Should Women in Their 40s Have Annual Mammograms?

Women in the early and mid-50s still have menstrual periods. If a woman is not yet through menopause and she gets breast cancer, it's going to grow faster. The sweet spot for starting mammography for average risk women is age 40 because that's when the incidence ticks up. But we don't do mammograms routinely until age 40 because breast cancer is not rare enough to justify doing mammogram on whole population.