Significance of CT attenuation and F-18 fluorodeoxyglucose uptake of visceral adipose tissue for predicting survival in gastric cancer patients after curative surgical resection

Abstract

Background The purpose of this study was to investigate the prognostic significance of computed tomography (CT) attenuation and F-18 fluorodeoxyglucose (FDG) uptake of visceral adipose tissue (VAT) to predict peritoneal recurrence-free survival (RFS) as well as RFS and overall survival (OS) in patients with advanced gastric cancer (AGC). Methods We retrospectively enrolled 117 patients with AGC who underwent staging FDG positron emission tomography (PET)/CT and subsequent curative surgical resection. CT attenuation and FDG uptake (SUV) of VAT and maximum FDG uptake of primary tumor (SUVmaxT) were measured from PET/CT images. The relationship of VAT attenuation and SUV with clinico-histopathologic factors and survival was assessed. Results There was a significant positive correlation between VAT attenuation and SUV (p < 0.001, r = 0.799). In correlation analyses, both VAT attenuation and SUV showed significant positive correlations with T stage, TNM stage, tumor size, and platelet-to-lymphocyte ratio (p < 0.05), and patients who experienced recurrence during the first 3-year after surgery had significantly higher VAT attenuation and SUV than those who had no recurrence (p < 0.05). Patients with high VAT attenuation and SUV showed significantly worse RFS, peritoneal RFS, and OS than those with low values (p < 0.05). On multivariate survival analysis, VAT attenuation was significantly associated with peritoneal RFS and OS and VAT SUV was significantly associated with OS (p < 0.05). Conclusions CT attenuation and FDG uptake of VAT on staging FDG PET/CT were correlated with tumor characteristics and were significant predictive factors for peritoneal RFS and OS in patients with AGC.

Fat density is a novel prognostic marker in patients with esophageal cancer

“…Similar results were obtained in extremity sarcoma, prostate cancer, pancreatic adenocarcinoma and head and neck cancer [14,17,33,34]. Notably, the prognostic impact of fat tissue attenuation was also assessed in a retrospective study of gastric cancer [16]. In this study, high VAT density patients showed worse OS and relapse-free survival compared to patients with low values.…”

“…Hence, Dahlman and others propose that adipose tissues of higher density would be composed of shrunken adipocytes, increased fibrosis and decreased fat cell volume, resulting from changes in extracellular matrix pathway regulations. These events would occur following adipose tissue remodeling associated with aging, which presents overlapping features with cancer-associated wasting [30,31], or pathological conditions such as obesity or cancer [16].…”

“…This is in line with results in pancreatic and gastric cancers, in which no correlation was found either. Nevertheless, another inflammatory marker, the Platelet-to-Lymphocyte Ratio (PLR) showed significant positive yet weak correlation with VAT density in gastric cancer, suggesting that CRP may not be a reliable predictor of adipose tissue quality [16]. Other inflammatory markers such as TNF-a and IL-6 were also associated with adipose tissue density.…”

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].…”

“…In addition to the quantity of adipose tissue, recent studies have employed CT-attenuation on non-contrast enhanced CT images and 18 F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) to investigate the clinical value of qualitative characteristics of adipose tissue in cancer patients [22,23]. These two imaging parameters were found to be related to fibrotic and inflammatory changes in adipose tissue and were significantly associated with the prognosis of several malignant diseases [22][23][24][25]. Considering the significant in vitro interaction between PPAT and prostate cancer cells [10,14,17], qualitative characteristics of PPAT on imaging studies may be associated with clinical characteristics and progression of prostate cancer.…”