DALLAS (CBS 11 NEWS) –  Deborah Kirby will never forget her 61st birthday last year. That was the day she learned she had breast cancer.

“At first, I just said, ‘don’t do the chemo—just remove ‘em! I don’t need ‘em anyway.’” It is, doctors say, a fairly common reaction.  But, groundbreaking research underway right now in North Texas is helping breast cancer patients avoid mastectomies and make treatment decisions based on fact, not fear.

“It’s incredible,” said Peter Beitsch, MD, a surgical oncologist at Medical City Hospital in Dallas.  “We’re right on the cusp of a revolution in breast cancer and lots of different kinds of cancers.”

For the past two years, Dr. Beitsch has been leading a major clinical study conducting genetic analysis of breast cancer tumors.  The information is then used to design a patient specific treatment plan.

“In this study, we were trying to take big tumors and shrink them so that fewer women would have to get a mastectomy,” explained Dr. Beitsch.  “It also gives us info on their specific chemo effect, whether the chemo they’re getting is working for them.”

Beitsch says the ability to assess the effectiveness of the chemo prior to surgery is groundbreaking because treatment protocols are typically ‘one size fits most’, and there are many different kinds of breast cancer. “And what we found was in the study that about 25-percent of the time, we think it’s one kind and when you do the genetic analysis, it’s a different kind and that can have a profound impact on how you treat them.”

For Kirby, a registered nurse, the genetic analysis meant she was able to avoid a mastectomy, while getting almost immediate reassurance that the chemotherapy was working. “By the time they finished with the chemo and everything there was no tumor,” she said.  “There was nothing.  You couldn’t feel anything, so I thought, ‘well, cancel that surgery!’”

About 1,000 patients are involved in the clinical study, which is expected to conclude in the fall of 2014.

According to Dr. Beitsch, advances in technology have made the testing and more refined treatment possible. “It’s very exciting.  Therapies are getting more targeted.  They are really tailored to the patient, now, instead of populations of patients.”

And while the doctors stresses that patients who opt for mastectomies can still pursue that treatment, Beitsch says more options are always better. “They were going to get chemo anyway, and so we gave it to them up front and they could see the tumor melting.  It’s amazing.”