The Association Between Body Mass Index and the Prognosis and Postoperative Complications of Hepatocellular Carcinoma: A Meta-Analysis

Metabolic dysfunction-associated fatty liver disease increases the risk of complications after radical resection in patients with hepatocellular carcinoma

BACKGROUND AND AIMS

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) in hepatocellular carcinoma (HCC) patients is increasing, yet its association with postoperative complications of HCC remains unclear. The aim of this study was to investigate the impact of MAFLD on complications after radical resection in HCC patients.

METHODS

Patients with HCC who underwent radical resection were included. Patients were stratified into MAFLD group and non-MAFLD group. Clinical features and post-hepatectomy complications were compared between the two groups, and logistic regression analysis was used to determine independent risk factors associated with post-hepatectomy complications.

RESULTS

Among the 936 eligible patients with HCC who underwent radical resection, concurrent MAFLD was diagnosed in 201 (21.5%) patients. Compared to the non-MAFLD group, the MAFLD group exhibited a higher incidence of complications, including infectious and major complications after radical resection in HCC patients. The logistic regression analysis found that MAFLD was an independent risk factor for complications, including infectious and major complications in HCC patients following radical resection (OR 1.565, 95%CI 1.109-2.343, P = 0.012; OR 2.092, 95%CI 1.386-3.156, P < 0.001; OR 1.859, 95% CI 1.106-3.124, P = 0.019; respectively). Subgroup analysis of HBV-related HCC patients yielded similar findings, and MAFLD patients with type 2 diabetes mellitus (T2DM) exhibited a higher incidence of postoperative complications compared to those without T2DM (all P < 0.05).

CONCLUSIONS

Concurrent MAFLD was associated with an increased incidence of complications after radical resection in patients with HCC, especially MAFLD with T2DM.

Cancer risk and survival according to body mass index in hepatobiliary malignancies: a nationwide registry-based cohort study

BACKGROUND

The aim of this study was to explore the associations between BMI and cancer of the liver, bile ducts, and gallbladder.

METHODS

A registry-based cohort study was performed by linking data from several national registries in Norway.

RESULTS

The cohort comprised 1 723 692 individuals including 4768 hepatobiliary cancer cases during 55 743 509 person-years of follow-up. In men, we found increased risk of cancer per 5 kg/m2 BMI increase for hepatocellular carcinoma and extrahepatic cholangiocarcinoma. In women there was increased risk of extrahepatic cholangiocarcinoma and gallbladder cancer. Women with high BMI in early adulthood had increased risk of intrahepatic cholangiocarcinoma. Reduced cancer-specific survival was found for all hepatobiliary malignancies in women with overweight and obesity. In men, reduced survival was observed in individuals with obesity for all hepatobiliary cancers, except gallbladder cancer. Increased risk of cancer-death per 5 kg/m2 BMI increase was found for hepatocellular carcinoma, intra-, and extrahepatic cholangiocarcinoma in women. For men, 5 kg/m2 BMI increase was positively associated with cancer-death from intrahepatic cholangiocarcinoma.

DISCUSSION

This study supports the notion of an increased risk of hepatobiliary cancers with increasing BMI, with sex and age variations. The findings also suggest a higher risk of cancer-death with increasing BMI.

A Review of Incidence and Related Risk Factors in the Development of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy, ranking as the seventh most common cancer globally and the second leading cause of deaths due to cancer. This review examines the incidence of HCC, its associated risk factors, and constantly changing global trends. Incidence has been noted to be varying worldwide, particularly due to environmental and infectious risk factors. Chronic hepatitis B (HBV) and C (HCV) virus infections, alcohol abuse, aflatoxin exposure, diabetes, obesity, and tobacco consumption are some of the leading risk factors noted. Eastern Asia and sub-Saharan Africa were noted to have the highest disease burden for HCC, with China representing a considerably large majority. On the contrary, the United States reports a lower HCC incidence overall due to improved vaccination programs against HBV; however, with a rising incidence of prominent risk factor in non-alcoholic fatty liver disease (NAFLD), the trend may very well change. Gender disparities were noted to be evident with men experiencing higher rates of HCC compared to women, which may be due to various environmental and biological factors, including alcohol intake, smoking, and androgen hormone levels. Currently, efforts to reduce the overall incidence of HCC include universal HBV vaccinations, antiviral therapies, aflatoxin prevention measures, genetic screening for hereditary hemochromatosis, and early ultrasound evaluation in patients with liver cirrhosis. Understanding these evolving trends and risk factors is essential in combating the rising HCC incidence, especially in Western countries, where risk factors, such as obesity, diabetes, and metabolic disorders, are on the rise.

