Adipose tissue density on CT as a prognostic factor in patients with cancer: a systematic review

Abstract

Background: Predicting oncologic outcomes is essential for optimizing the treatment for patients with cancer. This review examines the feasibility of using Computed Tomography (CT) images of fat density as a prognostic factor in patients with cancer. Methods: A systematic literature search was performed in PubMed, Embase and Cochrane up to March 2020. All studies that mentioned using subcutaneous or visceral adipose tissue (SAT and VAT, respectively) CT characteristics as a prognostic factor for patients with cancer were included. The primary endpoints were any disease-related outcomes in patients with cancer. Results: After screening 1043 studies, ten studies reporting a total of 23ten for SAT and thirteen for VATcomparisons on survival, tumor recurrence and postsurgical infection were included. All ten studies included different types of malignancy: six localized, two metastatic disease, and two both. Five different anatomic landmarks were used to uniformly measure fat density on CT: lumbar (L)4 (n ¼ 4), L3 (n ¼ 2), L4-L5 intervertebral space (n ¼ 2), L5-S1 intervertebral space (n ¼ 1), and the abdomen (n ¼ 1). Overall, six of ten SAT comparisons (60%) and six of thirteen VAT comparisons (46%) reported a significant (p < .05) association of increased SAT or VAT density with an adverse outcome. All remaining nonsignificant comparisons, except one, deviated in the same direction of being predictive for adverse outcomes but failed to reach significance. The median hazard ratio (HR) for the nine SAT and thirteen VAT associations where HRs were given were 1.45 (95% confidence interval [CI] 1.01-1.97) and 1.90 (95% CI 1.12-2.74), respectively. The binomial sign test and Fisher's method both reported a significant association between both SAT and VAT and adverse outcomes. Conclusion: This review may support the feasibility of using SAT or VAT on CT as a prognostic tool for patients with cancer in predicting adverse outcomes such as survival and tumor recurrence. Future research should standardize radiologic protocol in prospective homogeneous series of patients on each cancer diagnosis group in order to establish accurate parameters to help physicians use CT scan defined characteristics in clinical practice.

Body composition predictors of mortality in patients undergoing surgery for long bone metastases

“…Body composition measurements included CSA and attenuation of three tissues: VAT, SAT, and paraspinal/abdominal muscle. Attenuation measurements represent the radiodensity expressed in HU of tissue and is a qualitative measurement 12 . Muscle CSA was used to determine sarcopenia using total muscle CSA (cm 2 ) divided by the height squared (m 2 ), with cutoff values of <52.4 cm 2 /m 2 for men and <38.5 cm 2 /m 2 for women based on a meta‐analysis of 7.843 patients from 38 studies 15 …”

“…These CTs are readily available for analysis and body composition measures could potentially serve as imaging biomarkers to predict outcome in this population without additional risk. Recent studies have proposed CT body composition measurements of muscle and fat depots as biomarkers for survival in patients with and without malignant disease 12–16 …”

Body Composition Parameters May Be Prognostic Factors in Upper Urinary Tract Urothelial Carcinoma Treated by Radical Nephroureterectomy

“…Studies have reported that fat parameters (VFA, SFA, SCF, IFA, SD, VD) measured at the third lumbar vertebra were associated with prognosis of patients with adenoma-derived tumors, including renal cancer, colorectal cancer, or gastric carcinoma (11,22). We found that these parameters had no effect on the prognosis of UTUC patients.…”

Prognostic Value of CT-Attenuation and 18F-Fluorodeoxyglucose Uptake of Periprostatic Adipose Tissue in Patients with Prostate Cancer

“…Currently, clinical studies have investigated the use of CT-attenuation and FDG uptake of adipose tissue to estimate the qualitative change in adipose tissue in various malignant diseases [22][23][24][25][26]40].…”

“…Currently, clinical studies have investigated the use of CT-attenuation and FDG uptake of adipose tissue to estimate the qualitative change in adipose tissue in various malignant diseases [ 22 , 23 , 24 , 25 , 26 , 40 ]. Adipose tissue with increased CT-attenuation on non-contrast enhanced CT was found to show increased extracellular matrix fibrosis and small adipocytes with low lipid content on histopathological evaluation, that are also observed in the adipose tissue with cancer-associated adipocytes [ 10 , 23 , 25 , 32 ].…”