There are far too many screening mammograms that had done far too little in preventing death in breast cancer patients, a recent study suggests.
Researchers analyzed the medial records of breast cancer patients in 547 counties across the U.S. and found that mammograms are often used unnecessarily. Moreover, too many screenings led to the discovery of very small tumors that were otherwise harmless if women weren’t subjected to invasive breast cancer treatments, the study also finds.
“The clearest result of mammography screening is the diagnosis of additional small cancers. These findings suggest widespread over-diagnosis,”
study authors wrote in a paper on the issue that was published June 7 in the JAMA Internal Medicine.
Scientists gathered data on women who had performed at least one screening mammogram from a national registry called the Surveillance, Epidemiology, and End Results, which is managed by the National Cancer Institute.
Out of 16 million women, about 53,000 were diagnosed with breast cancer in a single year, and they were monitored for over a decade. Ten years later, about 15 percent died of the disease, while 20 percent died of other health issues.
The screening rate for breast cancer varied from 39 percent to 78 percent, researchers found. But the counties that had higher screening rates surprisingly didn’t have lower mortality rates as they should have.
Scientists found that “the extent of screening” had no effect on the 10-year mortality rate.
On the other hand, for every 10 percent on the screening rate scale, incidence of breast cancer jumped 16 percent. So, the over-diagnosis epidemic was associated with an additional 36 to 50 new cases per 100,000 women.
We’re talking about over-diagnosis because many tumors were less than 0.8 inches (2 cm), while big tumors didn’t benefit from more screening mammograms as mortality rates showed. In other words, extra screening didn’t help doctors detect tumors before they grew large enough to pose a life-threatening risk.
Also, extra screening led to diagnosis of early-stage cancers but had no influence on advanced-stage tumors, researchers noted. Authors explained that the cause of these anomalies is “widespread over-diagnosis” which is accountable for finding smaller tumors but does not change the death rate among breast cancer patients. researchers noted that mortality rate doesn’t budge even where the number of diagnosed cancers nearly doubles.
This latest study may make many doctors shake head in disbelief since there’s an entire culture of getting as many mammograms as one could to stay away from breast cancer. A culture that had been promoted by awareness campaigns, as well.
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