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.

Operative and long-term oncologic outcomes of laparoscopic versus open major liver resection in patients with a high body mass index (> 25 kg/m2): a propensity score matching analysis

BACKGROUND

With the recent rapid increase in the prevalence of obesity, the number of obese patients requiring liver resection, including laparoscopy, has increased. Accordingly, evaluating the outcome of laparoscopic liver resection in obese patients is increasingly important. This study aimed to compare the safety and feasibility of laparoscopic major liver resection (LMR) and open major liver resection (OMR) in patients with a high body mass index (BMI > 25.0 kg/m²).

METHODS

We reviewed 521 patients with high BMI (> 25.0 kg/m²) who underwent major liver resection for various indications between January 2009 and November 2018 at Asan Medical Center. We performed 1:1 propensity score matching of the LMR and OMR groups, with 120 patients subsequently included in each group.

RESULTS

LMR was associated with lower blood loss and shorter postoperative hospital stays (p < 0.001). Although there was no significant difference in overall complications (p = 0.080), non-liver-specific complications were observed less frequently after LMR (p = 0.025). American Society of Anesthesiologists class > II, BMI > 30 kg/m², and malignancy were independent predictors of morbidity. In a subgroup analysis of patients with hepatocellular carcinoma, there was no significant difference between the two groups in overall survival (hazard ratio 0.225; 95% confidence interval 0.049-1.047; p = 0.057) and recurrence-free survival (hazard ratio 0.761; 95% confidence interval 0.394-1.417; p = 0.417).

CONCLUSIONS

Obesity should not be considered a contraindication for major liver resection using a laparoscopic approach; however, when applying this approach for resecting malignancies in patients with a BMI > 30 kg/m² and comorbid diseases, special attention should be paid to the possibility of complications.

Impact of Metabolic Syndrome on Postoperative Outcomes Among Medicare Beneficiaries Undergoing Hepatectomy

INTRODUCTION

The impact of metabolic syndrome (MetS) on postoperative outcomes following liver surgery is not well studied. The objective of the current study was to examine the association of MetS with individual perioperative outcomes, as well as the composite "textbook outcome" (TO) following liver resection for both benign and malignant indications.

METHODS

The Medicare 100% Standard Analytic Files were reviewed to identify Medicare beneficiaries who underwent hepatectomy between 2013 and 2017. The impact of MetS on complications, length of stay (LOS), 90-day readmission, 90-day mortality, and TO following hepatectomy was investigated.

RESULTS

Among 13,898 patients who underwent hepatectomy, 2491 (17.9%) had MetS while 11,407 (82.1%) did not. Patients with MetS were more often male (59.1% vs 48.5%), Black (8.5% vs 6.6%), and had a diagnosis of cancer (69.9% vs 65.1%) (all p<0.001). On multivariable analysis, patients with MetS had higher odds of complications (OR 1.41, 95% CI 1.28-1.55), 90-day readmission (OR 1.27, 95% CI 1.15-1.40), and 90-day mortality (OR 1.32, 95% CI 1.13-1.54). In turn, patients with MetS had markedly lower odds of TO following hepatectomy compared with non-MetS patients (OR=0.76, 95% CI 0.70-0.83). Of note, patients with MetS had lower odds of TO after both minimally invasive (OR=0.59, 95% CI 0.43-0.81) and open (OR=0.75, 95% CI 0.68-0.82) liver surgery. Individuals with MetS also had a higher overall expenditure during the index hospitalization compared with non-MetS patients ($19.9k USD vs. $18.8k USD, p<0.001).

