Study suggests breast cancer overdiagnosed

As a result of mammographic screening programs, as many 1.3 million women over age 40 were overdiagnosed with breast cancer over three decades, researchers reported in a new study in the New England Journal of Medicine.

The research received extensive print and online coverage. Many articles focused on the controversy the study has caused, with several physicians harshly criticizing the study, with one even calling it “junk science.” I think he’s probably wrong, however.

The Los Angeles Times reported that approximately “a third of all tumors discovered in routine mammography screenings are unlikely to result in illness, according to a new study that says 30 years of the breast cancer exams have resulted in the overdiagnosis of 1.3 million American women.”

The study, “published in the New England Journal of Medicine, argues that the increase in breast cancer survival rates over the last few decades is due mostly to improved therapies and not screenings, which are intended to flag tumors when they are small and most susceptible to treatment.”

The Wall Street Journal reported that for the study, researchers analyzed data from the Centers for Disease Control and Prevention’s National Health Interview Survey, as well as from the Surveillance, Epidemiology and End Results Program.

The AP reported, “‘This study is important because what it really highlights is that the biology of the cancer is what we need to understand’ in order to know which ones to treat and how, said Dr. Julia A. Smith, director of breast cancer screening at NYU Langone Medical Center in New York.” Physicians “already are debating whether DCIS, a type of early tumor confined to a milk duct, should even be called cancer, she said.”

However, “another expert, Dr. Linda Vahdat, director of the breast cancer research program at Weill Cornell Medical College in New York, said the study’s leaders made many assumptions to reach a conclusion about overdiagnosis that ‘may or may not be correct.'”

The Washington Post reported, “Debra L. Monticciolo, a physician who chairs the American College of Radiology’s Quality and Safety Commission, questioned many of the study’s methods, including the data used to account for fluctuations in the underlying incidence of breast cancer due to factors like the use of hormones.”

Monticciolo is quoted as saying, “It stuns me that this got through peer review.” Monticciolo “added that as a physician, she found it hard to believe that such a large share of screenings produce false positives. If that were the case, there would be countless tales of miraculous recoveries by women who refuse traditional treatment after being diagnosed with early-stage breast cancer.” Reuters also pointed out criticism of the study from Dr. Monticciolo.

The Boston Globe reported, “Dr. Daniel Kopans, a senior radiologist at Massachusetts General Hospital who has been a strong advocate for mammography, questioned why the study was published in the prestigious New England Journal, calling it ‘junk science’ that could be used to ‘deny women access to screening.'” But, “others … defended the researchers’ conclusions, saying the study verifies research data that’s been published in other countries.”

USA Today reported, “Barry Kramer, director of the National Cancer Institute’s division of cancer prevention, says women should be presented with the full picture of mammography’s risks and benefits.” While “women have been instructed that ‘early detection saves lives,’ relatively few are told that screenings also have costs, including the risk of undergoing surgery, radiation and drug therapy that doesn’t help them, Kramer says.”

CNN reported, “The American College of Radiology issued a statement saying the report was ‘deeply flawed and misleading’ – a claim the study authors refute.”

NPR “Shots” blog reported, “The ACR’s main criticism is that” the researchers “don’t account for what the radiologists say was a steady increase in the incidence of invasive breast cancer. They say that can explain why mammography didn’t lower the incidence of advanced breast cancer more.”

WebMD reported, “Len Lichtenfeld, MD, deputy chief medical officer at the American Cancer Society, says the study is interesting and will lead to more discussion about mammograms.” But, according to Lichtenfeld, “It’s not a study that’s going to close the book, shall we say, on the discussion regarding the value of mammography.”

MedPage Today reported that in a statement, the American College of Radiology and the Society of Breast Imaging “argued that the assumptions in the study were wrong and that – far from there being no evidence of a screening benefit – mammograms have reduced the incidence of invasive disease.”

In a New York Times op-ed H. Gilbert Welch, one of the study’s researchers, wrote that the study found “a lot of overdiagnosis: more than a million women who were told they had early stage cancer – most of whom underwent surgery, chemotherapy or radiation – for a ‘cancer’ that was never going to make them sick. Although it’s impossible to know which women these are, that’s some pretty serious harm.” Welch wrote, “Pre-emptive mammography screening…is, at best, is a very mixed bag – it most likely causes more health problems than it solves.”

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