Ask the Doctor: May 2008

Question: I am 45 and I see my gynecologist and get my mammogram every year. I have been hearing recently about other ways to screen for breast cancer, like ultrasound and MRI? Should I be getting these tests as well as my mammogram?

Answer: The gold standard for breast cancer screening is still a yearly mammogram after age 40, so I am glad that you are getting yours each year. The ultrasound and MRI are used to improve the sensitivity of the mammogram for women with higher risks and lumps that we can feel on exam. If you, or your doctor, find a lump on the breast exam, you should have an ultrasound to determine if the lump is a cyst or a solid mass.

Rarely, a breast cancer is not seen on mammogram, but can be picked up on ultrasound, especially if your breasts are dense. Breast MRI is currently recommended for a specific group of high risk women. The evidence has not yet proven that it gives any advantage over mammogram in a normal risk woman.

The American Cancer Society guidelines for breast MRI are for women who test positive for the genes BRCA1 and BRCA2. They also recommend breast MRI for women who have a first degree relative (mother, sister, or daughter) who tested positive for BRCA1 or BRCA2, even if the patient has not been tested themselves. Women who carry a lifetime risk of breast cancer of 20-25% based on family history and other factors are candidates for breast MRI. Women who had radiation to the chest between ages 10 and 30 are at higher risk of breast cancer and should also be screened with breast MRI. These women should also continue to have routine mammograms.

Question: My mom and her sister both had breast cancer in their 50s. I am 36. Should I be tested for the breast cancer gene?

Answer: This is a difficult question to answer, because everyone’s risk is different, and only 10% of patients with breast cancer also have a family history of breast cancer, and not all patients with a family history carry the breast cancer gene.

There are two known genes that increase the risk of breast and ovarian cancer, BRCA1 and BRCA2. Testing involves a blood test that can be very expensive and not all insurance companies will cover the cost of testing.

The other issue with the breast cancer genes is that they only increase the risk of getting breast or ovarian cancer; they do not guarantee that a patient who tests positive will get those diseases. Testing positive for either gene will increase the risk of developing breast cancer to a 36-85% lifetime risk, and the risk of developing ovarian cancer to a 16-60% lifetime risk. The large range of risk is due to the information we get from the different studies of women with positive genetic tests, and accounts for the other factors in developing breast cancer including environmental factors.

It is generally recommended that the family member with breast cancer be tested for the genes first, in your case it would be your mom. If she tests positive, you can decide if you want to be tested. If she is negative, then you do not need to be tested.

I recommend genetic counseling by a gene specialist or oncologist before deciding whether or not to be tested. I also recommend careful consideration of your early detection and prevention options if you are positive. Early detection is the most important for the survival rates of breast cancer. As I discussed in the previous reader’s question, you should get a breast MRI and possibly more frequent mammograms and clinical breast exams. You must also consider the increased risk for ovarian cancer and you may chose to screen more aggressively with a yearly pelvic ultrasound and the CA-125 blood test.

The other option is to surgically remove as much of the breast or ovarian tissue as possible with a mastectomy and/or oophorectomy to prevent the cancers. This would be done before you ever show signs of cancer. This is the most effective way of preventing breast or ovarian cancer if you are very high risk. However, it is not a guarantee you won’t develop cancer and it is a very difficult, life changing decision and should not be made without the appropriate counseling.

You may also choose to take tamoxifen to prevent developing breast cancer. Tamoxifen is a drug previously only used for patients who have survived breast cancer to help prevent recurrence, but is now used to prevent breast cancer in high risk women. Tamoxifen is not without side effects and needs to be discussed as one of your options in your pre-testing counseling.

For more information about genetic testing and breast MRI you can visit the American Cancer Society’s website at www.cancer.org or call the National Cancer Institute’s information line 1-800-4- CANCER (1-800-422-6237).

Dr. Karen Lockwood is a graduate of University of Oklahoma College of Medicine.  She completed her residency in Internal Medicine at Henry Ford Hospital in Detroit.  She is board-certified in Internal Medicine and is currently in private practice in Troy, MI.

If you would like to submit a medical question to Dr. Lockwood, Please email your question to askthedoc@healthandleisureonline.com.

*Advice found within this article is for informational purposes only and should not replace the advice or recommendations of your physician.