A new study by researchers in Denmark has found that mammograms lead to “overdiagnosis” of breast cancer.
According to NBC News, researchers found that as many as one-third of women in Denmark who were diagnosed with breast cancer through mammograms had tumors that would never become cancerous, or that were slow-growing and did not require immediate treatment.
Denmark offered a unique opportunity for study, because just 20 percent of the female population age 50 to 69 was invited to participate in a screening program that spanned 17 years. Researchers examined medical records of 95,000 women who were diagnosed with breast cancer between 1980 and 2010. Some had participated in the screening program and some had not, but there was little difference between them in terms of the number of lives saved.
The authors of the study, which was published in the Annals of Internal Medicine, have thus concluded that breast cancer screening “was not associated with a reduction in the incidence of advanced cancer.”
The study joins a growing league of scientific literature that cast doubt on the value of universal breast cancer screenings, which can be both uncomfortable and anxiety-inducing. The challenge is, of course, that breast cancer is a leading killer of women, and mammograms are still the best way to detect dangerous tumors that cannot be felt.
The American Cancer Society currently recommends that women over the age of 45 get screened yearly until they are 55, and then every other year after that. “[B]y treating everybody, we clearly save some lives even if we cure some people who do not need to be cured,” Dr. Otis Brawley, medical officer at the American Cancer Society, told NBC News.
But he also pointed to the need for better genetic tests, which could tell whether a patient requires immediate treatment, or whether she can safely wait and see how her tumor progresses.
Read the full story at NBC News.