Visceral Obesity in Predicting Oncologic Outcomes of Localized Renal Cell Carcinoma

Abdominal fat distribution in endometrial cancer: from diagnosis to follow-up

BACKGROUND

The objective of this study is to quantify abdominal obesity markers from computed tomography (CT) scans at primary diagnosis and follow-up in a large endometrial cancer cohort, and to assess temporal change in obesity markers in relation to surgicopathological patient characteristics and outcome.

METHODS

Total- (TAV), subcutaneous- (SAV), visceral (VAV) abdominal fat volumes, and visceral-to-total fat percentage (VAV%) were derived from CT scans acquired in an endometrial cancer patient cohort at primary diagnosis (nprimary=293). Temporal (delta, δ) changes in CT obesity markers from primary diagnosis to follow-up were assessed for all patients with a follow-up CT 13 (7, 19) [median (interquartile range)] months after diagnosis (nfollow-up=152/293 patients). The CT obesity markers were assessed in relation to clinicopathological features and progression-free survival (PFS) using Mann-Whitney U-test, and Cox hazard ratios (HRs), respectively.

RESULTS

At primary diagnosis, VAV% was the only marker significantly associated with high-risk histology (median of 33% for endometrioid endometrial carcinoma (EEC) grade 1-2, 36% for EEC grade 3 and 36% for non-endometrioid EC, p = 0.003), myometrial invasion (MI) (median of 34% for MI < 50% vs. 35% for MI ≥ 50%, p = 0.03) and lymphovascular space invasion (LVSI) (median of 34% for no LVSI vs. 36% for LVSI, p = 0.009). High VAV% (≥ 35%) also predicted poor PFS both in univariable analysis (HR = 1.8, p = 0.02), and when stratified for surgicopathological FIGO stage (HR = 3.1, p = 0.03). At follow-up, median TAV, VAV, SAV, and VAV% were significantly lower than at primary diagnosis (p < 0.001 for all). Furthermore, patients with progression had larger reductions in visceral fat compartments (δVAV=-24%, δVAV% =-3%), than patients with no progression (δVAV=-17%, δVAV%=-2%, p ≤ 0.006 for both).

CONCLUSION

Visceral abdominal obesity (high VAV%) is associated with high-risk histologic features, myometrial invasion, and poor prognosis. Furthermore, high visceral fat loss during/following therapy is associated with disease progression.

The Prognostic Value of Body Composition Analysis on Non-Enhanced CT for Risk Stratification in Gastrointestinal Stromal Tumors: A Retrospective Study

IntroductionContrast-enhanced computed tomography (CT) is the primary imaging modality for accurate risk stratification in gastrointestinal stromal tumors (GISTs). However, contrast-enhanced CT may not always be accessible or suitable for all patients undergoing risk assessment of GISTs. Therefore, this study explored the use of non-enhanced CT imaging for assessing body composition in patients with GISTs to preoperatively predict risk stratification.MethodsWe retrospectively analyzed 233 patients with GISTs who met the inclusion criteria. Pretreatment complete abdominal CT images from these patients were processed and analyzed using the Siemens Syngo imaging system. The data were subsequently organized and analyzed using the SPSS software (version 26.0).ResultsThrough two independent samples t-tests, Mann-Whitney U tests, and chi-square tests (including corrected chi-square tests and Fisher's exact tests), the intermediate-high risk group exhibited a lower visceral fat index (VFI) and higher tumor volumes and proportions of necrosis (P < .05), compared to the low-risk group (P < .05). No statistically significant differences were observed in the other indicators. Our research demonstrates that tumor volume is positively correlated with the National Institutes of Health (NIH) classification and exhibits the highest specificity among the four models (specificity = 0.735). However, its sensitivity is lower than that of the combined model (sensitivity = 0.803) and the VFI model (sensitivity = 0.972).ConclusionBased on the vascular abundance index, tumor volume, and necrosis status observed in the CT plain scan images of patients with GIST, a comprehensive predictive model was developed. This model can accurately predict the NIH grade of stromal tumors, thereby providing a robust basis for formulating effective treatment strategies and improving the prognosis of patients with GISTs who cannot undergo contrast-enhanced CT.

CT assessment of liver fat fraction and abdominal fat composition can predict postoperative liver metastasis of colorectal cancer

OBJECTIVE

The aim of this study is to investigate the clinical value of liver fat fraction assessed by CT(CT-LFF) and abdominal fat components. We focus on predicting liver metastasis (LM) after colorectal cancer (CRC) surgery.

METHODS

Clinical and imaging data from 79 patients who underwent radical CRC surgery between January 2019 and December 2021 were retrospectively collected. Semi-automatic software was used to quantify the area of different body tissues at the level of the third lumbar vertebra, and liver fat fraction was calculated based on the CT values. Patients were grouped according to BMI, tumor grade, T stage, N stage, vascular invasion (VI), perineural invasion (PNI), and preoperative levels of CEA and CA199. A multivariate logistic regression model was used to identify independent risk factors for early LM after surgery. The diagnostic performance was assessed using the receiver operating characteristic analysis with 5-fold cross-validation. The Kaplan-Meier method was used to draw survival curves, and Log-Rank test was used for survival analysis.

RESULTS

The study found that the occurrence of LM after CRC surgery was significantly associated with CA199 positivity, VI, PNI, N1-2 stage, CT-LFF, VAT index (VATI). Multivariate logistic regression analysis showed that CA199 positivity (OR = 7.659), N1-2 stage (OR = 6.394), CT-LFF (OR = 1.271), VATI (OR = 1.043) were independent risk factors for predicting LM after CRC surgery. The multivariate logistic regression model, constructed using these independent risk factors, demonstrated robust predictive performance across 5-fold cross-validations, with an average AUC of 0.898 (95 % CI: 0.828-0.969). Survival analysis showed a significant difference in liver metastasis-free survival rates between the high-risk and low-risk groups (P < 0.001).

CONCLUSION

CT-LFF and VATI assessed by CT are independent risk factors for predicting LM after CRC surgery. The multivariate prediction model combining CA199 and N stage shows high predictive performance.

Development of a CT-assessed adiposity nomogram for predicting outcome in localized ccRCC

PURPOSE

This study aimed to develop and validate a computed tomography-based nomogram assessing visceral and subcutaneous adiposity for predicting outcomes in localized clear cell renal cell carcinoma (ccRCC).

METHODS

A cohort of 364 patients with pathologically confirmed ccRCC participated in this retrospective study, with 254 patients assigned to the training set and 110 to the validation set (a 7:3 distribution ratio). The adipose score (AS) was generated using the least absolute shrinkage and selection operator Cox regression. Subsequently, a nomogram was constructed by integrating the clinical independent predictor with the AS to predict disease-free survival (DFS) in localized ccRCC after surgery. The performance of the nomogram was compared with the University of California, Los Angeles, Integrated Staging System (UISS), and the Stage, Size, Grade, and Necrosis (SSIGN) score.

RESULTS

In both the training and validation cohorts, the nomogram exhibited superior discrimination compared to SSIGN and UISS (C-index: 0.897 vs. 0.781 vs. 0.776 in the training cohort, and 0.752 vs. 0.596 vs. 0.686 in the validation cohort; 5 year AUC: 0.907 vs. 0.805 vs. 0.820 in the training cohort, and 0.832 vs. 0.577 vs. 0.726 in the validation cohort). Decision curve analysis (DCA) revealed a superior net benefit across a wider range of threshold probabilities for predicting 5 year DFS compared to UISS and SSIGN scores.

CONCLUSIONS

The developed prognostic nomogram demonstrated high accuracy and overall superior performance compared to existing prognostic models.

