Breast cancer gene screening is all the rage these days, but women who think they can rest easy if they're told they don't carry one of the two gene mutations—BRCA1 or BRCA2—should think again. Family history plays a prominent role in predicting breast cancer risk even in the absence of these mutations, according to new research presented at the American Association for Cancer Research meeting. In fact, a strong family history can increase your risk of breast cancer by nearly four times, giving you a 30 to 40 percent lifetime risk of breast cancer compared with the average woman's 12 percent risk.
What's meant by a "strong family history"? The study researchers defined it as having two or more first-degree relatives (mother, sister, daughter) who were diagnosed with breast cancer before age 50 or having three or more close relatives who were diagnosed at any age. So I wouldn't fall into this category even though my grandmother and her two sisters died of breast cancer. If you do, you might want to consider visiting a high-risk breast cancer center. And you might want to ask your doctor about more aggressive screening and preventive measures, according to lead study author Steven Narod, a senior research scientist at the University of Toronto. These include:
* Tamoxifen. Antiestrogen medications like tamoxifen or raloxifene can lower your risk of breast cancer from 40 percent to 20 percent. Caveat: Tamoxifen puts you into menopause (at least while you take it), so it's not a good option if you're planning to get pregnant. Raloxifene is approved for postmenopausal women only.
* Breast Screening MRI. This imaging test is far better at detecting tumors in dense breast tissue, which is typically found in premenopausal women. Your doctor may want to start this screening a decade before the age when your family members were diagnosed with breast cancer, say, at age 30 if your mother was diagnosed at age 40. Realize, though, that this test is extremely sensitive, which means you may have a biopsy for an abnormality that turns out to be benign.
* Prophylactic Mastectomy. Having your breasts surgically removed to prevent breast cancer is probably uncalled for, though Narod says some women may want to consider that option. It has been shown to slash breast cancer risk by nearly 90 percent.
The following lifestyle measures can lower your breast cancer risk or help detect breast cancer early, regardless of your family history or gene status.
* Healthy Body Weight. Body fat churns out estrogen, and excess fat around the abdomen causes hormonal changes that make breast tissue more vulnerable to estrogen's detrimental effects. Aim for a body mass index of below 25 (145 pounds for a 5-foot-4 woman) and a waist circumference of no more than 35 inches.
* Regular Mammograms. A yearly mammogram after age 40 is a must. While this screening tool is far from perfect, it has been shown to lower breast cancer mortality by 30 percent.
* Avoiding Alcohol. While alcohol's estrogen-boosting effect confers benefits to the bones and heart, recent research shows that compared with nondrinkers, those who consumed one to two drinks daily had a 32 percent greater risk of breast cancer and that those who had three or more daily drinks had a 51 percent greater risk. Previous studies have shown this association as well. Better to stick with just a few drinks a week.
* Exercise. New research shows vigorous activity cuts breast cancer risk by 30 percent. Being active for at least 30 minutes on most days of the week—scrubbing floors, raking leaves, brisk walking—can lower levels of blood estrogens, cutting off the fuel that makes many breast tumors grow.
If you've already been diagnosed with breast cancer, here's how to lower your risk of recurrence through lifestyle or medication.
Corrected on 12/01/08: An earlier version of this post incorrectly implied that raloxifene is prescribed to premenopausal women. It's approved for prevention in postmenopausal women only.