When should you start getting mammograms?By Deborah Wilburn
How frequently and at what age should women begin to get mammograms? Guidelines vary, from the American Cancer Society, which recommends annual mammograms for all women starting at 40, to the U.S. Preventive Service Task Force (USPSTF), which recommends mammograms every two years starting at age 50.
Now, a new study from the Harvard School of Public Health (HSPH) adds fuel to the debate by stating that routine mammograms may lead to significant overdiagnosis of the breast cancer, causing undue anxiety, additional costly testing, and unnecessary treatment.
The researchers analyzed data from a study of almost 40,000 Norwegian women with invasive breast cancer, 7,793 of whom were diagnosed during a 10-year rollout of the Norwegian Breast Cancer Screening starting in 1996. The remaining women were diagnosed in the 10 years prior. Researchers expected to see a decrease in late-stage breast cancer cases, thanks to mammography catching cancer at earlier stages. While the researchers didn't find a decrease in late-stage cases, they did find considerable overdiagnosis, as reported in the Annals of Internal Medicine. Of the 7,793 women who chose to be screened, 15% to 25% were overdiagnosed.
Part of the issue, say the researchers, is that radiologists have been trained to find the tiniest tumors, including those that might never blossom into breast cancer to cause symptoms or death.
The fact is, overdiagnosis is inevitable, given the difficulty in distinguishing between tumors that can escape the breast, spread throughout your body and kill you, and slow-growing tumors that never leave the breast and aren't life-threatening.
"The situation is very similar to prostate cancer screening, and even lung cancer screening, where some people are going to be treated unnecessarily, but some are going to be helped," says RealAge Chief Medical Officer Keith Roach, MD. "Because we can't tell, we doctors universally recommend aggressive treatment."
Moreover, the HSPH study "doesn't address or even question the fact that mammographic screening saves lives," says Roach. "This is the most important take-home message. I'll continue to recommend mammograms for women ages 50-74, and discuss the issue with younger and older women. I personally think that if you've have made the decision to screen, you should screen pretty aggressively."
He notes that a landmark trial found "most of the cancer deaths in the screened group were 'interval' cancers -- not there the previous screening and too late to do anything about when caught. That is, unfortunately, the peril of screening: The most aggressive cancers are likely not to be caught, while the ones you do catch are slow-growing, even the ones destined to never bother you at all -- hence, overdiagnosis."
And there's the challenge for women: Get screened and risk overdiagnosis or skip screening and risk missing a life-threatening cancer? Ultimately, it's up to you and your doctor to decide when to start screenings, based on your family history and comfort level, and how frequently to get them.
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