It's that time of the year again, when women are told to don pink and think about breast cancer. And, yes, we're thinking about it: An illogical but attention-grabbing Facebook breast cancer awareness campaign to get women to post "I like it on the floor/I like it on the couch" status updates—where they like to put their purse, not have sex—went viral this week. And thanks to the Susan G. Komen Foundation pink ribbon campaign, which first launched 25 years ago, we are much more aware now about the importance of early detection via mammograms and regular breast exams. (U.S. News is participating in a fundraising campaign for the foundation.) Yet many of those who are deeply engaged in research to find a breast cancer cure aren't happy with the way things are going. "I really don't feel like celebrating," wrote Fran Visco on Monday in this Huffington Post blog; she's president of the National Breast Cancer Coalition, a nonprofit organization that advocates for more research. "Twenty-five years ago, in the United States, 110 women died of breast cancer every day," she continued in her blog. "Twenty-five years and billions of private and public research dollars later, that number is 110. Every day. Not much progress, is it?" (She's right, but that doesn't take population growth into account. The death rate from breast cancer is about 15 percent below what it was in 1985.)
Breast cancer surgeon Susan Love expressed these same negative sentiments to me. She recently published the 20th-anniversary edition of her best-selling Dr. Susan Love's Breast Book. It's much thicker than it used to be, due to bulked-up chapters with new information on the science of breast cancer and the wider assortment of treatments. But, she tells me, the chapters on causes and prevention of the disease haven't changed that much over the past two decades. "There's frustration out there that we don't know more," she says. "We're wearing pink, walking and running to raise money for research, God knows we're aware, and yet we still don't really have a clue what causes this disease."
Sure, researchers now know that two inherited breast cancer gene mutations, BRCA1 and BRCA2, account for a small percentage of breast cancers. And lifestyle factors like age at first childbirth, body weight, amount of exercise, and alcohol intake play some role in determining a woman's risk. But 70 to 80 percent of those diagnosed with breast cancer, says Love, do everything right and have no gene mutations. I asked Love for her assessment of various hot-button issues pertaining to breast cancer.
Mammography. Women age 50 and over should be screened every year or two, Love says, since studies have consistently shown that screening on those over 50 reduces breast cancer deaths by 20 percent. Women ages 40 to 50 should discuss the risks and benefits of screening with their doctors, since the latest research shows more modest reduction in death risk and greater likelihood of false-positive results leading to biopsies of abnormalities that turn out not to be cancerous. All women, though, should realize that mammograms benefits have been oversold, says Love. The X-ray can find some, but certainly not all, tumors in the earliest stage, before they've had a chance to spread.
Environmental chemicals. A host of chemicals in pollutants, pesticides, and plastics have been blamed for triggering breast tumors, at least in cell cultures or animal studies. But researchers still don't know enough about the effects of these chemicals to tell us which ones to avoid altogether. While it's wise to be cautious and minimize exposure when possible, say by eating organic produce, Love says we also have to remember that humans aren't mice. "Soy was shown to increase breast tumors in mice," she points out, "but Japanese breast cancer survivors with the highest intake of soy foods have since been found to have a lower rate of recurrences."
New gene mutations. There are most likely other genes involved in breast cancer beyond the BRCA1 and BRCA2 mutations, but Love thinks it's doubtful that researchers will find new mutations that, like these two, lead to a dramatic increase in risk. Researchers may, though, still identify genes that indirectly lead to breast cancer by, for example, influencing how the body metabolizes estrogen, a female hormone the fuels the growth of some breast tumors.
Diet. The data aren't strong enough to make the case for a "breast cancer prevention diet," says Love. In general, a diet low in animal fat and rich in whole grains, fruits, and vegetables will help keep you healthy and thin. In fact, your body weight after menopause appears to be a more important predictor of postmenopausal breast cancer risk than the composition of your diet, she says. Maintaining a healthy weight after menopause will help keep your estrogen levels low since the hormone is produced by fat cells. Regular exercise can also reduce your risk somewhat. "Studies suggest women need to break a sweat for at least three hours a week to see some risk reduction," says Love. You might also want to curtail your consumption of alcohol; the latest research suggests that imbibing as little as a drink or two a day can raise breast cancer risk, although Love stresses that you should weigh this small increase in risk against the benefit—moderate drinking is good for your heart.
[Women and Alcohol: How Much is Healthful?]