CONCLUSION

Patients with MetS had increased morbidity and mortality, as well as lower likelihood to achieve a TO following liver resection. MetS increased the operative risk and overall Medicare expenditures associated with hepatic resection.

Influence of diabetes on short-term outcome after major hepatectomy: an underestimated risk?

BACKGROUND

Patient-related risk factors such as diabetes mellitus and obesity are increasing in western countries. At the same time the indications for liver resection in both benign and malignant diseases have been significantly extended in recent years. Major liver resection is performed more frequently in a patient population of old age, comorbidity and high rates of neoadjuvant chemotherapy. The aim of this study was to evaluate whether diabetes mellitus, obesity and overweight are risk factors for the short-term post-operative outcome after major liver resection.

METHODS

Four hundred seventeen major liver resections (≥ 3 segments) were selected from a prospective database. Exclusion criteria were prior liver resection in patient's history and synchronous major intra-abdominal procedures. Overweight was defined as BMI ≥ 25 kg/m2 and < 30 kg/m2 and obesity as BMI ≥ 30 kg/m2. Primary end point was 90-day mortality and logistic regression was used for multivariate analysis. Secondary end points included morbidity, complications according to Clavien-Dindo classification, unplanned readmission, bile leakage, and liver failure. Morbidity was defined as occurrence of a post-operative complication during hospital stay or within 90 days postoperatively.

RESULTS

Fifty-nine patients had diabetes mellitus (14.1%), 48 were obese (11.6%) and 147 were overweight (35.5%). There were no statistically significant differences in mortality rates between the groups. In the multivariate analysis, diabetes was an independent predictor of morbidity (OR = 2.44, p = 0.02), Clavien-Dindo grade IV complications (OR = 3.6, p = 0.004), unplanned readmission (OR = 2.44, p = 0.04) and bile leakage (OR = 2.06, p = 0.046). Obese and overweight patients did not have an impaired post-operative outcome compared patients with normal weight.

CONCLUSIONS

Diabetes has direct influence on the short-term postoperative outcome with an increased risk of morbidity but not mortality. Preoperative identification of high-risk patients will potentially decrease complication rates and allow for individual patient counseling as part of a shared decision-making process. For obese and overweight patients, major liver resection is a safe procedure.

Effect of Nonalcoholic Fatty Liver Disease and Metabolic Risk Factors on Waitlist Outcomes in Patients With Hepatocellular Carcinoma

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of hepatocellular carcinoma (HCC) in the United States. Prior data suggest that NAFLD-HCC patients are less likely to receive liver transplantation (LT) and have worse overall survival; however, the reason for this discrepancy is unknown.

Obesity and liver cancer

Obesity prevalence is rapidly increasing worldwide. It is associated with huge economic and health costs due to its clinical consequences, which includes increased incidence of type 2 diabetes, cardiovascular diseases, and development of different malignancies. In particular, obesity is an independent risk factor for the development of hepatocellular carcinoma (HCC). Indeed, obesity is highly prevalent in patients with non-alcoholic fatty liver disease (NAFLD) that is becoming one of the most frequent causes of liver disease worldwide. NAFLD-related HCC is the most rapidly growing indication for liver transplantation in many countries. The higher mortality rates found in obese HCC patients might be related not only to a worse outcome after HCC treatments, but also to a delayed diagnosis related to a low frequency and a poorer quality of abdominal ultrasonography surveillance that is the test universally used for HCC screening. Given its diffusion, obesity is frequently present in patients with chronic liver diseases related to different etiologies, and in these cases it may increase the HCC risk, acting as an additional co-factor. Indeed, growing evidence demonstrates that a healthy diet and regular physical activity may have an impact in reducing the overall HCC risk. Finally, an impact of obesity in the development of intrahepatic cholangiocarcinoma has been postulated, but more extensive studies are needed to definitively confirm this association.

