Breast Cancer Diagnosed Between Mammograms Isn't More Aggressive

Are breast cancers diagnosed in women who have had previously normal screening mammograms more aggressive than breast cancers diagnosed in women who haven't undergone screening mammograms? To find out, Norwegian investigators carried out a population-based observational study.

In Norway, older women (age, 50–72) now are invited to receive screening mammography every 2 years. Study participants were 1800 women with “interval breast cancer” (diagnosed within 26 months of their last normal screening mammograms and before their next scheduled mammograms) and 5300 women with breast cancer who had not undergone screening mammography. Compared with the nonscreened group, women in the interval-cancer group exhibited slightly higher percentages of lo…