Results of a new study show that breast sonography is more accurate than mammography in symptomatic women 45 years old or younger, and may be an appropriate initial imaging test in investigating these women, says Nehmat Houssami, MD, PhD, and lead author of the study.
The study, published in the April 2003 issue of the American Journal of Roentgenology, "is the first published study to examine the comparative sensitivity and specificity of mammography and sonography in relation to age in young women with breast symptoms, where the two tests were interpreted independently of each other and where almost all subjects had undergone both tests," says Dr. Houssami.
To conduct the study, Dr. Houssami and other researchers at the School of Public Health at the University of Sydney, the MBF Sydney-Square Breast Clinic, and Northern Sydney and Central Coast BreastScreen in Australia, used sonography and mammography to examine 480 women between the ages of 25 and 55.
Results of the study indicate that sonography correctly identified 84.9 percent of breast cancers in symptomatic women 45 years old and younger, whereas mammography correctly identified 71.7 percent of breast cancers in this group. Results also show that both mammography and sonography accurately identify 79.1 percent of breast cancers in women 46-55 years old.
Based on their findings, Dr. Houssami, suggests, "If a woman has breast symptoms (or changes) or is found to have a lump (or swelling) on examination, then we recommend that women 45 years and younger should be investigated with sonography as the main imaging test, and those older than 45 years should be investigated with mammography as the main imaging test."
This idea is contrary to current recommendations or standards, which suggest age 35 as the age to decide which test to use as the primary imaging in women with symptoms of breast cancer, says Dr. Houssami.
However, Dr. Houssami warns, "Research evidence is intended to guide, and not to replace, clinical decision-making which takes into consideration the individual woman's situation, such as her risk of having breast cancer and her preferences, as well as the specific clinical findings."
Dr. Houssami cautions, "This study is not about screening–it is about diagnosis of women who are referred for testing because they are experiencing breast symptoms. There is a critical difference, our study has nothing to do with screening; mammography is the only proven screening test for breast cancer."