Did Drinking Give Me Breast Cancer?

I thought I’d done everything right: breastfeeding my children, a careful diet, plenty of exercise. I wasn’t overweight and didn’t have a family history. I bought BPA-free bottles for my filtered water. But on a visit to the radiology department last spring, a pair of red brackets highlighted something worrisome on the ultrasound monitor. Invasive lobular carcinoma—a malignant breast tumour. This spidery little beast measuring nearly three centimetres meant I had stage 2 cancer. At 47, I was a decade and a half younger than the median age for breast cancer diagnosis in the United States. Was this just bad luck? Maybe, but the journalist in me was still curious to know: Why me? So, I dug into the literature on risk factors to see where I might have fit in. It’s an impossible question to answer definitively for an individual, like trying to prove that a single weather event was caused by climate change. As one doctor told me, “You know who’s at risk for getting breast cancer? People with breasts!” Still, most of the broad indicators didn’t seem to apply to me. The biggest one is age: The median diagnosis in the United States is at 62, and the highest breast cancer rates are in women older than 70. Another is taking hormone replacement therapy after menopause, but I’m premenopausal and haven’t taken it. Obesity raises risk, but I’ve never been overweight. Then I saw one that gave me pause: alcohol consumption. I’m not a heavy drinker, but like most women I know, I have consumed a lot of alcohol in my lifetime. While doctors have frequently admonished me for putting cream in my coffee lest it clog my arteries—a correlation that’s been pretty thoroughly debunked—not once has any doctor suggested I might face a higher cancer risk if I didn’t cut back on drinking. I’d filled out dozens of medical forms over the years asking how much I drank every week, but no one ever followed up other than to say with nodding approval, “So you drink socially.” I quickly discovered that way back in 1988, the World Health Organization declared alcohol a Group 1 carcinogen, meaning that it’s been proved to cause cancer. There is no known safe dosage in humans, according to the WHO. Alcohol causes at least seven types of cancer, but it kills more women from breast cancer than from any other. The International Agency for Research on Cancer estimates that for every drink consumed daily, the risk of breast cancer goes up 7 percent. The research linking alcohol to breast cancer is deadly solid. There’s no controversy here. Alcohol, regardless of whether it’s in Everclear or a vintage Bordeaux, is carcinogenic. More than 100 studies over several decades have reaffirmed the link with consistent results. The National Cancer Institute says alcohol raises breast cancer risk even at low levels. I’m a pretty voracious reader of health news, and all of this came as a shock. I’d been told red wine was supposed to defend against heart disease, not give you cancer. And working at Mother Jones, I thought I’d written or read articles on everything that could maybe possibly cause cancer: sugar, plastic, milk, pesticides, shampoo, the wrong sunscreen, tap water…You name it, we’ve reported on the odds that it might give you cancer. As I schlepped back and forth to the hospital for surgery and radiation treatments, I started to wonder how I could know about the risk associated with all these other things but not alcohol. It turns out there was a good reason for my ignorance. I was born and raised in Utah, and after my cancer diagnosis, I wondered what would have happened if I’d stayed put. My home state has one of the lowest rates of breast cancer in the country. Observant Mormon women don’t drink, and like other populations that abstain, they have significantly lower rates of breast cancer than drinkers. In Utah, Mormon women’s breast cancer rates are more than 24 percent lower than the national average. (Mormon men have lower rates of colon cancer, which alcohol can also cause.) Researchers suspect the low overall rate of breast cancer in Utah has to do with the LDS church’s strict control over state alcohol policy. Gentiles, as we non-Mormons are called, grouse mightily over the watery 3.2 percent beer sold in Utah supermarkets, the high price of vodka sold exclusively in state-run liquor stores, and the infamous “Zion Curtain,” a barrier that restaurants were until recently required to install to shield kids from seeing drinks poured. Yet all those restrictions on booze seem to make people in Utah healthier, Mormon or not, especially when it comes to breast cancer. Epidemiologists first recognised the connection between cancer and alcohol consumption in the 1970s. Scientists have since found biological explanations for why alcohol is carcinogenic, particularly in breast tissue. When you take a drink, enzymes in your mouth convert even small amounts of alcohol into high levels of acetaldehyde, a carcinogen. People who consume more than three drinks a day are two to three times likelier to contract oral cavity cancer than those who don’t. Alcohol also damages the cells in the mouth, priming the pump for other carcinogens: Studies have found that drinking and smoking together pose a much higher risk of throat, mouth, and oesophageal cancer than either does on its own. Alcohol continues its trail of cellular damage as enzymes from the oesophagus to the colon convert it into acetaldehyde. The liver serves as the body’s detox centre, but alcohol is toxic to liver cells and can scar the organ tissue, leading over time to cirrhosis, which raises the risk of liver cancer. Researchers estimate that alcohol accounts for 15 percent of US breast cancer cases and deaths. As acetaldehyde courses through the body, it can bind to DNA, causing mutations that can lead to cancer, particularly in the colon. Alcohol is suspected of inflicting a double whammy on breast tissue because it also increases the level of oestrogen in a woman’s body. High levels of oestrogen prompt faster cell division in the breast, which can lead to mutations and ultimately tumours. Researchers estimate that alcohol accounts for 15 percent of US breast cancer cases and deaths—about 35,000 and 6,600 a year, respectively. That’s about three times more than the number of breast cancer cases caused by a mutation of the BRCA genes, which prompted Angelina Jolie, who carries one of the abnormal genes, to have both her healthy breasts removed in 2013. The breast cancer risk from alcohol isn’t nearly as high as the lung cancer risk from smoking. But alcohol-related breast cancer kills more than twice as many American women as drunk drivers do. And alcohol is one of the few breast cancer risk factors women can control. Others, like starting menstrual periods before the age of 12 and entering menopause after 55, are baked in. Overall, American women have about a 12 percent lifetime risk of getting breast cancer. Walter Willett, an epidemiology professor at the Harvard T.H. Chan School of Public Health who has conducted studies on alcohol and breast cancer, says a woman who consumes two to three drinks a day has a lifetime risk of about 15 percent—a 25 percent increase over teetotalers. By comparison, mammography reduces the death rate from breast cancer by about 25 percent. “Alcohol can undo all of that at about two drinks a day,” Willett says.

Mother Jones, May/June Edition ; http://www.motherjones

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