Overweight and Obesity as Independent Factors for Increased Risk of Hepatocellular Cancer-Related Mortality: A Meta-Analysis

Obesity is related to the amplified risk of developing hepatocellular cancer, but its outcome on hepatocellular cancer-related mortality remains uncertain. Hence, the present study aimed to perform a meta-analysis study to evaluate the relationship between weight and hepatocellular cancer-related deaths. Through a systematic literature search up to December 2019, 7 observational studies with 2,349,834 subjects, 4834 hepatocellular cancer-related deaths were identified reporting relationships between body mass index (BMI), and hepatocellular cancer-related mortality. Odd ratio (OR) with 95% confidence intervals (CIs) was calculated comparing obese, BML > 30kg/m², and overweight, BMI, 25-29.9 kg/m² to subjects with normal BMI using the dichotomous method with a random-effect model. In obese subjects, males (OR, 1.84; 95% CI, 1.25-2.70) and females (OR, 1.26; 95% CI, 1.11-1.44), had higher hepatocellular cancer-related mortality compared to normal BMI subjects. However, overweight males (OR, 1.12; 95% CI, 0.98-1.28) and overweight females (OR, 1.06; 95% CI, 0.95-1.18), did not have such risk with moderate heterogeneity. The extent of increased mortality was higher in obese males compared to obese females. The impact of obesity on hepatocellular cancer-related mortality was observed in all populations with less extant in the black population. Based on this meta-analysis, obesity may have an independent relationship with up to the 1.84-fold risk of hepatocellular cancer-related mortality. This relationship was more pronounced in males than in females. Key teaching pointsBeing overweight is related to the amplified risk of developing hepatocellular cancer.Obesity's affect on hepatocellular cancer-related mortality remains uncertain.Based on this meta-analysis, obesity may have an independent relationship with up to the 1.84-fold risk of hepatocellular cancer-related mortality.This relationship was more pronounced in males than in females.

Impact of overweightness and critical weight loss on overall survival in patients with hepatocellular carcinoma initially treated with chemoembolization

BACKGROUND

The effects of overweightness and weight loss on the development and prognosis of hepatocellular carcinoma (HCC) remain unclear. In this study, we aimed to evaluate the impact of overweightness and weight loss on the survival of patients with intermediate/advanced HCC receiving chemoembolization as initial treatment.

METHODS

We examined 1,170 patients who underwent chemoembolization as initial treatment for Barcelona-Clínic Liver Cancer stages B and C HCC at Sun Yat-sen University Cancer Center (Guangzhou, China) between December 2009 and May 2015. A baseline body mass index (BMI) of ≥23 kg/m² was defined as overweight, and body-weight loss of ≥5.0% from baseline was defined as critical weight loss (CWL). Cox regression analysis was used to determine the association between overweightness or CWL and overall survival (OS).

RESULTS

The median survival time was 16.8 (95% confidence interval, 13.9-19.7) months and 11.1 (95% confidence interval, 10.0-12.2) months in the overweight and non-overweight groups (log-rank test, P < 0.001), respectively. Cox multivariate analysis identified overweightness as an independent protective prognostic factor for OS (P < 0.001). Subgroup stratification analysis revealed a significant association between overweightness and survival among patients receiving further treatment (P = 0.005), but not in those not receiving further treatment (P = 0.683). Multivariate analysis showed that both overweightness and CWL were independent prognostic factors for OS among patients receiving further treatment.

CONCLUSION

Among patients with intermediate- or advanced-stage HCC initially treated with chemoembolization, overweightness was associated with longer OS. Furthermore, CWL was an independent adverse prognostic factor for OS in patients receiving additional treatment.

