A recent Canadian study looked at breast cancer incidence and mortality up to 25 years in 89,835 women ages 40 to 59 who did or did not undergo mammography screening.

The women were randomly assigned to a treatment group receiving five annual screens or a control group who received no screening. The main outcome studied breast cancer death.

In the 25-year follow-up period, 3,250 women in the mammography part of the study and 3,133 women in the control part were diagnosed with breast cancer; 500 and 505, respectively, died of breast cancer.

There was no difference in the findings between women ages 40 to 49 versus women ages 50 to 59.

Writing in the January 7, 2014 issue of Ca: A Cancer Journal for Clinicians, the authors concluded, “Annual mammography in women aged 40 to 59 does not reduce mortality from breast cancer . . . ”

There is no doubt that mammography can detect a breast lesion that is too small to be palpated.

However, it has never been shown to lower mortality from breast cancer. In fact, if you look at the age-adjusted mortality rate from breast cancer from 1930 to the present time, we have made little if any progress on reducing mortality from breast cancer.

What little progress we have made may be due to diagnosing nonaggressive breast cancers — particularly DCIS breast cancer.

However, early diagnosis of nonaggressive breast cancer may result in overtreatment and adverse effects from treating lesions that would normally not metastasize.

In fact, in this study the authors reported that 22 percent of screen-detected invasive breast cancers were overdiagnosed.

We have a big mess with breast cancer. We spend too much money on mammograms that are not saving lives. We spend too little money on figuring out why one in seven U.S. women is suffering from breast cancer.