A Review of the Paradigmatic Role of Adipose Tissue in Renal Cancer: Fat Measurement and Tumor Behavior Features

(1) Background: Renal-cell carcinoma (RCC) incidence has been steadily rising, with obesity identified as a potential risk factor. However, the relationship between obesity and RCC prognosis remains unclear. This systematic review aims to investigate the impact of different adipose tissue measurements on RCC behavior and prognosis. (2) Methods: A search of MEDLINE databases identified 20 eligible studies focusing on various fat measurements, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), perirenal adipose tissue (PRAT), and the Mayo adhesive probability (MAP) score. (3) Results: The review revealed conflicting findings regarding the association between adipose tissue measurements and RCC outcomes. While some studies suggested a protective role of certain fat deposits, particularly VAT, against disease progression and mortality, others reported contradictory results across different adipose metrics and RCC subtypes. (4) Conclusions: Methodological variations and limitations, such as retrospective designs and sample size constraints, pose challenges to standardization and generalizability. Further research is needed to understand these associations better and establish standardized approaches for adiposity assessment in RCC patients, which could inform clinical practice and therapeutic decision-making.

Skeletal muscle and visceral adipose radiodensities are pre-surgical, non-invasive markers of aggressive kidney cancer

INTRODUCTION

Most studies on body composition in kidney cancer have been conducted among patients with metastatic disease. Given that aggressive tumours can adversely impact body composition and even non-metastatic tumours can be aggressive, we evaluated associations between pre-surgical body composition features and tumour pathological features in patients with non-metastatic clear cell renal cell cancer (ccRCC).

METHODS

The Resolve Cohort consists of 1239 patients with non-metastatic ccRCC who underwent nephrectomy at Memorial Sloan Kettering Cancer Center between 2000 and 2020. The cross-sectional areas and radiodensities of skeletal muscle, visceral adipose, and subcutaneous adipose tissues were determined from pre-surgical computed tomography (CT) scans at the third lumbar vertebrae using Automatica software. Pearson's correlation coefficients describe inter-relationships among BMI and body composition variables, while odds ratios (OR) and 95% confidence intervals (CI) estimate associations between continuous body composition features (per 1-standard deviation) and advanced stage (Stage III vs. Stages I-II) and high Fuhrman grade (Grades 3-4 vs. 1-2) from multivariable logistic regression models that considered the potential impact of biological sex, contrast enhanced CTs, and early age at onset of ccRCC.

RESULTS

The cohort was predominantly male (69%), white (89%), and had a median age of 58. The proportion of patients presenting with advanced stage and high-grade disease were 31% and 51%, respectively. In models that adjusted for demographics and all body composition variables simultaneously, decreasing skeletal muscle radiodensity (i.e., more fat infiltration) but increasing visceral adipose tissue radiodensity (i.e., more lipid depletion) were associated with advanced tumour features. Per 8.4 HU decrease in skeletal muscle radiodensity, the odds of presenting with advanced stage was 1.61 (95% CI: 1.34-1.93). Per 7.22 HU increase in visceral adipose tissue radiodensity, the odds of presenting with advanced stage was 1.45 (95% CI: 1.22-1.74). Skeletal muscle index (i.e., sarcopenia) was not associated with either tumour feature. Similar associations were observed for Fuhrman grade, a more direct marker of tumour aggressiveness. Associations did not differ by sex, contrast use, or age at onset of ccRCC.

CONCLUSIONS

Lipid infiltrated skeletal muscle, but lipid depleted visceral adipose tissue were independently associated with advanced tumour features in non-metastatic ccRCC. Findings highlight the importance of evaluating the full range of body composition features simultaneously in multivariable models. Interpreting pre-surgical CTs for body composition for patients may be a novel and non-invasive way to identify patients with aggressive renal tumours, which is clinically relevant as renal biopsies are not routinely performed.

Fat Matters: Exploring Cancer Risk through the Lens of Computed Tomography and Visceral Adiposity

Obesity is an established risk factor for cancer. However, conventional measures like body mass index lack precision in assessing specific tissue quantities, particularly of the two primary abdominal fat compartments, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Computed tomography (CT) stands as the gold standard for precisely quantifying diverse tissue types. VAT, distinguished by heightened hormonal and metabolic activity, plays a pivotal role in obesity-related tumor development. Excessive VAT is linked to aberrant secretion of adipokines, proinflammatory cytokines, and growth factors, fostering the carcinogenesis of obesity-related tumors. Accurate quantification of abdominal fat compartments is crucial for understanding VAT as an oncological risk factor. The purpose of the present research is to elucidate the role of CT, performed for staging purposes, in assessing VAT (quantity and distribution) as a critical factor in the oncogenesis of obesity-related tumors. In the field of precision medicine, this work takes on considerable importance, as quantifying VAT in oncological patients becomes fundamental in understanding the influence of VAT on cancer development-the potential "phenotypic expression" of excessive VAT accumulation. Previous studies analyzed in this research showed that VAT is a risk factor for clear cell renal cell carcinoma, non-clear cell renal cell carcinoma, prostate cancer, and hepatocarcinoma recurrence. Further studies will need to quantify VAT in other oncological diseases with specific mutations or gene expressions, in order to investigate the relationship of VAT with tumor genomics.

Association of sex-specific abdominal adipose tissue with WHO/ISUP grade in clear cell renal cell carcinoma

OBJECTIVES

To explore the association between computed tomography (CT)-measured sex-specific abdominal adipose tissue and the pathological grade of clear cell renal cell carcinoma (ccRCC).

METHODS

This retrospective study comprised 560 patients (394 males and 166 females) with pathologically proven ccRCC (467 low- and 93 high-grade). Abdominal CT images were used to assess the adipose tissue in the subcutaneous, visceral, and intermuscular regions. Subcutaneous fat index (SFI), visceral fat index (VFI), intermuscular fat index (IFI), total fat index (TFI), and relative visceral adipose tissue (rVAT) were calculated. Univariate and multivariate logistic regression analyses were performed according to sex to identify the associations between fat-related parameters and pathological grade.

RESULTS

IFI was significantly higher in high-grade ccRCC patients than in low-grade patients for both men and women. For male patients with high-grade tumors, the SFI, VFI, TFI, and rVAT were significantly lower, but not for female patients. In both univariate and multivariate studies, the IFI continued to be a reliable and independent predictor of high-grade ccRCC, regardless of sex.

CONCLUSIONS

Intermuscular fat index proved to be a valuable biomarker for the pathological grade of ccRCC and could be used as a reliable independent predictor of high-grade ccRCC for both males and females.

CRITICAL RELEVANCE STATEMENT

Sex-specific fat adipose tissue can be used as a new biomarker to provide a new dimension for renal tumor-related research and may provide new perspectives for personalized tumor management decision-making approaches.

KEY POINTS

• There are sex differences in distribution of subcutaneous fat and visceral fat. • The SFI, VFI, TFI, and rVAT were significantly lower in high-grade ccRCC male patients, but not for female patients. • Intermuscular fat index can be used as a reliable independent predictor of high-grade ccRCC for both males and females.

Prediction of Fuhrman nuclear grade for clear cell renal carcinoma by a multi-information fusion model that incorporates CT-based features of tumor and serum tumor associated material

PURPOSE

Prediction of Fuhrman nuclear grade is crucial for making informed herapeutic decisions in clear cell renal cell carcinoma (ccRCC). The current study aimed to develop a multi-information fusion model utilizing computed tomography (CT)-based features of tumors and preoperative biochemical parameters to predict the Fuhrman nuclear grade of ccRCC in a non-invasive manner.

METHODS

218 ccRCC patients confirmed by histopathology were retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to identify independent predictors and establish a model for predicting the Fuhrman grade in ccRCC. The predictive performance of the model was evaluated using receiver operating characteristic (ROC) curves, calibration, the 10-fold cross-validation method, bootstrapping, the Hosmer-Lemeshow test, and decision curve analysis (DCA).

