Breast cancer kills more women worldwide than any other cancer. While the global medical community is unified in efforts to reduce the frequency and number of these deaths, there remains a fierce ideological divide on how and when to utilize breast cancer screening strategies to accomplish this goal.

“The definition of what constitutes the best implementation of mammographic screening programs (e.g., which age groups should be screened and with what frequency) needs to be revisited in light of the results of recent studies,” wrote Béatrice Lauby‑Secretan, PhD, and her co-authors from the World Health Organization’s International Agency for Research on Cancer (IARC) in a special report published online June 3 in the New England Journal of Medicine.

The report details results of the IARC researchers’ extensive review of findings from recent studies regarding breast cancer screening implementation, which concluded that the risk of death resulting from breast cancer is reduced by 40 percent in women aged 50-69 who receive regular mammography screening exams.

The study results analyzed by the authors were less conclusive regarding the screening frequency of younger women, which has been a point of contention between early screening advocates and those concerned with overdiagnosis and unnecessary radiation exposure. “Fewer studies assessed the effectiveness of screening in women 40 to 44 or 45 to 49 years of age who were invited to attend or who attended mammographic screening, and the reduction in risk in these studies was generally less pronounced,” wrote Lauby-Secretan, et al.

The authors’ findings are part of an update of the IARC’s Handbook on breast cancer screening, which was last updated in 2002. Myriad changes in screening technology, research, implementation strategies and patient outcomes have taken place since that time, prompting the IARC to undertake the literature review and perpetuate the process of providing timely and effective guidance to women around the world.

“Screening for breast cancer aims to reduce mortality from this cancer, as well as the morbidity associated with advanced stages of the disease, through early detection in asymptomatic women,” the authors wrote. “The key to achieving the greatest potential effects from this screening is providing early access to effective diagnostic and treatment services. Comprehensive quality assurance is essential to maintaining an appropriate balance between benefits and harms.”