High levels of visceral fat were associated with a significantly increased risk of death in women with clear cell renal cell carcinoma (RCC), but not in men, results of a recent retrospective study show.
Conversely, the combination of low visceral fat and low glucose metabolism pinpointed a subset of women with clear cell RCC who had excellent prognosis, according results of the study, which were published online ahead of print in Radiology (March 20, 2018).
Those findings suggest visceral fat and tumor glucose metabolism might be combined in a risk stratification system that could be interpreted differently, based on the sex of the patient, said investigator Joseph E. Ippolito, MD, PhD, of Mallinckrodt Institute of Radiology, Washington University in St. Louis School of Medicine.
“There has been some evidence here and there about the role of visceral fat in the kidney, but I think we're basically one of the first, if not the first, to show that there could actually be sex differences in how this plays out prognostically,” Dr. Ippolito said in an interview with Urology Times.
Previous studies have shown that increased visceral fat correlates with poor outcomes in patients with colorectal and pancreatic cancers, while results of RCC studies have been mixed, Dr. Ippolito said. Moreover, these analyses generally have not looked at sex-specific differences in outcomes.
To determine whether sex differences in visceral fat composition predicted survival in this cohort, the investigators measured visceral fat in computed tomography (CT) images from 222 patients with clear cell RCC. Images were obtained from The Cancer Imaging Archive, the public resource that provide clinical images matched to subjects in The Cancer Genome Atlas (TCGA) and other genomics archives.
To control for concomitantly high subcutaneous fat in obese patients, they specifically looked at relative visceral fat area (rVFA), or visceral fat as a percentage of total fat area.