Running in the family

Screening for inherited cancer risk can save lives —
so why are FPs so reluctant to order the genetic tests?

By Armen Tamzarian

"It doesn't surprise me that many family doctors feel they lack the skills," says Dr June Carroll, associate professor of Family Medicine at the University of Toronto and family physician at Toronto's Mount Sinai Hospital, of recent US findings that family physicians shy away from screening for inherited cancer due to lack of confidence in their screening skills. "We did a qualitative focus group study with family physicians in Ontario and found similar results."

The US study, in the current issue of Annals of Family Medicine, was carried out by Dr Robert Gramling and colleagues who measured the attitudes of 300 members of the Massachusetts Academy of Family Physicians about genetic cancer screening. They found that 87% of FPs believed genetic cancer screening to be important, but less than 62% thought they were effective in screening their patients for hereditary cancer.

"These tests are relatively new and medical schools are just coming up to speed with this," explains Dr Carroll. "I personally feel confident in identifying people with increased risk, but this is my area of interest and I'm involved in developing the necessary tools."

For Dr David Hogg, a cancer geneticist at the Princess Margaret Hospital in Toronto, genetic cancer screening is no easy task to take on and training is only the beginning. "It's definitely a difficult process. Genetics teaching in medical school is very poor and learning the process takes a lot of training," he says. "Unfortunately, most family doctors don't get that training."

Screening for inherited cancer involves taking an account of a patient's family history and recognizing specific cases that may need further evaluation. Training for this procedure requires a few steps, says Dr Carroll. She believes the role of the family doctor right now is limited to identifying high-risk families and offering referrals.

"The tests can be ordered by family doctors but this isn't being done because you need accurate pathology results and a lot of counselling for the patient," she says. "Most doctors prefer sending their patients to a geneticist for such procedures."

WHAT'S AT STAKE?
Cancer will kill about 68,000 Canadians this year, according to the Canadian Cancer Society — about five to 10% of these cancers are hereditary. Most cancers develop as a result of changes in specific genes, known as gene mutations, and these can be inherited from a parent, increasing the risk of developing cancer.

"Mutations that are found in the germ line as opposed to those occurring in individual cells, have the ability to pass through generations," says Dr Hogg, whose work is a combination of clinical and research activity in cancer, with a special focus on melanoma.

He says that out of an estimated 100 families, at least 10 will have a history of cancer. Of those 10, three will have a strong family history and therefore a high-risk of developing cancer. "It's really important to identify families with high-risk because we can prevent disease and possibly death."

On the other side of the coin, inherited cancer screening can come with some rather undesirable baggage , most importantly concerns about accuracy. "It's important for doctors to educate their patients properly because genetic testing can be misleading," says Dr Carroll. "The results of such tests are not always 100% accurate — but it's like that with all new technologies." That said, she does believe there's a strong movement in Canada to get the right tools out there for family doctors.

Another issue family doctors have with cancer screening is the emotional consequences for their patients knowing they may be at risk, and weighing up the benefits and drawbacks. "Family doctors don't want to harm their patients in any way," says Dr Carroll. "They definitely see a future in screening, but they are patient advocates and they really want to see if they have all the information necessary to reassure their patients about genetic testing."