Body composition has been proposed as a prognostic factor in renal cell carcinoma (RCC), but evidence remains inconsistent, particularly in elderly patients. This study aimed to evaluate whether computed tomography (CT)-derived body composition indices are associated with overall survival (OS) in patients aged ≥ 75 years with RCC. This retrospective cohort study included all RCC patients aged ≥ 75 years diagnosed at Tampere University Hospital between 2003 and 2017 with available abdominal CT imaging.The study cohort comprised 239 patients. The formation of the dataset is illustrated in Figure 1. Body composition parameters, including psoas muscle index (PMI), skeletal muscle index (SMI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and waist circumference, were measured at the third lumbar vertebra level. The primary outcome was OS, and the secondary outcome was risk of surgical complications. Cox proportional hazards models were used for survival analyses, with adjustment for established prognostic factors. Subgroup analyses were performed, and associations with surgical outcomes were assessed using correlation and logistic regression analyses. A total of 239 patients aged ≥ 75 years with RCC were included. Median age at diagnosis was 80 years (75–94), and 67% underwent surgical treatment. Median follow-up was 4 (0-21) years. Sarcopenia was common across the cohort as low muscle mass was found in 95–100% of women and 94–98% of men. In univariable analysis, waist circumference showed a weak inverse association with OS (HR 0.99, 95% confidence interval (CI): 0.98–1.00). In subgroup analysis higher VATI was associated with improved survival among non-operated subgroup (HR 0.43, 95% CI 0.19–0.93). However, these findings were inconsistent and of small magnitude. No significant associations were observed in sex-stratified analyses. For surgical outcomes, weak correlations were found between waist circumference and VATI with intraoperative blood loss (r = 0.24, p = 0.024), SATI with length of hospital stay (r = 0.22, p = 0.013), and VATI with intraoperative organ injury (OR 1.01, 95% CI 1.00–1.02). After correction for multiple testing, only the association between VATI and blood loss remained significant. Overall, effect sizes were small. CT-derived body composition indices do not appear to have clinically meaningful utility in predicting OS or surgical complications in elderly RCC patients. These findings suggest that body composition measurements derived from routine CT imaging should not be used in isolation for risk stratification in this population. Instead, treatment decisions for elderly RCC patients should be based on a comprehensive geriatric assessment.
Pajunen et al. (Fri,) studied this question.