a once-a-day prevention pill. That was all good news, still she's a wife and mother--says she wanted to be absolutely sure she was doing everything she could to be around for her family.

"Do you need it, do you not need it? You think to yourself, if I could only know it [the cancer] wasn't going to come back, I wouldn't bother to get chemo," Pierce said. "I kind of think of this [genomic testing] as my little crystal ball. Obviously it isn't 100 percent, nothing is," Pierce said.

Pierce and Grundman are both part of a group of unpaid volunteers who get updates on the Mammaprint technology, and agree to speak about their experience.

Research efforts continue 

Many cancer specialists are still learning about genomic testing, and research is still underway to figure out which patients would benefit most. 

Breast surgeon Beth DuPree recommends the testing for her patients with early-stage disease. When a cancer has spread outside the breast into other parts of the body, she absolutely recommends chemotherapy.

"So in those cases there's no reason to get this test," DuPree said. "This goes back to the first year of surgical residency when your attendings say don't order a test if it's not going to potentially change the management of a patient. That should be the standard for holding doctors accountable."

The tests cost about $4,000 each and is accepted by some insurance companies.