According to an article from UCLA, breast cancers that go untreated are more likely to spread to other parts of the body, so regular screenings are very important.
The goal of a mammography screening is to find breast cancers before they are large enough to be identified and detected in a clinical exam.
In the article, Lawrence Bassett, M.D. from the Iris Cantor Center for Breast Imaging says that between the ages of 40 and 50, about 15 percent of breast cancers occur.
Women who are at an increased risk of developing breast cancer should begin getting screenings sooner than age 40. Those who have a strong family history of breast cancer or know that they carry mutations on their BRCA-1 or BRCA-2 genes may be recommended to get screened every six months.