In recent years, genetic counselors have seen increasing numbers of women seeking guidance as they consider being tested for possible gene mutations that could signal increased risk for developing the disease.

The results of such genetic tests, however, often will affect other family members as well, said Robert T. Pilarski, a genetics counselor at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute.

People often consider genetic counseling because they have discovered an unusual pattern of disease in their family or disease that has occurred at an unusually early age – two red flags that suggest counseling might be helpful.

Genetic testing – which is becoming increasingly popular – refers to analyzing DNA to look for a genetic alteration that may indicate an increased risk for developing a specific disease or disorder. Genetic susceptibility is an inherited increase in the risk of developing a disease. Genetic markers are alterations in DNA that may indicate an increased risk of developing a specific disease or disorder.

“We stress that this really is a family issue,” Pilarski said. “When someone tests positive for a genetic mutation, that has implications for the entire family. In such cases, we recommend that other family members have the genetic testing too, so that they will know which of them may need more careful screening in the future.”

Genetic testing can reveal whether a family has certain gene mutations that put them at greater risk for developing breast and ovarian cancer, Pilarski said.

“Only about 5 to 10 percent of breast cancer is hereditary, and part of our role is to help identify those patients to help save lives,” Pilarski said. “Women with a family history of breast cancer may have an increased risk for disease.”

Women who have tested positive for the BRCA1 and BRCA2 gene mutations are at greater risk for developing breast and ovarian cancer, he said. Mutation carriers are encouraged to start doing breast self-exams as teen-agers, and to start having mammograms at age 25, Pilarski said. Screenings for ovarian cancer – including a blood test and vaginal ultrasound – are also an option starting at age 30. Unfortunately, most studies show that ovarian cancer screening is not very effective, he said.

In some cases, women who have tested positive for gene mutations but have not been diagnosed with breast cancer decide to have mastectomies as a proactive measure, Pilarski said.

In addition, such women are encouraged to have their ovaries removed by age 40, or when they are finished having children, in an effort to prevent ovarian cancer from developing, he said.

During genetic counseling the person's family and personal medical history are discussed, and counseling may lead to genetic testing. Age-specific risk estimates are available to help counsel and design screening strategies for these women. Specific mutations of BRCA1 and BRCA2 are more common in women of Jewish ancestry.

The estimated lifetime risk of developing breast cancer for women with BRCA1 and BRCA2 mutations is 40 percent to 85 percent. Male carriers of BRCA2 mutations are also at increased risk for breast cancer. In addition, mutation carriers may be at increased risk of other primary cancers.

“It is critical to identify families with hereditary breast cancer, because knowing such information can make a tremendous difference in how they manage their risk for the disease,” Pilarski said.

The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute is one of the nation’s leading centers for research on the prevention, detection, diagnosis and treatment of cancer. The OSUCCC – James encompasses six interdisciplinary research programs and includes more than 200 investigators who generate over $100 million annually in external funding. It is a founding member of the National Comprehensive Cancer Network, and OSU’s James Cancer Hospital is consistently ranked by U.S. News & World Report as one of America’s best hospitals for cancer care.