RESULTS

R.E.N.A.L. Nephrometry Score (RNS) and serum tumor associated material (TAM) were identified as independent predictors for Fuhrman grade of ccRCC through multivariate logistic regression. The areas under the ROC curve (AUC) for the multi-information fusion model composed of the above two factors was 0.810, higher than that of the RNS (AUC 0.694) or TAM (AUC 0.764) alone. The calibration curve and Hosmer-Lemeshow test showed the integrated model had a good fitting degree. The 10-fold cross-validation method (AUC 0.806) and bootstrap test (AUC 0.811) showed the good stability of the model. DCA demonstrated that the model had superior clinical utility.

CONCLUSION

A multi-information fusion model based on CT features of tumor and routine biochemical indicators, can predict the Fuhrman grade of ccRCC using a non-invasive approach. This model holds promise for assisting clinicians in devising personalized management strategies.

Impact of Quantitative Computed Tomography-Based Analysis of Abdominal Adipose Tissue in Patients with Lymphoma

Quantitative abdominal adipose tissue analysis is important for obtaining information about prognosis and clinical outcomes on a wide array of diseases. In recent years, the effects of abdominal adipose tissue compartments in patients with lymphoma and the changes in their distribution after therapies have been studied. This information could facilitate the improvement of therapies in patients with lymphoma, to prevent or treat both visceral obesity and sarcopenia. Opportunistic analysis of body composition on computed tomography (CT) images might contribute to the improvement of patient management and clinical outcomes together with implementation of targeted patient-tailored therapies. The purpose of this literature review is to describe the role of CT to evaluate abdominal adipose tissue quantity and distribution in patients with lymphoma.

Sex Differences in Renal Cell Carcinoma: The Importance of Body Composition

PURPOSE

To examine sex-specific differences in renal cell carcinoma (RCC) in relation to abdominal fat accumulation, psoas muscle density, tumor size, pathology, and survival, and to evaluate possible associations with RCC characteristics and outcome.

METHODS

A total of 470 patients with RCC who underwent nephrectomy between 2006 and 2019 were included in this retrospective study. Specific characteristics of RCC patients were collected, including sex, height, tumor size, grade, and data on patient survival, if available. Abdominal fat measurements and psoas muscle area were determined at the level of L3 (cm²).

RESULTS

Women had a higher subcutaneous (p < 0.001) and men had a higher visceral fat area, relative proportion of visceral fat area (p < 0.001), and psoas muscle index (p < 0.001). Logistic regression analysis showed an association between higher psoas muscle index and lower grade tumors [women: odds ratio (OR) 0.94, 95% confidence interval (CI) 0.89-0.99, p = 0.011; men: OR 0.97 (95% CI, 0.95-0.99, p = 0.012]. Univariate regression analysis demonstrated an association between psoas muscle index and overall survival (women: OR 1.41, 95% CI 1.03-1.93, p = 0.033; men: OR 1.62 (95% CI, 1.33-1.97, p < 0.001). In contrast, there were no associations between abdominal fat measurements and tumor size, grade, or survival. Also, there were no sex-specific differences in tumor size or tumor grades.

CONCLUSIONS

A higher preoperative psoas muscle index was independently associated with overall survival in RCC patients, with a stronger association in men compared with women. In addition, the psoas muscle index showed an inverse association with tumor grade, whereby this association was slightly more pronounced in women than in men.

Relationship between Androgen Deprivation Therapy and Abdominal Adipose Tissue

The role of androgens in body composition is well known. Androgen deprivation therapy (ADT) has shown beneficial effects in the treatment of advanced prostate cancer (PCa). Given that androgens are important for the homeostasis of different organs, the effects of ADT can affect body composition and therefore adipose tissue. Computed tomography (CT) and magnetic resonance imaging (MRI) are non-invasive methods that allow for quantification of the different fat compartments. In this review we describe the effects of ADT on abdominal adipose tissue in PCa patients.

Association of visceral and subcutaneous adiposity with tumor stage and Fuhrman grade in renal cell carcinoma

Higher BMI has been associated with lower tumor stage and grade and improved survival in renal cell cancer (RCC). BMI cannot distinguish between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). We examined associations of BMI, VAT, SAT, total adipose tissue (TAT) and relative VAT (rVAT) with tumor stage and grade in RCC patients. In a Dutch multicenter population-based historical cohort study 1039 RCC patients diagnosed between 2008 and 2012 were assessed for VAT and SAT using Computed Tomography images at L3. Sex-stratified multinomial logistic regression analyses were performed (linearly per 10-unit increase) between BMI, VAT, SAT, TAT and relative VAT (rVAT) with tumor stage and Fuhrman grade. Higher VAT, TAT and rVAT were associated with a lower risk of stage IV versus stage I in males (OR 0.93; 95%CI 0.91–0.96, OR 0.95; 95%CI 0.93–0.98, OR 0.97; 95%CI 0.96–0.99, respectively). Females showed similar associations, but only higher VAT was statistically significantly associated with reduced risk of stage IV (OR 0.95 95%CI 0.89–1.00). No associations with grade, SAT or BMI were found. In conclusion, higher VAT and TAT was associated with lower risk of stage IV RCC. This might be due to weight loss or cancer cachexia in stage IV patients.

Adiposity and cancer survival: a systematic review and meta-analysis

PURPOSE

The increasing availability of clinical imaging tests (especially CT and MRI) that directly quantify adipose tissue has led to a rapid increase in studies examining the relationship of visceral, subcutaneous, and overall adiposity to cancer survival. To summarize this emerging body of literature, we conducted a systematic review and meta-analysis of imaging-measured as well as anthropometric proxies for adipose tissue distribution and cancer survival across a wide range of cancer types.

METHODS

Using keywords related to adiposity, cancer, and survival, we conducted a systematic search of the literature in PubMed and MEDLINE, Embase, and Web of Science Core Collection databases from database inception to 30 June 2021. We used a random-effect method to calculate pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI) within each cancer type and tested for heterogeneity using Cochran's Q test and the I2 test.

RESULTS

We included 203 records for this review, of which 128 records were utilized for quantitative analysis among 10 cancer types: breast, colorectal, gastroesophageal, head and neck, hepatocellular carcinoma, lung, ovarian, pancreatic, prostate, and renal cancer. We found that imaging-measured visceral, subcutaneous, and total adiposity were not significantly associated with increased risk of overall mortality, death from primary cancer, or cancer progression among patients diagnosed with these 10 cancer types; however, we found significant or high heterogeneity for many cancer types. For example, heterogeneity was similarly high when the pooled HRs (95% CI) for overall mortality associated with visceral adiposity were essentially null as in 1.03 (0.55, 1.92; I2 = 58%) for breast, 0.99 (0.81, 1.21; I2 = 71%) for colorectal, versus when they demonstrated a potential increased risk 1.17 (0.85, 1.60; I2 = 78%) for hepatocellular carcinoma and 1.62 (0.90, 2.95; I2 = 84%) for renal cancer.

CONCLUSION

Greater adiposity at diagnosis (directly measured by imaging) is not associated with worse survival among cancer survivors. However, heterogeneity and other potential limitations were noted across studies, suggesting differences in study design and adiposity measurement approaches, making interpretation of meta-analyses challenging. Future work to standardize imaging measurements and data analyses will strengthen research on the role of adiposity in cancer survival.

Comparison of perinephric fat measurements between malignant and benign renal tumours

Objective

To investigate different parameters derived from the quantity and quality of perinephric fat, and to compare their effectiveness in predicting the malignant pathology of renal tumours.

Methods

Data from patients diagnosed with renal tumour between April 2014 and December 2020 were retrospectively reviewed, and patients were categorized into malignant or benign tumour groups. Fat parameters, including perinephric fat volume (PFV), perinephric fat area (PFA), perinephric fat thickness (PFT), and Mayo adhesive probability (MAP) score were measured using abdominal computed tomography scans. Between-group differences were assessed by analysis of variance and χ²-test. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of perinephric fat parameters in diagnosing malignancy.

Results

A total of 109 patients were included. MAP score, PFV, PFA, and PFT were significantly increased in the malignant versus benign tumour group, and after correction for body mass index (BMI), the indexed PFV/BMI, PFA/BMI, and PFT/BMI values remained significantly higher in the malignant tumour group. All parameters showed fair predictivity of malignancy, with comparable area under the curve values in the ROC curve.

