I’ve been saying this for years. There was even an exodus of readers who were so angry that I was implying their treatment might have been unnecessary — but it could have been. And now, another study, a big one, saying the same thing:
The importance of regular mammograms to ending breast cancer has been widely endorsed by everyone from a government-backed panel to patient advocacy groups and Angelina Jolie. Is it possible they’ve all been wrong?
A new study in JAMA Internal Medicine published Monday looked at data from 16 million women in 547 U.S. counties in 2000. More than 53,000 were diagnosed with breast cancer that year. As expected, the researchers found that the number of breast cancer diagnoses rose with more aggressive screenings. The surprise: the number of deaths remained the same.
The study found that mammography resulted in diagnosis of additional small cancers, but was not associated with higher detection of more advanced and dangerous larger tumors. The researchers — including Richard Wilson, a professor at Harvard University who has been conducting a series of studies on risk-benefit analysis and cancer — argued that these findings “suggest widespread overdiagnosis.”
The issue of overdiagnosis (and overtreatment) in cancer care — not just in breast cancer but also in cancers of other regions of the body such as the prostate and lungs — has prompted heated debate in recent years. One big issue in breast cancer specifically is the number of false positives in mammograms, which are estimated to be anywhere from less than 10 to 50 percent of all women who are screened. In an opinion piece accompanying the Wilson study, researchers from the University of Washington School of Medicine expressed concern that that this lack of clarity has left both patients and their caregivers in a conundrum.
“Treatment of an overdiagnosed tumor cannot provide benefit, but it can lead to harm. Overdiagnosis and overtreatment are now widely acknowledged to be an important harm of medical practice, including cancer screening,” Joann G. Elmore and Ruth Etzioni wrote.
Just last month, researchers from the University of Copenhagen warned of the psychological strain of false-positive mammograms in a study in the journal Annals of Family Medicine. They found that even when women are told that the initial diagnosis was wrong, they still show signs of stress and depression several years later.