Indications and risk-benefit of mammography.

Mammography has recently undergone a striking improvement in image detail along with a corresponding decrease in radiation exposure. Although the data of the Breast Cancer Detection Demonstration Project is tainted by an absence of a control group of women, the high rate of detection of early cancer by mammography alone in the participants above or below age 50 years implies that mammography is useful in detecting breast cancer before the appearance of a palpable mass. Early diagnosis results in higher survival rates. Mammographers should continuously seek the least radiation exposure consistent with a sharp image. Given present knowledge of its benefit and potential risk, mammography should be performed when a significant suspicion of breast cancer exists at any age, but it should not be performed under age 35 years without such suspicion. A baseline mammogram should be performed in the 35 to 40-year age group. The periodicity of survey mammography in asymptomatic women under 50 years should be determined by analysis of relative risk factors for breast cancer. For asymptomatic women age 50 years and older, periodic screening mammography is sound medical practice.