Metabolic syndrome and hepatic surgery

In Europe, the prevalence of metabolic syndrome (MS) has reached the endemic rate of 25%. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of MS. Its definition is histological, bringing together the different lesions associated with hepatic steatosis (fat deposits on more than 5% of hepatocytes) without alcohol consumption and following exclusion of other causes. MS and NAFLD are implicated in the carcinogenesis of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). At present, HCC and ICC involving MS represent 15-20% and 20-30% respectively of indications for hepatic resection in HCC and ICC. Moreover, in the industrialized nations NAFLD is tending to become the most frequent indication for liver transplantation. MS patients combine the operative risk associated with their general condition and comorbidities and the risk associated with the presence and/or severity of NAFLD. Following hepatic resection in cases of HCC and ICC complicating MS, the morbidity rate ranges from 20 to 30%, and due to cardiovascular and infectious complications, post-transplantation mortality is heightened. The operative risk incurred by MS patients necessitates appropriate management including: (i) precise characterization of the subjacent liver; (ii) an accurately targeted approach privileging detection and optimization of treatment taking into account the relevant cardiovascular risk factors; (iii) a surgical strategy adapted to the histology of the underlying liver, with optimization of the volume of the remaining (postoperative) liver.

Influence of obesity on in-hospital and postoperative outcomes of hepatic resection for malignancy: a 10-year retrospective analysis from the US National Inpatient Sample

OBJECTIVES

The influence of obesity on the outcomes of curative liver resection for malignancies remains controversial. We aimed to compare the in-hospital outcomes of liver resection for malignancy between obese and non-obese patients.

DESIGN

This was a population-based, retrospective, observational study using data from the Nationwide Inpatient Sample (NIS), the largest all-payer US inpatient care database.

SETTING

Hospitalisations of adults ≥18 years old with diagnoses of primary hepatobiliary malignancy or secondary malignant neoplasms of liver in the USA were identified from the NIS database between 2005 and 2014.

PARTICIPANTS

Data of 18 398 patients ≥18 years old and underwent liver resection without pancreatic resection in the NIS were extracted. All included subjects had primary hepatobiliary malignancy or secondary malignant neoplasms of the liver. Patients were divided into obese and non-obese groups. These groups were compared with respect to postoperative complications, length of hospital stay and hospital cost according to surgical extent and approach.

INTERVENTIONS

Patients were undergoing lobectomy of liver or partial hepatectomy.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoints of this study were postoperative complications, length of hospital stay and hospital cost.

RESULTS

After adjustment, obese patients were significantly more likely to experience postoperative complications than were non-obese patients (adjusted OR 1.25, 95% CI 1.10 to 1.42), regardless of whether lobectomy or partial hepatectomy was performed. Furthermore, obesity was significantly associated with increased risk of postoperative complications in patients who underwent open liver resection, but not laparoscopic resection. No significant difference was observed in length of hospital stay or total hospital costs between obese and non-obese patients.

CONCLUSIONS

After adjustment for preoperative comorbidities and other potential confounders, obesity is significantly associated with greater risk of complications in patients undergoing open liver resection for malignancy, but not laparoscopic resection.

Obesity is Independently Associated With Increased Risk of Hepatocellular Cancer-related Mortality: A Systematic Review and Meta-Analysis

OBJECTIVE

Excess body weight is associated with increased risk of developing hepatocellular cancer (HCC), but its effect on HCC-related mortality remains unclear. We performed a systematic review and meta-analysis to assess the association between premorbid obesity and HCC-related mortality.

MATERIALS AND METHODS

Through a systematic literature search-up to March 2016, we identified 9 observational studies (1,599,453 individuals, 5705 HCC-related deaths) reporting the association between premorbid body mass index (BMI), and HCC-related mortality. We estimated summary adjusted hazard ratio (aHR) with 95% confidence intervals (CIs), comparing obese (BMI>30 kg/m(2)) and overweight (BMI, 25 to 29.9 kg/m(2)) individuals with normal BMI individuals using random-effects model.