Conclusion

An increased amount of perinephric fat is predictive of malignant pathology for renal tumours. The predictive accuracy for each perinephric fat parameter remained fair after correcting for BMI.

Perirenal Fat as a New Independent Prognostic Factor in Patients With Surgically Treated Clear Cell Renal Cell Carcinoma

INTRODUCTION

Recently increasing evidence has suggested that obesity is associated with the development and prognosis of renal cell carcinoma. The aim of the study was to investigate the association between different obesity measurements and overall survival in patients with surgically treated clear cell renal cell carcinoma.

PATIENTS AND METHODS

The data of 342 consecutive patients who underwent radical or partial nephrectomy at Peking University People's Hospital from January 2009 to November 2014 were retrospectively reviewed. Median follow-up was 82 months. The association between different obesity measurements and overall survival was evaluated using the Kaplan-Meier method and Cox regression models.

RESULTS

In univariate Cox regression analyses, perirenal fat accumulation was significantly associated with overall survival (HR: 2.271; 95% CI: 1.311-3.935; P = .003), as well as age, sex, clinical manifestation, surgical option, tumor size, and grade. The other obesity measurements, including body mass index, waist circumference, total adipose tissue, visceral adipose tissue, and percentage of visceral adipose tissue, were not assessed as prognostic indicators of overall survival in this study (P > .05). After adjusting for age, sex, clinical manifestation, surgical option, tumor size, T stage, and tumor grade, perirenal fat accumulation was still identified as an independent predictor of overall survival (HR: 2.264; 95% CI: 1.305-3.926; P == .004). The results of Kaplan-Meier model also revealing that patients with higher percentage of perirenal fat showed poorer overall survival (P == .003).

CONCLUSION

Higher percentage of perirenal adipose tissue is independently associated with increased mortality risk in surgically treated clear cell renal cell carcinoma.

Usefulness of the mayo adhesive probability score as a predictive factor for renal function deterioration after partial nephrectomy: a retrospective case-control study

PURPOSE

Whether the Mayo adhesive probability score, an index of the perinephric fat environment, could be a predictive factor for renal function deterioration after partial nephrectomy was investigated.

METHODS

A retrospective case-control study of 78 patients who underwent laparoscopic partial nephrectomy was performed. An estimated glomerular filtration rate preservation rate at ≤ 90% at 3 months after surgery was defined as postoperative renal function deterioration. These patients were divided into two groups (non-deterioration and deterioration groups). Patient factors including Mayo adhesive probability scores (both tumor and unaffected sides) and surgical factors were evaluated to identify the predictors for postoperative renal function deterioration. The statistical analysis used univariate and multivariate logistic regression analyses.

RESULTS

Thirty-seven (47.4%) patients had postoperative renal function deterioration after partial nephrectomy. Univariate analysis identified Mayo adhesive probability score on the unaffected side (p = 0.02), and warm ischemia time (p < 0.01) as predictors of postoperative renal function deterioration. On multivariate analyses, Mayo adhesive probability score on the unaffected side (odds ratio: 1.38 [1.05-1.79], p = 0.02) and warm ischemia time (odds ratio: 1.04 [1.01-1.07], p < 0.01) were significantly associated with postoperative renal function deterioration as same as univariate analysis. On receive operating characteristic curve analysis, Mayo adhesive probability score on the unaffected side (cutoff value 1.5; p = 0.02) and warm ischemia time (cutoff value 26.5 min; p = 0.01) were significant predictors of renal function deterioration 3 month after surgery.

CONCLUSION

The Mayo adhesive probability score on the unaffected side and warm ischemia time are useful predictors for renal function deterioration after partial nephrectomy.

TRIAL REGISTRATION NUMBER

2019-249, January 21st, 2019, retrospectively registered.

Association between visceral adiposity and DDX11 as a predictor of aggressiveness of small clear-cell renal-cell carcinoma: a prospective clinical trial

Background

Visceral fat produces several hormones and cytokines associated with carcinogenesis and tumor progression. Herein, we investigated the association between visceral adiposity and target-gene mRNA expression in patients with localized small clear-cell renal-cell carcinoma (ccRCC).

Methods

We included 200 patients with localized clinical T1a stage ccRCC who had undergone nephrectomy from November 2018 to November 2020 in a prospective clinical trial (NCT03694912). Visceral, subcutaneous, and total adipose tissue in these patients was measured via preoperative computerized tomography of the mid-third lumbar vertebra region. We then examined the association between adiposity and the mRNA levels of PBRM1, BAP1, SETD2, KDM5C, FOXC2, CLIP4, AQP1, DDX11, BAIAP2L1, and TMEM38B in matched frozen tumor tissues and plasma samples.

Results

Upon the stratification of patients into quartiles according to their relative visceral adiposity, high visceral adiposity was found to be significantly associated with low ISUP grade (P = 0.004). Multivariate logistic regression analysis revealed a significant association between frozen tissue DDX11 expression and high visceral adiposity (OR 0.676, 95% CI 0.587–0.779, P < 0.001). Moreover, frozen tissue DDX11 expression was significantly associated with high ISUP grade (OR 1.556, 95% CI 1.223–1.981, P < 0.001). The frozen tissue mRNA expression of DDX11 was identified as a biomarker for visceral adiposity and cancer aggressiveness.

Conclusions

The results obtained herein will aid in inferring the aggressiveness of small ccRCCs, represented by ISUP nuclear grade, in clinical practice. Our findings indicated that DDX11 and visceral fat play active roles in small ccRCC. These roles should be examined in future studies for the possible use of DDX11 and visceral fat as prognostic biomarkers in the treatment of patients with ccRCC.

Trial registration

ClinicalTrials.gov, NCT03694912, Registered 3 October 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-021-00251-y.

The impact of visceral adipose tissue on post -operative renal Function after Radical Nephrectomy for renal cell carcinoma

BACKGROUND

The objective of this study was to evaluate the usefulness of pre-operative visceral (VAT) and subcutaneous adipose tissue (SAT) evaluation in the prediction of Acute Kidney Injury (AKI) and decrease of eGFR at 12 months after radical nephrectomy (RN).

METHODS

We relied on 112 patients who underwent RN between January 2010 and March 2017 at a single institution. Images from the pre-operatory CT scan were analyzed and both SAT and VAT assessments were carried out on a cross-sectional plane. eGFR was measured before surgery, at 7 days, and 12 months after surgery. ROC analysis was used to compare the diagnostic value of BMI, VAT ratio, and abdominal circumference in predicting AKI. Logistic regression models were fitted to predict the new onset of AKI, and the progression from chronic kidney disease (CKD) stage 1-3a to CKD stage 3b or from 3b to 4 at 12 months follow-up. Two logistic regression models were also performed to assess the predictors for AKI and CKD stage progression. The predictive accuracy was quantified using the receiver operating characteristic-derived area under the curve.

RESULTS

Sixty-six patients (58.9%) had AKI after RN. Thirty-five (31.3%) patients were upgraded to CKD IIIb or from CKD stage IIIb to CKD IV. In the ROC analysis, VAT% performed better than the BMI and abdominal circumference (AUC = 0.66 vs 0.49 and 0.54, respectively). At multivariable analyses, VAT reached an independent predictor status for AKI (OR: 1.03) and for CKD stage at 12 months Follow-up (OR: 1.05). Inclusion of VAT% into the multivariable models was associated with the highest accuracy both for AKI (AUC = 0.700 vs 0.570) and CKD stage progression (AUC = 0.848 vs 0.800).

CONCLUSIONS

In patients undergoing RN, preoperative visceral adipose tissue ratio significantly predicts AKI incidence and is significantly predictive of 12 months CKD stage worsening.

