Fewer Late-Stage Cancers Found With Annual Vs Biennial Mammography

By Megan Brooks

December 03, 2019

NEW YORK (Reuters Health) - Cancers detected in women who undergo annual mammography screening are smaller and less advanced than those found with biennial screening, according to a retrospective study.

"Annual screening, in comparison to biennial screening, resulted in a significant reduction of late-stage disease among women age 40-84 years. Additionally there were fewer interval cancers and smaller tumor size," Dr. Sarah Moorman of Michigan Medicine in Ann Arbor told Reuters Health by email.

Dr. Moorman will present her study December 4 in Chicago during the annual meeting of the Radiological Society of North America.

Currently, the National Comprehensive Cancer Network (NCCN) recommends annual mammography screening beginning at age 40 for women at average risk for breast cancer, while the U.S. Preventive Services Task Force says screening every two years beginning at age 50 is sufficient for most women.

Dr. Moorman and colleagues reviewed the records of 232 women, ages 40 to 84, who were diagnosed with breast cancer at a mean age of 62. Almost three-quarters of the cancers were invasive.

Two hundred women (86%) underwent mammography screening annually (every nine to 12 months), while 32 (14%) had biennial screening (every 21 to 27 months). There were no marked differences in baseline characteristics between the annual and biennial groups, including age, menopausal status, hormone replacement use, high risk status, family history and race.

Biennial screening was associated with significantly more late-stage tumors than annual screening (44% vs. 24%, P=0.02), as well as more interval cancers (38% vs. 11%; P<0.001), and larger average tumor size at detection (1.8 cm vs. 1.4 cm; P=0.04).

Women who had biennial screening also tended to get more-aggressive treatment than women who had annual screening, including axillary lymph node dissection (19% vs. 12%) and chemotherapy (38% vs. 28%).

Dr. Moorman told Reuters Health that the variations in screening recommendations in the United States are "confusing for both patients and providers. Our study supports more frequent annual screening and we believe annual screening should be endorsed."

SOURCE: http://bit.ly/2OpN4UN

Radiological Society of North America 2019.