Breast Cancer Screening

Linda T. Vahdat, MD
Andrew Joe, MD

As with other cancers, the goals of breast cancer screening are twofold: to detect cancer at the earliest possible stages and consequently to improve the patient's outcome by managing the early stages of the disease. Screening includes a risk evaluation obtained from a woman's menstrual and medical history and a physical examination of the breast by a physician once or twice each year. In addition to detecting abnormal masses, the physician may also assess the density of breast tissue which may be important in interpreting mammograms.

At the present time, mammograms represent the best method for early detection of breast cancer. However, up to 30% of mammograms may be falsely negative. Breast self-examinations (BSE), performed monthly by the patient, are also useful in detecting early lesions, and can increase the chances that an abnormality will be found early.

There is general agreement that the standard of care is a baseline mammogram between the ages of 35 and 40 and yearly from age 50 upward. It's been demonstrated that annual mammograms for women over 50 reduce mortality.

However, the value of mammograms in the 40 to 50 age range is still controversial; it has usually been left up to the discretion of a woman and her physician.

Various medical organizations, including the National Cancer Institute, the American Cancer Society, the American Medical Association, and the US Preventive Services Task Force, have offered screening recommendations, but they vary in their recommendations for women between the ages of 40 and 49.

The lack of clinical efficacy and questions of cost-containment have made this issue controversial. On January 23, 1997, the National Institutes of Health Consensus Conference on Breast Cancer Screening issued a statement regarding screening recommendations for this age group. They concluded that the currently available clinical data do not warrant universal screening for women in their 40s, but that a screening mammogram may be offered to a woman before the age of 50, depending on her individual risk factors and presenting symptoms.

My opinion is that yearly mammograms are a reasonable choice for women in the 40-49 age range. Furthermore, the best time to start mammography screening should be based on the family history of breast cancer. The usual recommendation is to start mammography screening ten years before the "index case" (the age at which the youngest primary relative was diagnosed with breast cancer).

Newer imaging techniques, such as dynamic imaging studies and sonography imaging, are currently being refined. These new techniques promise increased sensitivity and specificity of screening. Such advantages will certainly further increase the value of imaging in all age groups, and will likely make the issue of imaging in younger women less controversial.