Body mass index may serve as a key clue to catching interval cancers within two years of a negative mammogram, experts detailed recently.
The modality has helped reduce mortality rates by upward of 20%, but women are still left vulnerable to the disease between regular annual or biennial screenings. Some 15% of breast cancers occur between a negative mammogram and the next regular visit, University of Pennsylvania researchers noted.
Anne Marie McCarthy, PhD, and colleagues conducted a large-scale analysis incorporating tens of thousands of women, looking for any interval cancer risk factors. They found that obese women had a 90% increased risk of advanced cancer in year 1 after a negative mammogram, according to a study published in the latest issue of Cancer.
“Our results suggest that in addition to breast density, BMI may be an important risk factor to consider when one is assessing breast cancer risk, particularly in the short term,” McCarthy, an assistant professor of epidemiology at the Perelman School of Medicine, and colleagues concluded. “Given that women with a higher BMI have an increased risk of an advanced breast cancer diagnosis, they might consider annual mammography or supplemental screening with breast MRI, which may better detect small and aggressive tumors.”
For the study, scientists analyzed nearly 294,000 negative mammograms across 75,000 women, performed between 2006-2015 at Massachusetts General Hospital. McCarthy et al. focused on two-year intervals among women over age 50—based on the U.S. Preventive Services Task Force guidelines—noting a lack of research using this timeline.
Altogether, the analysis found 1,345 breast cancer cases, with 26.5% (357) at an advanced stage and the other 73.5% (988) of the early variety. Along with BMI, breast density, a prior biopsy and family history were associated with an increased risk of both early and advanced cancers. Meanwhile, overweight and obese women had a 40% higher risk of developing early or advanced cancer in the second year following a negative mammogram.
McCarthy and co-authors were unable to explore racial differences in diagnosis, due to the small number of non-white women in the sample.
“Future multicenter studies should examine the relationship of BMI with advanced cancer diagnosis and take the time since the last screen into account,” they advised. “Additionally, studies assessing the predictive ability of additional imaging biomarkers and genetic factors for the short-term risk of advanced cancers are warranted.”
You can read the full analysis in the journal of the American Cancer Society here, and a summary from the University of Pennsylvania here.
Marty Stempniak has covered healthcare since 2012, with his byline appearing in the American Hospital Association's member magazine, Modern Healthcare and McKnight's. Prior to that, he wrote about village government and local business for his hometown newspaper in Oak Park, Illinois. He won a Peter Lisagor and Gold EXCEL awards in 2017 for his coverage of the opioid epidemic.