Personal vigilance

Women should not be dissuaded by a three-state study showing that even the most-skilled radiologists miss 20 percent of breast-cancer cases in diagnostic mammograms.

No fault can be found with the study led by Group Health Cooperative. But its primary lesson ought to be that the best health-care prevention is personal vigilance. Concerns over mammography raised by the study aren't new. Mammograms are an imprecise means of detecting breast cancer, but they remain the best detection tool medicine currently has. Routine mammograms indisputably reduce death rates from breast cancer among women over 50.

Mammography's imperfections underscore a need for personal empowerment in health care. Women should freely question test results — negative or positive — and especially if the results contradict medical signs or symptoms.

Shopping for a radiologist is also important.

Studies such as the Group Health one contribute to the growing body of knowledge about cancer prevention.

The more we know about the weaknesses of preventive tools, the more we can rally other resources and expand our options.