Breast cancer test not for all women, say experts

While women are being widely urged to undergo breast cancer screening, experts from the University of Michigan have warned that the test is not appropriate for all women.

A genetic mutation has been found to significantly increase a woman's risk of developing breast cancer and ovarian cancer.

However, experts estimate only 2 percent of the population should be tested for the mutations, which occur in genes called BRCA1 or BRCA2.

"While the test is a very easy thing to do - it's a simple blood test - the interpretation of the results can sometimes be very complicated," said Dr Mark Pearlman, vice chair and professor of obstetrics and gynecology at the University of Michigan Medical School.

Women who inherit a mutation in these genes face a higher lifetime risk of developing breast and ovarian cancer, and cancer is more likely to develop at an earlier age.

Lifetime risk of breast cancer in these women jumps from 12.5 percent in the general population to approximately 60 percent in women with BRCA mutations. Lifetime ovarian cancer risk rises from 1.4 percent up to 40 percent for those with the mutation.

But most breast and ovarian cancers are random, and are not linked to the BRCA genes.

Fewer than 10 percent of all women with breast cancer carry one of the BRCA gene mutations and about 15 percent of women with ovarian cancer carry one of the mutations.

"It's very important that the right women seek out genetic testing for breast and ovarian cancer," said Dr Sofia Merajver, director of the Breast and Ovarian Risk Evaluation Program at the University of Michigan Comprehensive Cancer Centre.

"Cancer risk is more complex than a simple yes or no, and the test for genetic mutations is only part of the picture."

Doctors recommend genetic testing for those who have high numbers of family members with cancer diagnoses throughout several generations, either maternal or paternal, family member diagnosed with cancer before age 50, family members who have been diagnosed with multiple cancers (for example, breast and ovarian) and male breast cancers, or clusters of other cancers such as colon, prostate, stomach or pancreatic

"It's important to understand that getting the genetic test result is only a piece of the puzzle," said Pearlman.

"It really takes a professional who understands genetics to help work with individual women and men to allow them to understand exactly what that piece of information means to them in terms of their risk, their loved ones' risks and what can then be done to help lower that risk," Pearlman added.