April 3, 2000 (Chantilly, Va.) -- Medical experts say there are several reasons why a mammogram may fail to detect a cancerous tumor:
The technology. Mammograms involve squeezing a woman's breast between two plates of glass -- a technique that is awkward at best. Old or badly maintained equipment and poorly trained technicians can increase the odds of an inaccurate film.
The quality of a woman's breast. Mammograms aren't good at detecting cancers in breast tissue that is dense or fibrous, as is common among female athletes and premenopausal women.
The pace of medicine. With radiologists under pressure to read more films more quickly, the risk of making mistakes has grown.
Studies on mammogram accuracy show that screenings miss anywhere from 5% to 17% of abnormalities. Yet many patients continue to believe that a "clear" mammogram is the same as a clean bill of health.
Breast cancer is a complex disease that’s different for every woman. Before you start a treatment, your doctor will want to know the size of the tumor and how far it has spread in your body, called the stage of the cancer. There are five basic stages, 0 through IV, and a number of sub-stages.
Staging is a way for doctors to describe your condition. It doesn't tell the whole story, though. Your doctor will think about many things before she recommends treatments for you, including:
"Even though there is no perfect test, and no perfect doctor, and no perfect reading, patients expect perfect results,'' says Phan Huynh, M.D., a breast imaging specialist at the University of Texas Health Science Center in Houston.
Michael D. Towle writes regularly for WebMD on health and legal issues.