Inherited Risk

It was a call that Dawn, 35, a fourth-grade teacher in Wylie, Texas, had been anticipating for weeks, and the report was this: She had tested positive for an inherited mutation in the gene known as PALB2 – a mutation that made her high-risk for eventually developing breast cancer.

Dawn - a UT Southwestern Cancer Patient - Hereditary Breast Cancer
Dawn Davis, 35, tested positive for an inherited mutation in the gene known as PALB2 - a mutation that made her high-risk for eventually developing breast cancer.

Like the better-known BRCA1 and BRCA2 genes, which account for nearly 50 percent of the major inherited breast cancer predisposition syndromes, PALB2 makes a protein that works to keep DNA healthy.

While identifying a genetic mutation can be important for determining risk, so is knowing the history of the disease in an individual’s family. And in Dawn’s case, that was not good news at all.

Another Culprit

Remarkably, Dawn’s maternal grandmother and six of her grandmother’s seven sisters had developed breast cancer, and five of them had died from it. The disease was so prevalent, in fact, the family was chosen, in 2004, to be part of a landmark genetics study conducted by the University of Washington’s Mary-Claire King, Ph.D., who first identified the BRCA1 gene’s connection to inherited breast cancer. 

But none of Dawn’s relatives had tested positive for a BRCA gene mutation in the study, so clearly, researchers knew, there was another culprit causing the family’s cancer. The relatively recent advent of next-generation sequencing technology enabled testing for a whole panel of additional genes.

Once PALB2 was identified as the source, Dawn’s mother, Chris, tested positive for that mutation. When Chris received word in August 2012, Dawn and her younger sister did not hesitate to be tested themselves. They knew they each had a 50 percent chance of having the mutation, too.

‘Ticking Time Bombs’

Dawn and her sister were “99 percent certain,” even when they sent in their blood-work, that if their tests came back positive they would opt for having a prophylactic double mastectomy. By that freezing day in January, the results were in: Dawn had it;  her sister did not.

Although stunned by the news, Dawn remained positive about what she wanted to do.

“After getting the test results, I thought of my breasts as suddenly being these ticking time bombs that were attached to me that I had to do something about. I just did not want there to even be a chance of developing breast cancer, and with my family’s history, that chance was there. 

"Of course, it was a very, very emotional time, but once the reality started sinking in, I also felt very empowered with the knowledge that I now had and that I could be proactive and actually do something about it."

A Call to UTSW

Dawn’s genetic counselor put her in touch with UT Southwestern’s Mary L. Brown Breast Cancer Genetics and Risk Assessment Clinic.

After discussing Dawn’s options with her, breast cancer surgeon David Euhus, M.D., one of several genetic specialists on the UTSW team, performed her preventive double mastectomy on June 18. Plastic surgeon Sumeet Teotia, M.D., began Dawn’s reconstructive surgery the same day.

Dawn has no regrets about choosing a preventive mastectomy. “Aside from having to learn to sleep on my back in those first months and to just listen to my body and relax, the whole thing went better than I could have imagined, and I would make the same decision today,” she says.

Dawn and her mother, Chris
Dawn and her mother, Chris

Choosing an Alternate Path

Dawn’s mom, Chris, joined her daughter for her initial appointments at UT Southwestern. Although Chris was, at the time, a patient at MD Anderson Cancer Center in Houston, she decided to move her care to UTSW and, in fact, had her first appointment here the same week as Dawn’s surgery.

“The knowledge base surrounding the genetic testing available at UT Southwestern made the difference in that decision,” says Chris, 60. “The comfort level that knowledge brought about was just extremely important to me - both for my daughter’s sake and my own. I don’t even live in Dallas, but I felt that I would be getting the utmost of care by people who speciffcally knew about PALB2. It’s something relatively new, and clearly not everyone is really up on the science involved – or maybe it’s just that UT Southwestern doctors are way up on the science of it.”

Although initially Chris felt, like her daughter, “99 percent certain” that she would choose to have a mastectomy, she later felt, after talking to doctors at both MD Anderson and UT Southwestern, that choosing to undergo enhanced surveillance – with alternating mammograms and MRI exams conducted every six months – was the best option for her.

Laying Out the Options

According to Linda Robinson, M.S., UT Southwestern’s Assistant Director of Clinical Cancer Genetics, both Chris’ and Dawn’s treatment decisions, while very different, make sense for them as individuals.

“The decision to have a mastectomy is very personal, and we never tell somebody that it’s the only way,” she says. “We lay out the options, first encouraging a healthy lifestyle, then talking about enhanced surveillance, then talking about chemo prevention, and then coming to the final option, the mastectomy. We always say that a well-informed patient can’t make a bad decision.”

Ms. Robinson notes that, in general, with inherited genetic syndromes, once a patient reaches age 60, her risk is actually starting to decline because she has shown she has some other gene that is opposing the abnormal gene. Thus, because she has out-lived much of the risk, Chris’ decision  for enhanced surveillance is right for her.

As for Dawn, “Some patients just know, once they find out they’re facing such a  high risk, that they want to proactively manage the situation,” Ms. Robinson says. “They want to put it behind them and move on with life. And that’s exactly what Dawn is doing.”

Who's At Risk?

Inherited breast cancer accounts for only 5 to 7 percent of all breast cancer. The risk for the inherited form is higher when you or a family member have: 

  • Breast cancer diagnosed at an unusually young age
  • Multiple relatives on the same side of the family with breast cancer
  • Breast or ovarian cancer in a family with Ashkenazi Jewish ancestry (Eastern or Central European descent)
  • A combination of breast and ovarian cancers or rare cancers like sarcomas, pancreatic cancer, or male breast cancer in the family
  • An immediate relative with multiple kinds of cancer

For More Information

If you are concerned about your risk for hereditary breast cancer, call 214-645-2563 to schedule an appointment with a UT Southwestern board-certified genetic counselor. You can also learn more by visiting the Cancer Genetics area of www.simmonscancercenter.org