Genetic Testing and Preventative Surgeries
- 24-year breast cancer survivor Susan Berger decided to have a mastectomy, ovary removal and fallopian tube removal after testing positive for the PALB2 gene mutation and doing extensive research on the lesser-known mutation for a New York Times article. The PALB2 mutation can increase your risk for breast, ovarian and pancreatic cancer.
- Genetic testing can help predict an individual's cancer risk by looking at inherited gene mutations. These results can provide potentially life-saving information for patients who test positive for known mutations and who then can undergo preventative screenings or specific treatments for cancer.
- Women must weigh the pros and cons of cancer-prevention surgery in consultation with their doctors.
Berger was diagnosed with breast cancer in 1997 after a routine mammogram. Her treatment consisted of a lumpectomy, six months of chemotherapy, six weeks of radiation and later 10 years of the drug tamoxifen. Then, in 2009, she had genetic testing done and was delighted to hear that she did not have a BRCA mutation because BCRA1 and BCRA2 are genes that work as tumor suppressors and mutations of these genes put women at a higher risk for breast, ovarian and pancreatic cancer.
Read MoreThe PALB2 gene, referred to as the partner and localizer of the BRCA2 gene, provides instructions to make a protein that works with the BRCA2 gene protein to fix damaged DNA and stop tumor growth.
Berger was determined to learn more about PALB2 and share her knowledge, so she began researching the lesser-known gene mutation in May. In August, she published “Doctors Warn of a Lesser-known Breast Cancer Risk” in The New York Times.
After learning more about the mutation, Berger decided to have “her ovaries and tubes removed” in July, consulted a pancreatic cancer specialist (also because her grandmother died of pancreatic cancer so she was already at a higher risk) and talked with her doctor about the possibility of breast surgery.
Berger decided to have a prophylactic (preventative) mastectomy after her oncologist told her:
- A recurrence of her breast cancer could be estrogen negative as opposed to her previous estrogen positive cancer which is generally easier to treat.
- 10 years of tamoxifen would not protect her for a lifetime. In fact, he said the benefits probably ended after 15 years which would have been nine years ago.
- Not all cancers are caught via screening techniques.
“Rather than wait for a recurrence and then have a mastectomy, I would rather be proactive,” Berger wrote. “My breasts have served me well and nursed three daughters. I would rather eliminate the risk and have concluded knowledge is power.”
Understanding Genetic Testing
The most common gene mutations are the BRCA1 (BReast CAncer gene 1) and BRCA2 (BReast CAncer gene 2) mutations. It’s important to note that if a parent carries a BRCA gene mutation, there's a 50-50 chance you could be carrying it too.
Dr. Julie Rani Nangia, an assistant professor at Baylor College of Medicine, tells SurvivorNet about 10 percent of patients who undergo genetic testing will test positive for the BRCA1 or BRCA2 gene, but an additional 5 to 6 percent will test positive for other genes.
Other gene mutations that can lead to inherited breast cancer outside of PALB2 and the BRCA genes include ATM, TP53, CHEK2, PTEN, CDH1 and STK11. These gene mutations, however, are much less common and most of them don't increase the risk of breast cancer as much as the BRCA and PALB2 mutations.
And for cancers like pancreatic and ovarian cancer that can have very hard to spot symptoms, genetic testing can sometimes lead to an earlier diagnosis which generally means better treatment outcomes. Dr. Anirban Maitra, the co-leader of the Pancreatic Cancer Moon Shot at MD Anderson Cancer Center, previously told SurvivorNet that the prognosis for pancreatic cancer is not always good adding that around 53,000 patients get pancreatic cancer in the United States every year.
“By the time individuals walk into the clinic with symptoms like jaundice, weight loss, back pain or diabetes, it's often very late in the stage of the disease,” Dr. Maitra said. “And, unfortunately, most will die from this disease within a few months to a year or so from the diagnosis.”
But genetic testing can provide people with greater knowledge to work with when considering their risk for the disease.
“If you're concerned about pancreatic cancer in your family, start by talking to a genetic counselor to learn more about your risk and what options you have,” Jessica Everett, a genetic counselor at NYU Langone's Perlmutter Cancer Center, said.
Genetic testing can be used in cases like Susan Berger’s for preventative measures, but it can also be very helpful in navigating treatment options after a cancer diagnosis. With ovarian cancer, for example, BRCA 1, BRCA 2, PALB2, ATM gene mutations can point doctors toward PARP inhibitors which work by preventing cancer cells from repairing their own damaged DNA.
Genetic Testing Can Help Guide Ovarian Cancer Treatment Decisions
"Certain individuals with ovarian cancer, if they proceed with genetic testing and they test positive in specific genes, they might benefit the most from having PARP inhibitor medicine prescribed for them as treatment for their ovarian cancer," says Lauren Mills, a genetic counselor at UT Health San Antonio, adding that women who test negative for mutations in these specific genes may also benefit from PARP inhibitors.
Overall, genetic testing can be a great way to better understand your risk of developing certain cancers as well as best potential treatment options if you’ve been diagnosed with a certain cancer.
What to Consider with Preventative Surgeries
One thing to keep in mind when it comes to preventative surgeries like mastectomies and oophorectomies (ovary removal surgeries) is that these surgeries also have risks of their own and may not be the right choice for everyone.
Prophylactic Mastectomy For High-Risk Women
“Absolute risks are quite different from relative risks,” Dr. Elizabeth Comen, a medical oncologist at Memorial Sloan Kettering Cancer Center, previously told SurvivorNet. “A bilateral mastectomy is a forever decision one never gets their breasts back and there can be complications from surgery both short-term and long-term … there are many women who would say 'I can't handle the emotional and potentially physical consequence of any increased risk, not worth it to me, and I'm OK with never having breasts again.'”
Still, Dr. Comen noted that it is not yet known who will benefit from breast removal when it comes to these moderately risky gene mutations.
"It is essential that doctors help patients understand what their individual breast cancer risks may be based on specific mutations and other factors,” Dr. Comen said. “And perhaps most importantly, it is critical that doctors and patients explore how the emotional experience of that uncertainty informs surgical decisions.”
The Pros and Cons of Prophylactic Surgery for Ovarian Cancer
Barbara Dehn, a nurse practitioner at El Camino Women's Medical Group, also echoed that conversations with your doctor are key.
“What we know is when a woman has a genetic mutation that puts her at higher risk for developing ovarian or breast cancer, she has a lot of choices,” Dehn previously explained for SurvivorNet. “She does not have to automatically go to surgery… She might decide to freeze her eggs. She might decide that she’ll have surgery after 35 and after maybe having one or two pregnancies and breastfeeding her babies. She might decide to wait until she’s 40. There’s no one right way to go about this if you’ve been diagnosed with a BRCA1 or 2 mutation.”
Overall, Dr. Comen insisted that there’s a need for continued research.
“More work needs to be done to help refine our advice to individuals with increased risk of cancer so that we can help them make more precise decisions,” Dr. Comen said.
Learn more about SurvivorNet's rigorous medical review process.
