Quantitative Measures of Visceral Adiposity and Body Mass Index in Predicting Rectal Cancer Outcomes after Neoadjuvant Chemoradiation

Abstract

BACKGROUND The association between body mass index as a measure of obesity and rectal cancer outcomes has been inconsistent. Radiologic measures of visceral adiposity using CT scans have not been well characterized among rectal cancer patients. The objective of this study was to examine quantitative radiologic measures of visceral obesity compared with body mass index in predicting patient outcomes among patients undergoing neoadjuvant chemoradiation and resection for locally advanced rectal cancers. STUDY DESIGN We identified 99 rectal adenocarcinoma patients treated with neoadjuvant chemoradiation and surgical resection. Visceral and subcutaneous fat areas, as well as perinephric fat thickness (PNF), were recorded and categorized as obese (body mass index ≥30, visceral fat area to subcutaneous fat area ratio [V/S] ≥0.4, or median PNF). The Kaplan-Meier method, log-rank test, and Cox proportional hazards models evaluated overall and disease-free survival differences by adiposity. RESULTS Viscerally obese rectal cancer patients (V/S >0.4 or PNF) were more likely to be older, male, and have pre-existing obesity-related conditions (eg, diabetes, hypertension, and/or hyper-cholesterolemia). Elevated V/S or PNF was associated with shorter disease-free survival (p = 0.02) or overall survival time (p = 0.047), respectively. Among patients with well to moderately differentiated tumors, visceral obesity was associated with poorer disease-free survival (V/S >0.4: adjusted hazard ratio = 5.0; 95% CI, 1.2–22.0). CONCLUSIONS Visceral fat area to subcutaneous fat area ratio and PNF were strongly associated with key preoperative metabolic comorbidities, and body mass index was not. Findings suggests that elevated visceral adiposity was associated with an increased risk of recurrence, which was most evident among patients with well to moderately differentiated tumors and those with incomplete response to neoadjuvant chemoradiation treatment. Quantitative measures of visceral adiposity warrant large-scale prospective evaluation.

Association of obesity and overweight with overall survival in colorectal cancer patients: a meta-analysis of 29 studies

“…The main characteristics of the 29 included studies are summarized in Table 1. Of the included studies, 14 were conducted in North America [11,12,21,22,24,25,28,32,34,37,38,41,42,44], five were conducted in Europe [14,26,27,30,40], six were conducted in Asia [15,23,31,33,35,36], three were conducted in Oceania [13,29,43], and one study included multiple cohorts from North America and Europe [39].…”

The role of body composition evaluation by computerized tomography in determining colorectal cancer treatment outcomes: A systematic review

“…38,40 One study used three- dimensional reconstruction to calculate VFV. 25 Nine image analysis softwares were reported.…”

“…25 Two studies found no relationships with wound infection rates and visceral obesity. 33,38 Overall postoperative complications Lieffers et al found sarcopenia was associated with an increased rate of postoperative infection identified from ICD-10 diagnostic codes (23.1% vs 12.6%, p ¼ 0.036). 28 In multivariate analysis, sarcopenia independently predicted postoperative infections (OR 4.6; 95%, CI ¼ 1.5e13.9).…”

“…37 Clark et al, found that high VFA/SFA ratio rectal cancer patients were less likely to be successfully down-staged by NCR (p ¼ 0.04). 38 Impact of CTBC on CRC survival (Table 4) Moon et al demonstrated that increased visceral adiposity expressed as high VFA/SFA ratio was independently prognostic for disease-free survival (DFS) (HR 1.98, [95% CI 1.02e3.87]; p ¼ 0.044). 31 With a median follow-up of 20 months, Ballian et al found elevated BMI, and VFA/SFA ratio were associated with reduced …”

Predictive and prognostic biomarkers for neoadjuvant chemoradiotherapy in locally advanced rectal cancer

“…The measure of visceral to subcutaneous fat areas was thought to be a more accurate indicator of abdominal or visceral adiposity and quantitative measures of visceral adiposity were correlated with clininopathological variables as well as survival outcomes in a retrospective study of patients treated with chemoradiation [103]. Patients who had higher visceral fat had less T-stage downstaging while patients with no or partial response and high adiposity comprised the worst group in terms of disease-free survival.…”