Women in their 40s with no family history of breast cancer are just as likely to develop invasive breast cancer as are women with a family history of the disease, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). These findings indicate that women in this age group would benefit from annual screening mammography.

"We believe this study demonstrates the importance of mammography screening for women in this age group, which is in opposition to the recommendations issued by the task force," said Stamatia V. Destounis, M.D., radiologist and managing partner of Elizabeth Wende Breast Care, LLC, in Rochester, N.Y.

For the study, Dr. Destounis and colleagues performed a retrospective review to identify the number and type of cancers diagnosed among women between the ages of 40 and 49-with and without a family history of breast cancer-who underwent screening mammography at Elizabeth Wende Breast Care from 2000 to 2010. The researchers then compared the number of cancers, incidence of invasive disease and lymph node metastases between the two groups.

Of the 1,071 patients in the 40 to 49 age group with breast cancer, 373 were diagnosed as a result of screening. Of that 373, 39 percent had a family history of breast cancer, and 61 percent had no family history of breast cancer. In the family history group, 63.2 percent of the patients had invasive disease, and 36.8 percent had noninvasive disease. In the no family history group, 64 percent of the patients had invasive disease, and 36 percent had noninvasive disease. The respective lymph node metastatic rates were 31 percent and 29 percent.

"In the 40 to 49 age group, we found a significant rate of breast cancer and similar rates of invasive disease in women with and without family history," Dr. Destounis said. "Additionally, we found the lymph node metastatic rate was similar."

According to Dr. Destounis, these results underscore the importance of early detection and annual screening mammography for women between the ages of 40 and 49 whether or not they have a family history of breast cancer.

Coauthors are Jenny Song, M.D., Posy Seifert, D.O., Philip Murphy, M.D., Patricia Somerville, M.D., Wende Logan-Young, M.D., Andrea Arieno, B.S., and Renee Morgan, R.T.