One study looked at a community screening program for women aged 50-69, and showed that women who were screened regularly had a better prognosis than women who did not participate in screenings. A second study shows that in the long run, up to 20 years after diagnosis, early detection is the most important factor in how a woman will fare against breast cancer.
There has been some largely academic controversy between scientists and researchers about whether mammograms and self-exams by women prevent breast cancer deaths in the long run. These arguments may have confused some women as to whether or not a mammogram is still recommended.
The fact is that mammograms are a relatively low-cost and easy-to-administer method of detecting breast cancer. Even though they may miss some cancers or result in some unnecessary biopsies to rule out cancer in some cases, a regular mammogram is still the most important tool in detecting breast cancer in the general population.
The American Cancer Society recommends a clinical breast exam by a doctor every three years for women aged 20-39, and a clinical breast exam and a mammogram every year for women aged 40 and older.
A woman should continue with this screening schedule throughout her old age, too, since the risk of cancer goes up with age.
A breast self-exam on a regular basis can help you notice changes in your body, and you should tell your doctor right away if there are changes. But you need to learn how to do a self-exam properly, and realize that it does not replace a regular visit to the doctor for screening. A mammogram can detect a suspicious mass much earlier than a self-exam. Current recommendations say women need to know both the benefits and the limitations of breast self-exams, and told that it's OK for women to choose to perform them occasionally or not to perform them at all.
For women at high risk from factors including genetic predisposition, family history or a personal history of disease, the guidelines suggest evaluation for screening much earlier in life. They also suggest using other screening techniques like ultrasound and magnetic resonance imaging, or MRI, in addition to a mammogram. Women at high risk should talk to their doctors about timetables for screening.