A woman's decision to undergo a screening mammogram is an important first step to help ensure early detection of breast cancer. Just as vital, however, is her choice of a high-quality facility and mammographer.
"The mammographic exam is a very difficult examination to perform and interpret properly," said Dr. R. James Brenner, chief of the section of breast imaging at Cedars-Sinai Medical Center. "The results are very much dependent on the person or persons performing and interpreting the mammograms."
A mammographer's inexperience, said Brenner, could result in overlooking cancers on mammograms or in what he terms "overcalling"--determining that an area of the breast is "suspicious for malignancy when it has no known radiologic features of malignancy." Such overcalling can result in unnecessary biopsies, not to mention untold patient anxiety.
In recent years, as organizations such as the American Cancer Society have publicized the need for screening mammography, the number of facilities offering it has increased greatly. "A lot of centers are entrepreneurial," said one expert, "(although) there are some out there that are very good."
To improve the odds of finding the best possible facility and mammographer, experts suggest asking some or all of the following questions before making an appointment at a hospital, specialized breast center, radiologic clinic or other facility.
- What type of mammogram is done?
Two methods are acceptable today, experts agreed. One method is film-screen mammography using equipment specially designed for mammograms; the other is xeromammography which electronically records the X-ray image on special paper.
"If the equipment looks like the kind used for a chest X-ray or a GI series, or if the breast is not compressed (during the examination), go away," advised Dr. Myron Moskowitz, professor and director of breast imaging at the University of Cincinnati Medical Center and a member of the American College of Radiology's Committee on Breast Imaging.
- What does the screening examination include?
Ideally, a screening mammogram should also include a physical examination of the breasts. "Mammography is not sufficient, even when done properly," said Dr. Philip Strax, a New York City radiologist and a pioneer in mass breast cancer screenings. "You've got to have a physical examination by well-trained fingers." The exam should be performed, Strax said, by a doctor or by a health-care professional trained and supervised by a doctor. Examination by mammography alone is about 90% accurate, but the addition of the physical examination (plus a monthly breast self-exam) increases the likelihood of cancer detection.
If the addition of a physical examination makes the cost of mammography prohibitive, the physical exam can be obtained later from a woman's family physician or gynecologist, said Dr. Lawrence W. Bassett, chief of the mammography section at the UCLA School of Medicine.
- Who will interpret the mammogram?
If the mammogram is not interpreted by a radiologist, find another facility, experts advised. If a radiologist does interpret the mammogram, ask if he has had any special training in mammography. Asking the radiologist his accuracy rate is another good idea, said Brenner. An accuracy rate of 85%, he believes, is "acceptable." Allowing that 85% does not sound very good, Brenner explained that the rate "can approach 100% " with the addition of the physical examination.
- How much will the exam cost?
In the Los Angeles area, screening mammograms cost from $45 to $200, according to Bassett, who conducted a telephone survey of about 50 mammography facilities earlier this year. "The average cost was $125."
At some facilities, the costs may be driven up when personnel suggest tests in addition to mammography, now considered the most useful technique for screening and detecting breast cancer in its early stages. Women who undergo screening mammograms should be wary, experts said, if other screening methods are advised without apparent reason.
One such method, transillumination or diaphanography (use of light to illuminate the breast's interior) has "currently no diagnostic value in and of itself" to evaluate breast cancer, according to Brenner, although it "may be useful as an ancillary procedure."
Another method, thermography (detection of the heat pattern given off by the skin) is currently under study to determine if it can be used to predict who will get breast cancer, Brenner said. "As a diagnostic test, it has been proven to be unsatisfactory for evaluating breast cancer."
Ultrasound (use of sound waves to detect abnormalities) is useful only as an adjunct to mammography, experts agreed.
Magnetic resonance imaging or MRI (use of radio waves to produce three-dimensional body images) "is a costly, experimental procedure that needs more investigation (for use in breast cancer detection)," said Dr. Richard H. Gold, a professor of radiological sciences at the UCLA School of Medicine.