Mammography results in substantial overdiagnosis of
breast cancer, concludes study
from: Jacqui Wise bmj 2012;345:e7910 doi: 10.1136/bmj.e7910
A new study in the New England Journal of Medicine (Bleyer A, Gilbert Welch H. Effect of three decades of screening mammography on breast-cancer incidence. N Engl J Med 2012, doi:10.1056/NEJMoa1206809) estimates that more than 70 000 women in the US were overdiagnosed in 2008 (which is almost a third of breast cancers diagnosed in women aged 40 or over). Numbers of overdiagnosed women over the past 30 years are estimated 1.3 million.
The authors, Archie Bleyer of St Charles Health System, Oregon, and H Gilbert Welch of the Dartmouth Institute for Health Policy and Clinical Practice, Hanover, New Hampshire, concluded “Our study raises serious questions about the value of screening mammography.’…“Although no one can say with any certainty which women have cancers that are overdiagnosed, there is certainty about what happens to them: they undergo surgery, radiation therapy, hormonal therapy for 5 years or more, chemotherapy, or (usually) a combination of these treatments for abnormalities that otherwise would not have caused illness.”