To Screen is Human
Smack in the midst of October-is-breast-cancer-awareness-month, the Journal of the American Medical Association published a provocative article with a low-key title: “Rethinking Screening for Breast Cancer and Prostate Cancer.” The authors examined trends in screening, diagnosis and deaths from cancer over two decades, applied theoretical models to the data and found a seemingly disappointing result.
It turns out that standard cancer screening is imperfect.
The subject matters, especially to me. I’m a medical oncologist and a breast cancer survivor, spared seven years ago from a small, infiltrating ductal carcinoma by one radiologist, an expert physician who noted an abnormality on my first screening mammogram.
The New York Times featured the new findings in a front-page article that elicited over 200 readers’ comments. Quite a few cheered the frank, non-party line that mammography‘s not all it’s cracked up to be. Same goes for measuring the prostate specific antigen in men’s blood, a test that sometimes marks for prostate cancer.
Some readers connected the dots between cancer screening, the pharmaceutical industry and physicians’ income. Because doctors make money by interpreting scans, doing biopsies and giving chemotherapy, perhaps they can’t be trusted to make unbiased recommendations. Like an aggressive tumor, the story spread everywhere – cable news, NPR, a host of blogs.
Fear, hassle, insurance forms (if you’re lucky), blood tests, anxiety, CAT scans, possibly a cancer diagnosis with attendant surgery, radiation, chemotherapy, nausea and who knows what else ensues. Yuck. The toll is huge, even apart from the finances.
The Food and Drug Administration estimates that radiologists perform some 37 million mammograms each year in the United States. Women undergo 70 percent of those scans for routine screening purposes. (Doctors order the other 30 percent to evaluate lumps or other signs of cancer that’s already evident.) My math: that’s 26 million screening mammograms at, roughly, $100 per scan, for a total cost of $2.6 billion annually.
Compounding the confusion, a few days later the Times ran a related piece highlighting reports that some tumors shrink or even disappear without treatment. That’s wonderful news, if it’s true. Perhaps you can skip the mammogram, not find the cancer, and it’ll just go away.
This represents a form of wishful thinking. Reality check in three points:
1. Prostate cancer is not the same as breast cancer. You can’t simply lump these together in a study and draw conclusions about testing or treatment for either condition.
2. Breast cancer is a common and very real cause of death in North America, where each year there are nearly 200,000 new cases and more than 40,000 associated deaths.
3. Mammograms save lives by uncovering tumors when they’re still small enough for surgical removal.
In 2009, there is no known cure for metastatic breast cancer. A woman’s chances of surviving for five years after she’s found to have a small, localized tumor lie in the 98 percent range; if she’s noted with metastatic disease, those odds hover around 25 percent.
So what’s a woman to do?
Sure, it’s discomfiting to know that screening doesn’t always work. And for some, it’s disheartening that doctors, insurance companies and x-ray machine makers generate profits by detecting, evaluating and treating cancer. In case you haven’t been following the health care reform debate, health care’s an imperfect business.
Many will continue to go for annual mammograms, especially in October, and their doctors will, emphatically, recommend that they get those. And many men will request of their internists, or urologists, or whoever’s taking care of them, that they get a blood test for prostate cancer, “just to be sure.” Likely, a few more skeptics will opt out of the screening process.
Screening for breast and prostate cancer could be better. The same applies to pretty much everything in health care, as in any human enterprise. But it’s the best that we’ve got, for the time being.