Visceral Adiposity as a Significant Predictor of Sunitinib-Induced Dose-Limiting Toxicities and Survival in Patients with Metastatic Clear Cell Renal Cell Carcinoma

Sunitinib is a first-line treatment for metastatic renal cell carcinoma (mRCC). Little is known about the predictive factors of sunitinib-induced dose-limiting toxicity (DLT) in Asian populations. We investigated whether body composition predicts sunitinib-induced DLT. We retrospectively reviewed sunitinib-treated Korean patients with clear cell mRCC from eight institutions. Body composition was measured using computed tomography. DLT was defined as any adverse event leading to dose reduction or treatment discontinuation. Univariate analysis was used to compare body composition indices, and logistic regression analyses were performed for factors predicting early DLT. Overall, 111/311 (32.5%) of patients experienced DLT. Significant differences were observed in the subcutaneous adipose tissue index (SATI; p = 0.001) and visceral adipose tissue index (VATI; p < 0.001) between patients with and without DLT. Multivariate analyses revealed that VATI (odds ratio: 1.013; p = 0.029) was significantly associated with early DLT. Additionally, 20% of patients who had a body mass index (BMI) greater than 23 kg/m² and a low VATI experienced DLT, whereas 34.3% of the remaining groups had DLT (p = 0.034). Significant differences were observed for median progression-free survival (13.0 vs. 26.0 months, respectively; p = 0.006) between patients with low and high VATI. Visceral adiposity was a significant predictor of sunitinib-associated DLT and survival. Patients with a low VATI and a BMI greater than 23 kg/m² experienced lower DLTs.

Clear cell renal cell carcinoma: the value of sex-specific abdominal visceral fat measured on CT for prediction of Fuhrman nuclear grade

OBJECTIVE

To explore whether sex-specific abdominal visceral fat composition on CT can predict the Fuhrman nuclear grade of clear cell renal cell carcinoma (ccRCC).

METHODS

One hundred seventy-one patients (123 males and 48 females) from four hospitals (multicentre group) and 159 patients (109 males and 50 females) from the cancer imaging archive (TCIA-KIRC group) with pathologically proven ccRCC (multicentre: 124 low grade and 47 high grade; TCIA-KIRC: 79 low grade and 80 high grade) were retrospectively included. Abdominal fat was segmented into subcutaneous fat area (SFA) and visceral fat area (VFA) on CT using ImageJ. The total fat area (TFA) and relative VFA (rVFA) were then calculated. Clinical characteristics (age, sex, waist circumference and maximum tumour diameter) were also assessed. Univariate and multivariate logistic regression analyses were performed to identify the association between general or sex-specific visceral fat composition and Fuhrman grade.

RESULTS

Females with high-grade ccRCC from the multicentre group had a higher rVFA (42.4 vs 31.3, p = 0.001) than those with low-grade ccRCC after adjusting for age. There was no significant difference in males. The rVFA remained a stable and independent predictor for females high-grade ccRCC in both the univariate (multicentre: OR 1.205, 95% CI 1.074-1.352, p = 0.001; TCIA-KIRC: OR 1.171, 95% CI 1.016-1.349, p = 0.029) and multivariate (multicentre: OR 1.095, 95% CI 1.024-1.170, p = 0.003; TCIA-KIRC: OR 1.103, 95% CI 1.024-1.187, p = 0.010) models.

CONCLUSIONS

Sex-specific visceral fat composition has different values for predicting high-grade ccRCC and could be used as an independent predictor for females with high-grade ccRCC.

KEY POINTS

• Visceral fat measurement (rVFA) as an independent predictor for high-grade ccRCC had good predictive power in females, but not in males. • Sex-specific visceral fat composition was significantly associated with high-grade ccRCC in females only. • The rVFA could be considered one of the risk factors for high-grade ccRCC for females.

Increased visceral adipose tissue in clear cell renal cell carcinoma with and without peritumoral collateral vessels

OBJECTIVE

The excessive amount of adipose tissue, mainly visceral, determines adiposopathy. With respect to oncogenesis, visceral adipose tissue (VAT) releases secretes adipokines, proinflammatory citokines and growth factors, considered mediating molecules in the development of obesity-related tumors. In this study, we quantify VAT in male patients with clear cell renal cell carcinoma (ccRCC) subgrouped according to the presence or absence of peritumoral collateral vessels.

METHODS

in this retrospective study, we enrolled 141 male caucasian patients divided into 2 groups: the ccRCC group (n = 106) composed of patients with ccRCC and control group (n = 35). The ccRCC group was further divided into two subgroups: the ccRCCa subgroup which showed absence of collateral vessels (n = 48) and ccRCCp subgroup with collateral vessels (n = 58).Total adipose tissue (TAT) area, VAT area and subcutaneous adipose tissue (SAT) area were measured in the groups and subgroups. VAT/SAT ratio was calculated for each subject.

RESULTS

Statistically significant differences were obtained between ccRCC group and control group for TAT area (p < 0.005), VAT area (p < 0.005) and SAT area (p = 0.01). Between ccRCCa subgroup and control group for TAT area (p < 0.001), VAT area (p = 0.005) and SAT area (p = 0.001). Between ccRCCp subgroup and control group for TAT area (p = 0.01) and VAT area (p = 0.01).

CONCLUSION

This study confirms the increase of abdominal, especially visceral, adipose tissue in ccRCC patients and demonstrates a significant VAT accumulation in both categories of patients with and without peritumoral collateral vessels.

ADVANCES IN KNOWLEDGE

Visceral adiposity is present in patients with ccRCC regardless the presence of peritumoral collateral vessels, with surprisingly stronger results in the ccRCCa subgroup.

Association of body composition with survival and inflammatory responses in patients with non-metastatic nasopharyngeal cancer

OBJECTIVES

It is unknown whether or not the body composition is correlated with the prognosis and inflammatory response in patients with nasopharyngeal cancer (NPC).

MATERIALS AND METHODS

This cohort included 1767 patients with NPC. Visceral, subcutaneous and intra muscular adipose tissues (VAT, SAT and IMAT), and skeletal muscle index were quantified with computed tomography. We used the optimal stratification to select cut points for VAT, SAT and IMAT. We defined sarcopenia according to a widely used cut-point. The primary endpoint was overall survival (OS). The association between body composition and inflammatory response was also examined.

RESULTS

Low VAT, SAT, IMAT and sarcopenia were observed in 260 (14.7%), 451 (25.5%), 773 (43.7%) and 683 (38.7%) patients, respectively. Low VAT (P < 0.001, hazard ratio [HR], 1.884; 95% confidence interval [CI], 1.436-2.473,) and SAT (P = 0.022, HR, 1.334, 95%CI, 1.043-1.706) were both associated worse survival. IMAT and sarcopenia were not with prognostic value. In multivariate analysis, we found the prognostic value of the VAT (HR: 1.544, 95% CI: 1.128-2.114; P = 0.007) was independent of T stage, N stage, disease stage, lactic dehydrogenase, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), the systemic immune-inflammation index (SII), EBV-DNA and body mass index. We observed higher NLR (P = 0.028) and PLR (P < 0.001) in patients with low SAT. Both low VAT (P = 0.009) and SAT (P = 0.005) were associated with decreased stromal lymphocyte infiltrating intensity.

CONCLUSIONS

Among body composition parameters, VAT was an independent prognostic factor, especially in patients with locally advanced NPC.

The Prognostic Value of Body Fat Components in Metastasis Renal Cell Carcinoma Patients Treated with TKIs

Purpose

To assess the association between body fat components and survival status and tumor response for metastatic renal cell carcinoma (mRCC) patients treated with tyrosine kinase inhibitors (TKIs).

Patients and Methods

Patients with pathologically diagnosed and radiologically indicated mRCC were enrolled into the retrospective study. Three body fat components: total fat accumulation (TFA), visceral fat accumulation (VFA) and subcutaneous fat accumulation (SFA) were measured using standard CT scans. The clinical outcomes included progression-free survival (PFS), overall survival (OS), and tumor response rates. Univariate analysis and multivariate Cox proportion hazard regression models were used to find associated parameters and to calculate the adjusted hazard ratio (HR).