RESULTS

On meta-analysis, compared with individuals with normal BMI, obese (aHR, 1.95; 95% CI, 1.46-2.46), but not overweight individuals (aHR, 1.08; 95% CI, 0.97-1.21), had higher HCC-related mortality, with moderate heterogeneity. On subgroup analysis, magnitude of increased mortality was higher in obese men (aHR, 2.50; 95% CI, 2.02-3.09; 3 studies) as compared with obese women (aHR, 1.45; 95% CI, 1.08-1.97; 2 studies). The impact of premorbid obesity on HCC-related mortality was observed only in western populations (aHR, 2.10; 95% CI, 1.77-2.48; 4 studies), but not Asian populations (aHR, 1.10; 95% CI, 0.63-1.92; 1 study). There was limited assessment of competing risk because of advanced liver disease.

CONCLUSIONS

On the basis of this meta-analysis, premorbid obesity may be independently associated with a 2-fold risk of HCC-related mortality. This association was more pronounced in men and western populations. Strategies targeting obesity-associated metabolic abnormalities may provide novel pathways for HCC therapy.

Multicentre study of the prognostic impact of preoperative bodyweight on long-term prognosis of hepatocellular carcinoma

BACKGROUND

Whether preoperative bodyweight is associated with long-term prognosis in patients after liver resection for hepatocellular carcinoma (HCC) is controversial. This study aimed to investigate the relationship of patient weight with long-term recurrence and overall survival (OS) after curative liver resection for HCC.

METHODS

Data for patients with HCC who underwent curative liver resection between 2000 and 2015 in five centres in China were analysed retrospectively in three groups according to their preoperative BMI: underweight (BMI 18·4 kg/m² or less), normal weight (BMI 18·5-24·9 kg/m² ) and overweight (BMI 25·0 kg/m² or above). Patients' baseline characteristics, operative variables and long-term survival outcomes were compared. Univariable and multivariable Cox regression analyses were performed to identify risk factors for OS and recurrence-free survival (RFS) after resection.

RESULTS

Of 1524 patients, 107 (7·0 per cent) were underweight, 891 (58·5 per cent) were of normal weight and 526 (34·5 per cent) were overweight. Univariable analyses showed that underweight and overweight patients had poorer OS (both P < 0·001) and RFS (both P < 0·001) than patients of normal weight. Multivariable Cox regression analysis also identified both underweight and overweight to be independent risk factors for OS (hazard ratio (HR) 1·22, 95 per cent c.i. 1·19 to 1·56, P = 0·019; and HR 1·57, 1·36 to 1·81, P < 0·001, respectively) and RFS (HR 1·28, 1·16 to 1·53, P = 0·028; and HR 1·34, 1·17 to 1·54, P < 0·001).

CONCLUSION

Underweight and overweight patients appear to have a worse prognosis than those of normal weight following liver resection for HCC.

Are Metabolic Signatures Mediating the Relationship between Lifestyle Factors and Hepatocellular Carcinoma Risk? Results from a Nested Case-Control Study in EPIC

Background: The "meeting-in-the-middle" (MITM) is a principle to identify exposure biomarkers that are also predictors of disease. The MITM statistical framework was applied in a nested case-control study of hepatocellular carcinoma (HCC) within European Prospective Investigation into Cancer and Nutrition (EPIC), where healthy lifestyle index (HLI) variables were related to targeted serum metabolites.Methods: Lifestyle and targeted metabolomic data were available from 147 incident HCC cases and 147 matched controls. Partial least squares analysis related 7 lifestyle variables from a modified HLI to a set of 132 serum-measured metabolites and a liver function score. Mediation analysis evaluated whether metabolic profiles mediated the relationship between each lifestyle exposure and HCC risk.Results: Exposure-related metabolic signatures were identified. Particularly, the body mass index (BMI)-associated metabolic component was positively related to glutamic acid, tyrosine, PC aaC38:3, and liver function score and negatively to lysoPC aC17:0 and aC18:2. The lifetime alcohol-specific signature had negative loadings on sphingomyelins (SM C16:1, C18:1, SM(OH) C14:1, C16:1 and C22:2). Both exposures were associated with increased HCC with total effects (TE) = 1.23 (95% confidence interval = 0.93-1.62) and 1.40 (1.14-1.72), respectively, for BMI and alcohol consumption. Both metabolic signatures mediated the association between BMI and lifetime alcohol consumption and HCC with natural indirect effects, respectively, equal to 1.56 (1.24-1.96) and 1.09 (1.03-1.15), accounting for a proportion mediated of 100% and 24%.Conclusions: In a refined MITM framework, relevant metabolic signatures were identified as mediators in the relationship between lifestyle exposures and HCC risk.Impact: The understanding of the biological basis for the relationship between modifiable exposures and cancer would pave avenues for clinical and public health interventions on metabolic mediators. Cancer Epidemiol Biomarkers Prev; 27(5); 531-40. ©2018 AACR.

