What Doctors Don't Tell YouMammograms are at their poorest in detecting breast cancer when the woman is under 50 and when the time between screenings is about two years.
Equally worrying, the test is also poor at detecting cancers in women who have a family history of breast cancer, possibly because of rapid tumour growth.
Researchers from the University of California confirmed the doubts that several international health boards have about the benefits of screening among the under 50s.
The research team believe that mammograms are better at detecting cancerous growths in the over 50s because their breasts are more fatty.
But their other findings, made after studying the records of 28,271 women aged over 30, give greater cause for concern. Paradoxically, those at highest risk because of their family history seem to be helped least by mammography.
!AJAMA, 1996; 276: 33-8.
Maryon Stewart
Daniel Redwood DC
Tom Ferguson MD