Having a yearly mammogram greatly reduces the risk of mastectomy following breast cancer in women between the ages of 40 and 50 years, according to a study presented Dec. 1 at the annual meeting of the Radiological Society of North America (RSNA) in Chicago.
“The results of this study support the importance of regular screening in the 40 to 50 age group,” said lead author Nicholas M. Perry, MBBS, director of the London Breast Institute at the Princess Grace Hospital in London. “Women in this age group who had undergone mammography the previous year had a mastectomy rate of less than half that of the others."
These findings are particularly relevant in the U.S., where the U.S. Preventive Services Task Force (USPSTF) issued controversial screening mammography recommendations in November 2009, which included shifting the annual screening routine to a biannual exam for women between the ages of 50 to 74 and eliminating screening entirely for women younger than age 50 and older than age 74. These recommendations have resulted in a year’s worth of backlash.
An estimated 207,090 new cases of invasive breast cancer will be diagnosed in the U.S. in 2010. Currently, the American Cancer Society (ACS) recommends annual mammography screening for women beginning at age 40 in the U.S., in spite of the USPSTF recommendations. There are no routine screening guidelines for women under 50 in the U.K.
Perry and colleagues studied the benefits of screening women between the ages of 40 and 50, the frequency of mammography and the type of treatment after breast cancer diagnosis.
The researchers reviewed the clinical data available on women from 40 to 50 years of age who had been diagnosed with breast cancer and treated at the London Breast Institute. Between 2003 and 2009, 971 women had been diagnosed with breast cancer.
At the time of diagnosis, 40 percent of the women were under 50, with 156 of these women completing treatment at the center. Of the treated women, 73 percent had no prior mammograms. Forty-two women had been previously screened with mammography, of whom 29 had at least one mammogram within the previous two years. Of those, 16 women had a mammogram one year prior.
"We reviewed the records of the women needing mastectomy to determine whether or not they had undergone mammography the previous year," Perry said. "We were surprised at the degree of benefit obtained from yearly screening in this age group."
In women aged 40 to 50 with breast cancer diagnosed at the U.K. center, Perry and colleagues found that only 10 percent had undergone prior mammography in accordance with ACS guidelines.
Data showed that mastectomy was the required treatment for 19 percent of the 16 women who had been screened the prior year, compared to 46 percent of the 140 women who had not been screened in the past year.
"Regular screening is already proven to lower the chance of women dying from breast cancer," Perry said. "The results of our study support the importance of regular screening in the under-50 age group and confirm that annual mammography improves the chances of breast conservation should breast cancer develop."