Mammograms are a wonderful diagnostic tool for breast cancer. Except when they aren’t.
Every year, the U.S. spends $4 billion on unnecessary costs associated with mammograms, primarily due to the scans rendering “false positives” – that is, a false alarm signaling a problem when there isn’t one, or a problem so minor that it never will amount to a true medical concern.
As reported earlier this month by the Associated Press (AP), a study published in the journal Health Affairs found that $2.8 billion of those costs were the result of false positive mammograms, and $1.2 billion were from overdiagnosis of breast cancer – that is, treating tumors that were unlikely to develop into something serious over the course of the woman’s lifetime.
The costs pertained to women who had mammograms when they were 40 to 59 years old. The study used billing data from a major U.S. insurer and involved more than 700,000 women from all 50 states, from 2011 through 2013.
We’ve written many times about how mammograms to detect breast cancer, along with PSA tests to detect prostate cancer, are a double-edged diagnostic sword. Yes, they can detect true problems, but also minor issues and questionable things that are proved irrelevant only after the patient has undergone additional testing, additional risks (such as pain, infection, worry, etc.) and additional costs.
This study is simply the latest scientific evidence that our ability to detect interesting things in the body exceeds our ability to know if they are worth pursuing for the greater health good.
Breast cancer is the second most common cause of death from cancer among U.S. women; about 41,000 die from it every year. Until a few years ago, annual mammograms were recommended for women starting when they turned 40. Like most cancers, breast cancer is more likely to be treated successfully the earlier it is detected, but the standard annual mammogram has become, among many professionals, less “standard” because of its potential to cause more trouble than it might solve.
The new study pegs the cost of breast cancer overtreatment as much higher than previously estimated.
Still, plenty of practitioners support routine screening, and one called the study one-sided.
Richard Wender, head of prevention, detection and patient-support efforts at the American Cancer Society, questioned the study’s assumptions, calling them a “very selective choice of estimates” for the rates of false positives and overdiagnosis.
“There is no debate about the benefits of mammography,” he said.
The American Cancer Society continues to recommend annual mammograms for women starting at age 40, but the U.S. Preventive Services Task Force, which advises the government and informs public policy, recommends that regular screening begin age 50.
Even if the cancer society dismisses the study’s finding that women from 40 to 49 were more likely to have a false-positive mammogram compared with women in their 50s, why doesn’t it find the task force conclusions compelling?
Call us cynical, but could it be because it’s in the interests of the cancer society to encourage the use of medical services?
In fact, the new study is not that new; other studies have supported similar findings, and there simply is no medical benefit to a screening test that results in false positive.
As the AP pointed out, the U.S. spends much more on health care than any other country, but still lags other developed nations in life expectancy and other health indicators. So it’s worthwhile to compare the effectiveness of competing treatments, tests and medications.
Spending more on cancer treatment might make sense; another study in Health Affairs found that cancer death rates were lower in countries that spent more on cancer care, and that countries that increased spending the most made more progress in reducing death rates.
But spending more to look for cancer? That’s a different story.