Women who skip even a single scheduled mammography screening exam before they’re diagnosed with breast cancer face a much higher risk of dying from the disease, according to a large prospective study published Tuesday.
The analysis of more than half a million women found regular mammograms significantly reduce a woman’s risk of dying from breast cancer. And while Swedish researchers guessed that routine preventative imaging would likely impact mortality rates, the extent of their findings proved unexpected.
“While we suspected that regular participation would confer a reduction greater than that with irregular participation, I think it is fair to say that we were slightly surprised by the size of the effect,” lead author Stephen W. Duffy, MSc, a cancer screening professor at Queen Mary University of London, explained in a statement.
The findings confirm the hypothesis that routine visits limit the opportunity for cancer to grow before it’s detected, the authors added March 2 in Radiology.
To better understand attendance patterns and associated cancer risk, a multinational group of oncology experts analyzed data from nearly 550,000 mammography-eligible women. Funded by the American Cancer Society, the team included mammography screenings from nine Swedish counties performed between 1992 and 2016.
Women were divided into cohorts based on whether they attended their two most recent scheduled screening exams prior to receiving a cancer diagnosis (serial participants) or if they did not (nonparticipants).
Overall, completing the two breast exams protected patients from death compared to participating in only one or neither, the researchers reported.
In fact, serial patients saw a 50% lower incidence of breast cancer-related fatality within 10 years of their diagnosis compared to serial nonparticipants. And women who underwent both exams experienced a 29% drop in mortality compared to those who only completed one of their two appointments.
Going forward, the group plans to study the effect of interval cancers that form between mammography screenings.
“We are planning further prognostic research into the mechanism of this effect,” Duffy added. “For example, we plan to investigate whether and—if so—to what extent regular attendance improves the prognosis of interval cancers as well as screen-detected cancers. Estimation of this by time since last screen may have implications for policy on screening frequency.”
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.