A study suggests that primary care doctors don't consistently recommend genetic testing for women at high risk for cancer because of family and personal history.
The results were published online July 25, 2011 in the journal Cancer.
Most inherited cases of breast cancer are associated with one of two abnormal genes: BRCA1 (BReast CAncer gene one) or BRCA2 (BReast CAncer gene two).
Women with an abnormal BRCA1 or BRCA2 gene:
- have up to an 85% lifetime risk of developing breast cancer
- have a much higher-than-average lifetime risk of ovarian cancer; estimates range from 15% to 60%
U.S. guidelines say that BRCA testing should be considered when:
- many women in a family have been diagnosed with breast and/or ovarian cancer, particularly if the women were younger than 50 when diagnosed
- some women in a family have been diagnosed with cancer in both breasts
- there is both breast and ovarian cancer in a family
- men in a family have been diagnosed with breast cancer
- there is breast cancer in a family and either male relatives on the same side of the family have been diagnosed with prostate cancer at a young age or relatives on the same side of the family have been diagnosed with gastrointestinal cancers, such as pancreas, gall bladder, or stomach cancer
- a family is of Ashkenazi (Eastern European) Jewish descent
In this study, nearly 1,900 primary care doctors (family medicine, internal medicine, ob/gyn doctors) answered a survey about how they recommended genetic counseling and testing for women with average risk or high risk of cancer.
Only 41% of the doctors said they would refer women at high risk and eligible for genetic counseling based on U.S. guidelines to get this genetic counseling and testing.
The chances that a high-risk woman would be referred for genetic screening were affected by a number of factors:
- Age: A 35-year-old, high-risk woman would be referred by 57% of the doctors compared to 27% of high-risk women older than 50.
- Gender of the doctor: 50% of female doctors follow U.S. guidelines for genetic screening of high-risk women compared to 35% of male doctors.
- Doctor's specialty: Ob/gyn doctors are more likely to follow U.S. genetic screening guidelines; family medicine doctors are least likely to do so.
- Insurance: Genetic screening referrals are more likely if a high-risk woman has private insurance.
- Race: Genetic screening referrals are more likely among high-risk white women compared to high-risk black women.
- Ovarian cancer risk: Genetic screening referrals are more likely for women at high risk of ovarian cancer compared to women at high risk for breast cancer.
These results suggest that many high-risk women who should have genetic screening aren't having that screening done. This is troubling. Women with an abnormal breast cancer gene have a number of options to reduce breast cancer risk, as well as ways to detect any cancer that develops early, when it's most treatable. These risk reduction steps include:
- a more aggressive screening plan starting at an earlier age
- hormonal therapy to block the effect of estrogen on breast tissue or reduce the amount of estrogen in the body
- removing the healthy breasts (prophylactic mastectomy)
Some women with an abnormal BRCA1 or BRCA2 gene also may consider having healthy ovaries removed because of the increase in ovarian cancer risk. Removing the ovaries also dramatically lowers estrogen levels and lower estrogen levels can reduce the risk of hormone-receptor-positive breast cancer.
Knowing that a woman has an abnormal BRCA1 or BRCA2 gene also is important information for the other women and men in her immediate family to have; they also may be carriers and at a higher risk of cancer.
The Gail score is a standard breast cancer risk assessment tool that assesses breast cancer risk based on a series of personal health questions that women and their doctors answer together. The questions ask about risk factors such as age, child-bearing history, family history of breast cancer, and breast biopsy results. The Gail score estimates the risk of developing invasive breast cancer in the next 5 years. If you think you may be at high risk for breast cancer, you might want to talk to your doctor about your personal and family medical history. You also may want to ask your doctor to consider calculating your Gail score and then talk about what it means. You also may want to ask your doctor if genetic testing or a referral to a genetic counselor makes sense for you.
For more information, visit the Breastcancer.org Genetic Testing pages.