Results

A total of 146 patients were enrolled and the average age of patients was 56.5 years old. According to the univariate analysis, patients with an increased SFA and TFA had a longer PFS and OS. A similar phenomenon was observed among patients with ≥2 increasing body fat components about PFS and OS. As for multivariate analysis, SFA change (p=0.014) or the number of increasing body fat components (p=0.040) were independent indicators to predict PFS. In addition, SFA change (p=0.022) or the number of increasing body fat components (p=0.008) could independently predict OS. Moreover, a better disease control rate (p=0.028) was founded in patients with ≥2 increasing components. In the subgroup of patients with ≥2 metastasis sites, improved OS (p=0.017) and PFS (p=0.027) were found compared to those with <2 increasing components. Further multivariate analysis identified the number of increasing body fat components was an independent factor in predicting PFS (p=0.018) and OS (p=0.029).

Conclusion

Body fat accumulation, such as high SFA or TFA at progression, could improve the survival of patients with mRCC treated with TKIs, especially patients with higher tumor burden. It should be considered as an important parameter to predict the survival status of patients with mRCC.

Is visceral obesity associated with colorectal cancer? The first volumetric study using all CT slices

PURPOSE

We aimed to examine the possible relationship between abdominal adiposity parameters and the presence of colorectal cancer (CRC) and between these adiposity parameters and various histopathologic findings of the tumor.

METHODS

A total of 60 control subjects and 111 CRC patients, 63 with early-stage and 48 with advanced-stage disease, were enrolled. Medical data and abdominopelvic computed tomography (CT) examinations of each study group were retrospectively reviewed. Abdominal adiposity parameters, including visceral adipose tissue (VAT) volume, subcutaneous adipose tissue (SAT) volume, and total adipose tissue (TAT) volume, were calculated on all slices of the CT examinations with specialized software, and results for each study group were compared. Adiposity parameters were also compared with tumor histopathologic findings.

RESULTS

We found lower VAT and higher SAT volumes in advanced-stage CRC patients, compared with the early-stage group. However, this relationship was not statistically significant (P = 0.721 for VAT and P = 0.432 for SAT volumes). We detected significantly lower VAT and SAT volumes in the early-stage CRC group compared with the control group (P = 0.014 for both). There was no significant relationship between TAT volumes and the study groups (P = 0.06). No statistically significant relationship was detected between adipose tissue parameters and histopathologic features of the CRC group (P > 0.05).

CONCLUSION

We found statistically significant lower VAT and SAT volumes in patients with early-stage CRC compared with the control group. Volumetric adipose tissue measurements may be more accurate than area measurements and can easily be performed on abdominopelvic CT examination, which is the routine imaging modality for CRC patients.

Increased visceral adipose tissue in male patients with non-clear cell renal cell carcinoma

BACKGROUND

It is well known that there is a link between obesity and oncogenesis in many sites, including the kidney. Adiposopathy is characterized by an excessive accumulation of adipose tissue, principally visceral, which can lead to adipocyte and adipose tissue-related disorder, promoting metabolic syndrome. Visceral adipocytes secrete growth factors, proinflammatory cytokines and adipokines, regarded as mediating factors associated with the oncogenesis of obesity-related tumors. In this study, we evaluate the relationship between visceral adipose tissue (VAT) and non-clear cell renal cell carcinoma (nccRCC) in male patients.

METHODS

In this retrospective study, two groups were included: nccRCC group and control group. Total adipose tissue (TAT) area, VAT area and subcutaneous adipose tissue (SAT) area were measured in both groups. VAT/SAT ratio was subsequently calculated.

RESULTS

Statistically significant differences between the two groups were found in TAT area (p = 0.05), VAT area (p < 0.01) and VAT/SAT ratio (p < 0.05), while no significant difference was found in SAT area.

CONCLUSIONS

This study demonstrates an increased visceral adipose tissue in male patients with nccRCC.

Elevated CD36 expression correlates with increased visceral adipose tissue and predicts poor prognosis in ccRCC patients

Objective: Growing evidence has proved obesity one of the confirmed important etiologic indicators for renal cell carcinoma (RCC). CD36 is underpinned to be involved in adipose absorption, but its role in clear cell renal cell carcinoma (ccRCC) remains unclear. This study aimed to investigate the mRNA expression of CD36 in anthropometric measures of adipose tissue and defining its value in predicting prognosis in ccRCC patients. Methods: Real-Time qPCR gene expression analysis was detected from 367 paired ccRCC and adjacent normal tissues. Distributions of categorical clinical-pathological data together with levels of CD36 expression were compared with χ²-test in a contingency table. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured by magnetic resonance imaging (MRI) and identified at the level of the umbilicus. Pearson's correlation coefficient was utilized to quantify relations between body mass index (BMI), VAT%, SAT and CD36 expression respectively. Partial likelihood test from univariate and multivariate Cox regression analysis were developed to address the influence of independent factors on progression-free survival (PFS) and overall survival (OS). The Kaplan-Meier method and log-rank test were performed to assess the survival benefits between discrete levels. Results: In the current study, CD36 mRNA was demonstrated highly expressed in ccRCC compared with normal tissues. In addition, CD36 mRNA expression was significantly increased in patients with advanced TNM stage (p=0.003, p<0.001, p<0.001), and high VAT% (p=0.004). Pearson's correlation coefficient indicated that CD36 amplification positively correlated with BMI (r=0.117, p=0.025), VAT% (r=0.465, p<0.001), while negatively associated with SAT (r=-0.296, p=0.002). Median PFS was 60 months and OS was 99 months. Meanwhile, ccRCC patients with elevated CD36 expression held shorter PFS and OS, with hazard ratios [HR; 95% confidence interval (CI)] of 4.873 (3.300-7.196, p<0.001) and 4.610 (2.956-7.189, p<0.001). In 104 cases with available MRI scans, VAT was significantly correlated with poor PFS and OS, with HR of 2.556 (1.036-6.310, p<0.042) and 3.291 (1.034-10.477, p<0.044). A total of 100 significant genes were obtained from GSEA, and CD36 was found involved in the most significant pathways including fatty acid metabolism, UV response, angiogenesis and transforming growth factor beta (TGF-β) signaling pathways. Conclusion: In conclusion, our study first reveal that elevated CD36 mRNA expression is positively correlated to distribution of abdominal adipose, particularly VAT%, which, in addition, notably predicts poor prognosis in ccRCC patients.

The Plausibility of Obesity Paradox in Cancer-Point

In contrast to the convincing evidence that obesity (measured by body mass index, BMI) increases the risk of many different types of cancer, there is an ambiguity in the role of obesity in survival among cancer patients. Some studies suggested that higher BMI decreased mortality risk in cancer patients, a phenomenon called the obesity paradox. The spurious positive association between BMI and cancer survival is likely to be explained by several methodologic limitations including confounding, reverse causation, and collider stratification bias. Also, the inadequacy of BMI as a measure of body fatness in cancer patients commonly experiencing changes in body weight and body composition may have resulted in the paradox. Other factors contributing to the divergent results in literature are significant heterogeneity in study design and method (e.g., study population, follow-up length); time of BMI assessment (pre-, peri-, or post-diagnosis); and lack of consideration for variability in the strength and directions of associations by age, sex, race/ethnicity, and cancer subtype. Robust but practical methods to accurately assess body fatness and body compositions and weight trajectories in cancer survivors are needed to advance this emerging field and to develop weight guidelines to improve both the length and the quality of cancer survival. Cancer Res; 78(8); 1898-903. ©2018 AACR.

A comparison of perinephric fat surface area and Mayo Adhesive Probability score in predicting malignancy in T1 renal masses

INTRODUCTION

Recent studies have proposed that nearby fat deposits may have metabolic influence on kidney cancer pathobiology. Both fat quantity and quality may play unique roles in this complex relationship. As such, we investigated whether perinephric fat surface area (PFA), a quantitative measure of fat, or Mayo Adhesive Probability (MAP) score, a qualitative measure, were predictive of malignant pathology or Fuhrman grade in small renal masses.

