(HealthDay News) — Compared with annual screening, biennial mammographic screening is associated with a greater frequency of finding advanced-stage disease and interval cancers, according to a study presented at the annual meeting of the Radiological Society of North America, held from Dec. 1 to 6 in Chicago.
Sarah Moorman, M.D., from Michigan Medicine in Ann Arbor, and colleagues compared breast cancer tumor characteristics and treatment regimens among 232 women (aged 40 to 84 years) undergoing annual (9 to 15 months) versus biennial (21 to 27 months) screening mammography.
Screening frequency was annual in 86 percent of patients and biennial in 14 percent. The researchers found that baseline characteristics were similar between annual and biennial groups, including age, menopausal status, hormone replacement use, high-risk status, family history, and race. There were fewer late-stage presentations with annual screening, compared with biennial (24 versus 44 percent), and fewer interval cancers (11 versus 38 percent). There was also an association noted between biennial screening and larger mean tumor size at presentation. Greater use of axillary lymph node dissection and chemotherapy was reported for women undergoing biennial screening compared with annual screening.
“These results may be helpful in decision making regarding frequency of breast cancer screening,” the authors write.