Cancer Sunnybrook Magazine - Spring 2016

Unlocking prostate cancer’s genetic secrets

Justin Lorentz and patient

Justin Lorentz (left) is looking at how genetic mutations such as BRCA tend to affect certain ethnic groups, among other factors. (Photograph by Doug Nicholson)

“I’m told that I have the prostate of a 20- year old,” says 58-year old Martin S., “which is a great pickup line, except that I’m happily married.”

Martin’s prostate is the subject of more than a quirky pickup line.

Because he has a gene mutation associated with prostate cancer, Martin was invited to take part in the Male Oncology Research Program at Sunnybrook’s Odette Cancer Centre. He has BRCA2, which, along with BRCA1, is a gene mutation that can increase risk for prostate, breast and ovarian cancers. (For privacy, Martin asked that his full name not be used.)

The research program’s confidential registry, database and biobank for men with genetic dispositions for prostate cancer are a collaborative undertaking by several institutions that is led by Sunnybrook.

“Ancestry, family history and known genetic predispositions such as BRCA mutations are important factors in a risk assessment for prostate cancer,” says Justin Lorentz, a genetic counsellor at the Odette Cancer Centre. “We know that men of Ashkenazi Jewish ancestry are 10 times more likely to have a BRCA1 or BRCA2 gene mutation compared to men who are not of Ashkenazi Jewish ancestry.”

“Men of West African/Caribbean ancestry are also known to have higher risks for prostate cancer and more aggressive disease, and men with a family history of prostate cancer are known to be at increased risk,” adds Lorentz.

“We are actively working to engage men of West African ancestry or men with strong family histories, to better understand how prostate cancer is inherited and how best to support these patients,” adds Dr. Danny Vesprini, a radiation oncologist and researcher at Sunnybrook with a specific interest in the genetic predisposition to develop prostate cancer.

“One of our challenges is to get guys into the clinic to participate in this kind of research,” says Lorentz.

Martin, however, was glad to get involved. So far, he’s in good health with the prostate of, well, a 20-year-old. And he knows that not all men with BRCA mutations will develop cancer. Nevertheless, he explains, “my maternal grandmother died from breast cancer, my mother and an aunt died from breast cancer in their 40s. Until I had genetic counselling at Sunnybrook, I hadn’t realized the mutation could be passed on to sons and then passed on by them.”

More recently, research such as that ongoing at Sunnybrook has found that men with BRCA mutations carry up to double the risk for prostate cancer and are more likely to be diagnosed at an earlier age; in addition, the cancer is likely to be more aggressive compared to men in the general population who develop the disease.

“Prostate cancer is often slow-growing, though it can also be aggressive in men in the general population. In the case of men with BRCA mutations or other known genetic predispositions, and those with strong family histories (given their higher risk), we really want to monitor these guys closely for early diagnosis and timely intervention,” says Dr. Vesprini.

He strongly believes other mutations and markers will be found, most likely sooner rather than later. “We’ll likely find something heritable in families with strong family histories,” he says.

Sunnybrook is one of only a handful of hospitals researching men with known genetic predispositions like BRCA1 and BRCA2, and men with a strong family history of cancer or who are of West African/Caribbean ancestry.