METHODS

A total of 317 patients undergoing minimally invasive partial nephrectomy between 2010 and 2016 for renal masses were retrospectively reviewed. Preoperative abdominal CT and MRI scans were measured for PFA and MAP scores. Multiple binary logistic regression models were created to identify predictive factors of malignant disease and Fuhrman grade.

RESULTS

A total of 253 patients had malignant masses, while 64 had benign masses. A total of 189 of the malignant masses were T1a, while 64 were designated T1b. A total of 221 patients with malignant masses had reported Fuhrman grades. Of these 211 patients, 143 (64.7%) had low-grade and 78 (35.3%) had high-grade disease. Mean PFA was 18.0 ± 13.3 cm², while mean MAP score was 2.6 ± 1.2. Binary logistic regression analysis yielded three variables in the best-fit model for predictors of malignant pathology: MAP score (OR = 1.374, 95% CI: 1.007-1.873, P = 0.045), male sex (OR = 2.058, 95% CI: 1.004-4.218, P = 0.049), and BMI (OR = 1.064, 95% CI: 0.998-1.135, P = 0.059). Neither MAP nor PFA was predictive of Fuhrman grade.

CONCLUSIONS

MAP score, a measure of perinephric fat quality, but not PFA, a qualitative measure of fat quantity, was predictive of malignant pathology, raising the question whether fat quality rather than quantity may be involved in the pathophysiology of RCC in a large and diverse patient population. Understanding the increasing burden of obesity, further studies are needed to elaborate on these findings and to discern the exact relationship between perinephric fat deposits and renal tumorigenesis.

Physical Activity Decreases Kidney Cancer Mortality

BACKGROUND

To investigate associations of kidney cancer mortality with modifiable risk factors of obesity, physical activity, and smoking.

METHODS

We evaluate baseline data from US National Health Information Survey from 1998 through 2004 linked to mortality data reporting deaths through 2006. The primary outcome variable was kidney cancer-specific mortality and primary exposure variables were self-reported physical activity and body mass index (BMI). We utilized multivariable adjusted Cox proportional hazards regression models, with delayed entry to account for age at survey interview.

RESULTS

Among 222,163 individuals with complete follow-up data we identified 71 kidney cancer-specific deaths. In multivariate analyses, individuals who reported "any physical activity" were 50% less likely [adjusted hazard ratio (adjusted HR) 0.50, 95% CI 0.27-0.93, p = 0.028] to die of kidney cancer than non-exercisers, while obese individuals (BMI ≥ 30 kg/m2) were nearly 3 times more likely (adjusted HR 2.84, 95% CI 1.30-6.23, p = 0.009) compared to those of normal weight (BMI < 25 kg/m2). Compared to never smokers, former smokers were twice as likely to die of kidney cancer (adjusted HR 2.00, 95% CI 1.05-3.80, p = 0.034).

CONCLUSION

Physical activity decreases and obesity increases the risk of kidney cancer mortality.

Impact of body mass index on clinicopathological outcomes in patients with renal cell carcinoma without anorexia-cachexia syndrome

Although obesity defined by a high body mass index (BMI) is generally associated with increased risk of renal cell carcinoma (RCC), low BMI has paradoxically been associated with increased tumor aggressiveness and poor prognosis. As anorexia-cachexia syndrome (ACS) is associated with decreased BMI and is frequently observed in patients with advanced RCC, the present study investigated the association of BMI with tumor aggressiveness and prognosis in RCC in relation to ACS. The association of BMI with clinicopathological parameters was analyzed in 503 consecutive patients who underwent surgery for RCC. Kaplan-Meier curves and rates of overall survival (OS) stratified by BMI were also compared in relation to the presence or absence of ACS, defined as the presence of anorexia or malaise, and/or weight loss and/or hypoalbuminemia. Low BMI was significantly associated with high-grade tumors (P=0.0027) and the presence of distant metastasis (P=0.0025), and patients with a lower BMI had significantly shorter OS than those with a higher BMI (P=0.0441). Patients with ACS had a significantly lower BMI (mean, 21.5 kg/m²) than those without ACS (mean, 23.5 kg/m²; P<0.0001) and had significantly shorter OS than those without ACS (P<0.0001). On multivariate analysis, ACS was an independent predictor of short OS [P=0.0089; hazard ratio (HR), 2.21; 95% confidence interval (CI), 1.22–3.92] and short cancer-specific survival (P=0.0308; HR, 2.03; 95% CI, 1.07–3.78); however, BMI was not (P=0.5440 and P=0.6804, respectively). In the 413 patients without ACS at initial presentation, BMI was not associated with any clinicopathological parameters or OS (log-rank, P=0.4591). BMI itself was not a predictor of survival in patients without ACS, and the association between low BMI and increased tumor aggressiveness and poor prognosis could be due to ACS.

Clinical implication of ectopic liver lipid accumulation in renal cell carcinoma patients without visceral obesity

Fatty liver has emerged as a prognostic marker of cancer, so we investigated the impact of ectopic lipid accumulation in liver on the clinical outcome for patients with renal cell carcinoma (RCC). The records of 230 consecutive patients who had undergone surgery for RCC were reviewed, and liver lipid accumulation was estimated from the attenuation in unenhanced preoperative CT images. The median liver CT values of patients with G3 tumors was lower than that of patients with G1-2 tumors (P = 0.0116), that of patients with pT3-4 tumors was lower than that of patients with pT1-2 tumors (P = 0.0336), and that of patients with visceral obesity defined as a visceral fat area ≥ 100 cm² was lower than that of patients without visceral obesity (P < 0.0001). In patients without visceral obesity the median liver CT values of patients with pT3-4 tumors was lower than that of patients with pT1-2 tumors (P = 0.0401), that of patients with metastasis was lower than that of patients without metastasis (P = 0.026), and fatty liver was associated with shorter overall survival (P = 0.0009). Ectopic lipid accumulation in liver thus seems to be a predictor of aggressive forms of RCC.

Renal Cell Carcinoma and Visceral Adipose Index: a new risk parameter

Purpose:

The aim of this study was to evaluate the relationship between tumor size and grade with visceral adipose index (VAI) levels in patients with renal cell carcinoma.

Materials and methods:

We retrospectively reviewed the records of 310 consecutive patients with RCC who underwent radical nephrectomy at our institution between January 2007 and May 2014. VAI was calculates for males and females seperately as this formula like previous study. The relationship between tumor size and nuclear grade with VAI levels were evaluated statisticaly. Analyses were completed using Chi-square tests and Logistic regression analysis.

Results:

Among the 310 total patients analyzed in our study, there were 176 males (56.8%) and 134 females (43.2%). VAI levels were statistically higher in men and women with high tumor size (p<0.001). VAI levels were statistically higher in men and women with high fuhrman grade (p<0.001).

Conclusions:

The components of VAI may have effect on tumor carcinogenesis in similar pathways. In our study patients with high VAI levels were found to have statistically significant higher nuclear grade and tumor size. VAI can be a useful index for the evaluation and calculation of renal cell cancer aggressiviness. Further studies with more patients are needed to confirm our study.

Long-Term Body Mass Index Trends After Living-Donor Nephrectomy

OBJECTIVES

As the demand for kidney transplant allografts has increased, many centers are expanding the upper limit of acceptable body mass index for kidney donors. However, obesity is a risk factor for developing renal disease. Our goal was to quantify body mass index trends in donor nephrectomy patients and to institute nutrition counseling to promote sustainable weight loss to reduce the risk of metabolic syndrome-derived renal dysfunction.

MATERIALS AND METHODS

Ninety patients who underwent donor nephrectomy between 2007 and 2012 consented to having height and weight data collected at multiple time points. After data collection, each patient underwent a standardized nutrition counseling session. One year later, body mass index was reassessed.