Revisiting donor risk over two decades of single-center experience: More attention on the impact of overweight

OBJECTIVE

Morbidity rates after living donor hepatectomy vary greatly among centers. Donor morbidity in a tertiary center over the past two decades was revisited.

METHODS

Clinical data and grading of complications were reviewed by a nontransplant surgeon based on Clavien 5 tier grading. Risk factors were analyzed.

RESULTS

In total, 473 consecutive living liver donors from 1997 to 2016 were included for analysis; 305 were right liver donors and 168 left liver donors, and the corresponding morbidity rates were 27.2% and 9.5%. The majority (81/99, 81.2%) of complications were grade I and II. Donors with morbidity compared with those without were significantly younger, nonoverweight body figure (BMI < 25), more as the right liver donors, and longer length of hospital stay. Right liver donation had significantly higher morbidity rates than did left liver donation in earlier periods (before 2011), but not thereafter. Multivariate modeling revealed that right lobe donation and overweight (BMI ≥ 25 kg/m²) were significant factors associated with donor morbidity, with adjusted hazard ratios HR (95% confidence interval) of 3.401 (1.909-6.060) and 0.550 (0.304-0.996), respectively. Further, overweight was a paradoxical risk factor in right donor hepatectomy with HR 0.422 (0.209-0.851), but the effect was nonsignificant in left liver donors. Most complications in overweight donors were grade I and not specific to liver surgery.

CONCLUSIONS

The overall complication rate was 20.9%. Overweight might be protective against morbidity in right hepatectomy and warrants further deliberation.

Obesity and Liver Cancer

Obesity and related metabolic disorders have become globally prevalent posing a challenge for the chronically damaged liver and predisposing the development and progression of cancer. The rising phenomenon of "obesity epidemic" may provide means for understanding why liver cancer is one of the few malignancies with rising incidence in developed countries over the last decades. Non-alcoholic fatty liver disease associated with obesity, insulin resistance, and type 2 diabetes is an increasingly recognized trigger for liver cancer in Western populations characterized by low prevalence of established risk factors for liver cancer such as viral hepatitis and hepatotoxin exposure. Accumulating evidence has established an association between higher body mass index as an indicator of general obesity and higher risk of primary liver cancer. The associations are stronger in men, in patients with underlying liver disease and in white ethnic groups. Abdominal obesity, weight gain in adult life and metabolic factors related to visceral fat accumulation were also suggested as important risk factors for liver cancer; however, more studies are needed to evaluate these associations. The association of obesity and metabolic parameters with liver cancer survival remains controversial. It is unclear which exact mechanisms could provide links between obesity and liver cancer risk. Recent evidence has implicated several molecular pathways in obesity-associated liver cancer. These include insulin resistance leading to increased levels of insulin and insulin-like growth factors, chronic inflammation, adipose tissue remodeling, pro-inflammatory cytokine and adipokine secretion, and altered gut microbiota. These mechanisms coincide with inflammatory and metabolic processes occurring in non-alcoholic fatty liver disease predisposing cancer development and progression. In the context of the current evidence, better understanding of the role of obesity and related metabolic factors may help in improving current strategies for liver cancer prevention.