Mark Meerschaert knows this only too well. The Michigan State University statistics professor learned that he carried a BRCA2 mutation after he was diagnosed with prostate cancer in 2013 — but the news was no shock. One of his male relatives had already tested positive for mutated BRCA2 after developing breast cancer a few years earlier.
“When medical oncologists look at my family history, they usually all have the same reaction, which is, ‘Well, that’s a typical BRCA2 family tree,’” Meerschaert said. Meerschaert’s father and nearly all of his father’s 11 brothers and sisters experienced some form of cancer.
Because hobbled DNA-repair genes raise the risk of so many cancers, Montgomery and Cheng hope that if a man tests positive through the GENTleMEN study, his family members will also get tested. Then, they’ll have a better sense of their own cancer risk and what steps could safeguard their future health. The genetic counseling offered through the study can help men weigh their options.
Meerschaert encouraged his family members to find out if they carry the same mutation. If he’d known about his BRCA2 status earlier, he said, he might have undergone more stringent screening to catch potential tumors earlier. Confronted with the risk of other cancers, he includes screening steps, such as breast self-exams, that would never have occurred to him previously.
“I don’t understand why someone wouldn’t want to know, Meerschaert said. Now, many members of his family have learned that they also carry the same cancer-predisposing variant of BRCA2.
Tailoring treatment
As Meerschaert learned, testing positive for a DNA-repair mutation can lead to more targeted treatment. After an initial course of chemotherapy, his prostate tumor melted away — but then recurred in July 2016. Within the tumor, the normal copy of BRCA2 that Meerschaert had inherited from his mother had also been mutated. Meerschaert’s health declined quickly.
Meerschaert was an avid runner who was also in the midst of arranging an international scientific conference. “I was running three miles a day. Within three months [of my cancer recurrence], I couldn’t even stand for five minutes,” he recalled.
Now a patient of Cheng’s, Meerschaert is taking a type of chemotherapy known as a PARP inhibitor, a type of drug to which tumors with DNA-repair mutations are particularly sensitive. Already approved for advanced ovarian cancer, PARP inhibitors are still being tested against advanced prostate cancer, but Cheng and other researchers are excited about their potential.
Men who participate in the GENTleMEN study could well be steered toward a clinical trial similar to the one Meerschaert is in, said Cheng and Montgomery. But there are other drugs, already available and in use against certain subtypes of prostate cancer, that could benefit men with DNA-repair mutations. Patients could receive them from their local oncologists.
The possibility that a patient who tests positive for certain DNA-repair mutations will respond well to such drugs is “not theoretical,” said Cheng. “It’s very likely to be true.”
On his experimental therapy, Meerschaert has bounced back — from standing to walking, walking to occasional running. Though he’s selective about how he spends his now more-limited energy (and makes sure to maintain his health with a daily two-hour nap), Meerschaert said he has plenty with which to enjoy his life.
Removing barriers
Once they’d established the link between inherited DNA-repair mutations and aggressive prostate cancer, Nelson, Pritchard and their team pushed for modifying screening guidelines for men with advanced prostate cancer. As a result, the National Comprehensive Cancer Network guidelines now recommend that men with metastatic prostate cancer receive testing for such mutations. But getting the testing and information to men who are eligible is another matter.
Cheng’s GENTleMEN study removes two of the largest barriers, said Montgomery: getting access to genetic counseling and getting approved for coverage of genetic testing.
The web-based, long-distance nature of the study could be the key to providing men access to this kind of care, regardless of where they’re located. One of the study’s goals is to assess how well a web-based approach works, said Cheng. In addition, they’ll try to build a full picture of the patients participating, including their family history and knowledge about these mutations. To do this, the team is building on prior work in other cancer fields.
“We know from breast and ovarian cancer that [web-based genetic counseling is] a reasonable option given that there are limited resources with genetic counselors in person,” she said.
And for those men who test positive for a DNA-repair mutation that is known to carry cancer risk, insurance generally covers face-to-face genetic counseling, Montgomery said.
A first step toward more knowledge
Researchers in Seattle have spent many years carefully parsing different DNA-repair mutations and risks associated with breast and ovarian cancer, but the strength of those links to prostate cancer are only starting to be appreciated, Montgomery said.
“We’re in the Dark Ages compared to breast and ovarian cancer and really understanding which mutations raise the risk and by how much,” Nelson said. The GENTleMEN study is a first step toward gathering the information researchers need to paint a fuller picture of men’s cancer risk and appropriate preventive measures, he said. More studies are in the works by the cross-institutional prostate cancer research team at Fred Hutch and UW to begin addressing these questions.
And although the work already has resulted in changes to the NCCN guidelines, it will take time to translate these into changes in practice and insurance reimbursement, Nelson said.
Even as they look to the future, Cheng and Montgomery want the GENTleMEN study to make a difference in men’s lives now.
“We’re really invested in anybody anywhere who could know about this [trial] and have it make a difference,” Montgomery said.
The GENTleMEN study is supported by the Fred Hutch-UW Institute for Prostate Cancer Research and the Color Foundation.