RESULTS

Preoperatively, 52% of the patients were overweight or obese. The percentage of overweight and obese patients remained stable for 2 years after surgery. However, at 3, 4, and 5 years after surgery, these rates increased to 59%, 69%, and 91%. Each patient was counseled about obesity-related comorbidities and provided information about lifestyle modification. One year later, 94% of previously overweight patients and 82% of previously obese patients had a decrease in mean body mass index from 27.2 ± 4.0 kg/m2 to 25.1 ± 3.6 kg/m2.

CONCLUSIONS

Living-donor nephrectomy patients are at risk of developing obesity, similar to the adult population. Nutrition counseling may be beneficial to help normalize body mass index in patients who have become overweight or obese to potentially prevent obesity-related comorbidities. All patients were evaluated by a nutrition specialist after surgery to review our donor nephrectomy nutrition brochure. Body mass index monitoring and primary care follow-up appear to be appropriate surveillance methods.

Renal cell carcinoma: links and risks

This review provides an overview of the incidence of renal cell carcinoma (RCC) and a summary of the most commonly associated risk factors. A literature review was performed with a focus on recent studies with a high level of evidence (large prospective cohort studies and meta-analyses). The incidence rate of RCC varies globally, with the rate rising rapidly in more developed regions, demonstrating the effects of increased use of diagnostic imaging and prevalence of modifiable risk factors. Based on the current evidence, cigarette smoking, obesity, and hypertension are the most well-established risk factors for sporadic RCC worldwide. Acquired cystic kidney disease is also a significant risk factor, specifically in dialysis patients. There is increasing evidence for an inverse association between RCC risk and moderate alcohol consumption. Certain analgesics and occupational exposure have been linked to an increased risk of RCC, although data are limited. Diets rich in fruits and vegetables may provide a protective effect.

Obesity and Kidney Cancer

Renal cell cancer (RCC) is the major type of kidney cancer with increasing incidence. Obesity is one of the well-established risk factors for RCC. Meta-analyses including multiple cohort and case-control studies have found a consistent positive association between obesity and RCC. The association appeared to be independent of other RCC risk factors including hypertension and has been often stronger in women, although a positive association has also been observed in men. Obesity has been largely measured as body mass index (BMI). Studies which evaluated other measures of obesity including waist circumference (WC), waist-to-hip ratio (WHR) as well as increase in weight have reported similar positive associations with RCC. Although the mechanisms by which obesity influences renal carcinogenesis have been under-explored, insulin resistance and certain growth factors including insulin-like growth factor (IGF-1), sex steroid hormones, and biochemical markers such as adiponectin may be involved. The positive association with obesity has been observed with the clear cell type of RCC, which is the major histological subtype. On the other hand, the association between obesity and RCC survival appears to be much more complex. An apparent inverse association between obesity at time of diagnosis and RCC survival has been observed in some studies' generating speculation of an "obesity paradox" hypothesis. However, this "paradox" may be due to reverse causation, selection bias, or other forms of bias rather than a true biological association.

Extreme obesity does not predict poor cancer outcomes after surgery for renal cell cancer

OBJECTIVE

To assess whether extreme obesity (body mass index [BMI] ≥ 40 kg/m(2) ) is associated with peri-operative outcomes, overall survival (OS), cancer-specific survival (CSS), or recurrence-free survival (RFS) after surgical treatment for renal cell carcinoma (RCC).

PATIENTS AND METHODS

After institutional review board approval, we used an institutional database to identify patients treated surgically between January 2000 and December 2014 with a pathological diagnosis of RCC. Comprehensive clinical and pathological data were reviewed. Kaplan-Meier analyses were used to estimate OS, RFS and CSS. Univariate and multivariate Cox proportional hazards analysis was used to evaluate associations with OS, CSS and RFS in patients with extreme obesity, among other known predictive variables.

RESULTS

In all, 100 patients (11.9%) with a BMI ≥ 40 kg/m(2) and 743 patients (88.1%) with a BMI < 40 kg/m(2) who were treated surgically for RCC were identified. Morbid obesity was not associated with an increased risk of blood transfusion (odds ratio [OR] 1, 95% confidence interval [CI] 0.587-1.70; P = 1.0). The median (interquartile range) length of hospital stay (LOS) was 4 (3-6) days. Morbid obesity was not associated with longer LOS (P = 0.26) or 30-day hospital readmission rates (P = 1.0). Major complications (Clavien ≥ 3a) were recorded in 67 patients (7.95%). BMI ≥ 40 kg/m(2) was not a predictor of major complications (OR 0.58, 95% CI 0.227-1.47; P = 0.251) or 90-day mortality (P = 0.4067). BMI ≥ 40 kg/m(2) was not associated with worse OS (P = 0.7), CSS (P = 0.2) or RFS (P = 0.5). BMI ≥ 35 kg/m(2) was also not associated with worse OS, CSS or RFS (P = 0.3, 0.1, 0.5, respectively). The 5-year OS rate was 68.9% for the entire cohort, including 69 and 70% for patients with BMI < 40 kg/m(2) and BMI ≥ 40 kg/m(2) , respectively (P = 0.69). The 5-year CSS was 79.5% for the entire cohort, including 78.4 and 87.9% (P = 0.16) for patients with BMI < 40 kg/m(2) and BMI ≥ 40 kg/m(2) , respectively. The 5-year RFS rates for BMI < 40 kg/m(2) and BMI ≥ 40 kg/m(2) were 84.1 and 90.6%, respectively (P = 0.48).

CONCLUSIONS

Extreme obesity is not associated with worse peri-operative or cancer outcomes after surgery for RCC. Surgery should remain a standard treatment option in well selected morbidly obese patients.

Imaging methods for analyzing body composition in human obesity and cardiometabolic disease

Advances in the technological qualities of imaging modalities for assessing human body composition have been stimulated by accumulating evidence that individual components of body composition have significant influences on chronic disease onset, disease progression, treatment response, and health outcomes. Importantly, imaging modalities have provided a systematic method for differentiating phenotypes of body composition that diverge from what is considered normal, that is, having low bone mass (osteopenia/osteoporosis), low muscle mass (sarcopenia), high fat mass (obesity), or high fat with low muscle mass (sarcopenic obesity). Moreover, advances over the past three decades in the sensitivity and quality of imaging not just to discern the amount and distribution of adipose and lean tissue but also to differentiate layers or depots within tissues and cells is enhancing our understanding of distinct mechanistic, metabolic, and functional roles of body composition within human phenotypes. In this review, we focus on advances in imaging technologies that show great promise for future investigation of human body composition and how they are being used to address the pandemic of obesity, metabolic syndrome, and diabetes.

The Impact of Diabetes Mellitus on Renal Cell Carcinoma Prognosis: A Meta-Analysis of Cohort Studies

Previous studies that investigated the relationship between DM and survival in renal cell carcinoma (RCC) patients reported inconsistent findings. Hence, we conducted a meta-analysis to obtain a more precise evaluation of the prognostic significance of DM in RCC. A systematic review was conducted with PubMed, Embase, and Web of Science to identify relevant articles that evaluated the effect of DM on RCC patients. Based on the inclusion and quality assessment criteria, 18 studies were eligible for the meta-analysis. Pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI) for overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) were calculated by standard meta-analysis techniques. The results suggested that DM was associated with poor OS (HR 1.56, 95% CI, 1.35-1.81, P < 0.001), poor CSS (HR 2.03, 95% CI, 1.37-3.01, P < 0.001), and poor RFS (HR 1.73, 95% CI, 1.25-2.39, P = 0.012). In addition, for patients with localized RCC, patients with clear cell RCC, or patients receiving nephrectomy, DM was associated with both poor OS and CSS by subgroup analyses. Our study revealed that there was a significant negative impact of DM on OS, CSS, and RFS in RCC patients. Therefore, more attention should be paid to RCC patients with preexisting DM because of their poor prognosis.