What These Sisters Want You To Know About Hereditary Brain Tumors

In the '80s, Carrie Davis and Hadley Davis Rierson lost their paternal grandmother to glioblastoma, a rare type of brain tumor that grows in the glial tissues of the brain.

"We thought that lightning struck once, because it is so rare," says Carrie Davis, 44, chief communications officer of Live Nation Entertainment in Los Angeles. "There was no reason to think that it would happen again in our family." So, they went on with their lives until 2013, when their father was diagnosed with glioblastoma. He died a year later at 70. "We thought, this can't be a coincidence," she says.

Indeed, in 2014, a study came out of Baylor College of Medicine determining the first genetic link associated with this type of glioma. "Hadley and I, being the people we are, we don't generally take no for an answer," Carrie says. "We had a very strong hunch that this had to be related." So, they reached out to the study author, who confirmed what the sisters suspected. Finding the one expert who understood what they had been through and could shed light on this disease was reassuring. "On the other hand, it was also terrifying to have this information," Hadley Davis Rierson, 47, a screenwriter in Los Angeles, adds.

Each year, about 22 thousand brain tumours are diagnosed in the United States. An estimated 5% of those cases (roughly 1,100) would have a familial predisposition. Unlike other cancers that are associated with genetic mutations, such as breast cancer, the number of glioma cases remains fortunately relatively small, explains Melissa Bondy, PhD, MS, professor in the department of medicine, epidemiology and population sciences, at Baylor College of Medicine, who leads the largest multi-national family study of glioma patients, called Gliogene. "We haven’t gotten to the point in brain tumours where we can identify a chain or multiples that are associated with the development of brain tumours," she says. Studies like Dr. Bondy's are crucial for helping to establish where these familial connections exist in the first place.

For people like the Davis sisters, who have lost three family members to glioma (in 2017, their father's sister also passed away from glioblastoma), diving headfirst into the research and community has been a coping mechanism. "There is power and also solace in seeking knowledge," Hadley says. Carrie adds that the three losses felt like a gut punch. "You can sit around and feel sorry for yourself that there's some genetic inheritance that we don't know about, or you can try and move things forward for the sake of your children, and their children who will also have our genes," she says.

A glioblastoma diagnosis can affect a person's sense of self, says David Arons, chief executive officer of the National Brain Tumour Society. "It changes people’s lives — it can create degenerative brain disease — and so it's really a disease that we all need to fight," he says. Unfortunately, there aren't preventative measures or anything in the realm of early detection that people can do proactively to take steps to prevent a brain tumour from occurring, he says. But if you are someone who has family members who have had brain tumous, then it's a good idea to stay informed about new research and advancements. (The National Brain Tumour Society also has helpful resources and support groups for people who are living with brain tumours.) Currently, the Gliogene study is seeking families who are facing hereditary glioma to participate in the study. "It's only through research that we can provide quality information," Dr. Bondy adds.

Overall, it's important for young women to be empowered and aware of your health issues and family history — whether it's brain tumour risk or another form of cancer — so you can monitor and know what you might be at risk of developing, Dr. Bondy says. "Knowledge is really important and the more we know the better we can manage our own lives," she says.

The Davis sisters have a similar message: "People should trust their gut and trust their instincts," Hadley says. "Nobody knows your family story better than you do."