Clinical study on the correlation between metabolic syndrome and colorectal carcinoma

Systematic review and meta-analysis: Associations between metabolic syndrome and colorectal neoplasia outcomes

AIM

Metabolic syndrome (MetS) is a cluster of factors including obesity, hypertension, diabetes, hypercholesterolemia and hyperlipidaemia. It has been associated with an increased risk of colorectal neoplasia. This systematic review and meta-analysis assessed the association between MetS and (i) recurrence of adenomas or occurrence of CRC in patients with prior adenomas, and (ii) survival in patients with CRC.

METHOD

MEDLINE, Embase, Scopus and Web of Science were searched up to 22 November 2019. Two authors independently conducted title and abstract screening; full text of eligible studies was evaluated. Where ≥3 studies reported effect measures for a specific outcome, meta-analysis using random effects model was conducted. I² was used to assess between-study heterogeneity. Quality appraisal was undertaken with the Newcastle-Ottawa Score.

RESULTS

The search identified 1,764 articles, 55 underwent full text screening, resulting in a total of 15 eligible studies. Five studies reported on metachronous neoplasia, with differing outcomes precluded a meta-analysis. No consistent relationship between MetS and metachronous neoplasia was found. Ten studies reported on survival outcomes. MetS was associated with poorer CRC-specific survival (HR = 1.8, 95% CI: 1.04-3.12, I²  = 92.7%, n = 3). Progression-free survival was also worse but this did not reach statistical significance (HR = 1.12, 95% CI: 0.89-1.42, I²  = 85.6%, n = 3). There was no association with overall survival (HR = 1.04, 95% CI: 0.94-1.15, I²  = 43.7%, n = 7). Significant heterogeneity was present but subgroup analysis did not account for this.

CONCLUSION

MetS is associated with poorer CRC-specific survival, but evidence is inconsistent on metachronous neoplasia. Further research is warranted to better understand the impact of MetS on the adenoma-carcinoma pathway.

Insulin resistance and body composition in cancer patients

Cancer cachexia, weight loss with altered body composition, is a multifactorial syndrome propagated by symptoms that impair caloric intake, tumor byproducts, chronic inflammation, altered metabolism, and hormonal abnormalities. Cachexia is associated with reduced performance status, decreased tolerance to chemotherapy, and increased mortality in cancer patients. Insulin resistance as a consequence of tumor byproducts, chronic inflammation, and endocrine dysfunction has been associated with weight loss in cancer patients. Insulin resistance in cancer patients is characterized by increased hepatic glucose production and gluconeogenesis, and unlike type 2 diabetes, normal fasting glucose with high, normal or low levels of insulin. Cancer cachexia results in altered body composition with the loss of lean muscle mass with or without the loss of adipose tissue. Alteration in visceral adiposity, accumulation of intramuscular adipose tissue, and secretion of adipocytokines from adipose cells may play a role in promoting the metabolic derangements associated with cachexia including a proinflammatory environment and insulin resistance. Increased production of ghrelin, testosterone deficiency, and low vitamin D levels may also contribute to altered metabolism of glucose. Cancer cachexia cannot be easily reversed by standard nutritional interventions and identifying and treating cachexia at the earliest stage of development is advocated. Experts advocate for multimodal therapy to address symptoms that impact caloric intake, reduce chronic inflammation, and treat metabolic and endocrine derangements, which propagate the loss of weight. Treatment of insulin resistance may be a critical component of multimodal therapy for cancer cachexia and more research is needed.

Metabolic syndrome is a risk factor for colorectal adenoma and cancer: a study in a White population using the harmonized criteria

BACKGROUND

Metabolic syndrome (MetS) has been associated with colorectal adenomas and cancer. However, MetS definitions have changed over time, leading to a heterogeneity of patients included in previous studies and a substantial inextensibility of observations across time or eastern and western populations. Our aim was to evaluate the association of 'harmonized' criteria-defined MetS and its individual components with colorectal neoplasia and cancer in a western population.

METHODS

In this multicenter, cross-sectional study, we prospectively evaluated consecutive outpatients who underwent open-access colonoscopy over a 3-month period. MetS was diagnosed according to the 2009 'harmonized' criteria.

RESULTS

Out of 5707 patients enrolled, we found 213 cancers (3.7%), 1614 polyps (28.3%), 240 nonpolypoid lesions (4.2%), 95 laterally spreading tumors (1.6%). Polyps presented histological low-grade dysplasia in 72.9% of samples, while in 9.8%, high-grade dysplasia or in situ carcinoma was present; dysplasia rates for nonpolypoid lesions were 66.2% (low-grade) and 2.9% (high-grade/in situ carcinoma), while for laterally spreading tumors, 29.6% and 37%, respectively. Overall, MetS prevalence was 41.6%. MetS correlated with both adenomas [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.54-2.00] and cancer (OR: 1.92, 95% CI 1.42-2.58). MetS was the only risk factor for such colonic lesions in subjects younger than 50 years. For all colonic neoplasia, we found MetS and not its individual components to be significantly associated.

CONCLUSIONS

MetS is risk factor for cancer and adenoma in Whites, especially when younger than 50 years. MetS patients might be considered as a high-risk population also in colorectal cancer screening programs.

The role of metabolic syndrome variant in the malignant tumors progression

Metabolic syndrome (MS) is one of the leading risk factors for the development of some common cancers (endometrial cancer, postmenopausal breast cancer, colorectal cancer). Currently, a drug-induced metabolic syndrome related with androgen deprivation therapy in patients with prostate cancer represents a serious medical problem. Not only MS, or its individual components, but MS variants with different levels of leptin, adiponectin, visfatin, resistin are associated with tumor invasion, metastasis and survival rates in patients with MS-associated malignancies.

The combined effect of non-alcoholic fatty liver disease and metabolic syndrome on colorectal carcinoma mortality: a retrospective in Chinese females

BACKGROUND

This research aimed to investigate whether metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) had both individual and synergistic effects on the prognosis for female colorectal carcinoma (CRC) patients.

METHODS

The relationship between CRC prognosis and NAFLD as well as MetS was evaluated in 764 female participants. Based on the NAFLD level, patients were divided into significant NAFLD (SNAFLD), "moderate" and "severe" level, and non-SNAFLD, "non" and "mild" level. All the patients were categorized into four subgroups according to the status of SNAFLD and MetS and then a comparison of CRC prognosis among those four groups was performed.

RESULTS

NAFLD, SNAFLD, and MetS were independent factors for CRC-specific mortality with the adjustment of age and other confounders. The hazard ratio (HR) of CRC-specific mortality in MetS (+) SNAFLD (+) group was significantly higher than that in other three groups. Relative excess risk of interaction (RERI) was 2.203 with 95% CI ranged from 0.197 to 4.210, attributable proportion (AP) was 0.444 with range from 0.222 to 0.667, and synergy index (SI) of 2.256 with 95% CI from 1.252 to 4.065, indicating SNAFLD and MetS had a significant synergic effect on CRC-specific mortality.

CONCLUSIONS

SNAFLD and MetS are independent risk factors for CRC-specific mortality in females. Moreover, those two diseases have a synergistic effect on promoting CRC-specific mortality.

Interaction of smoking and metabolic syndrome in increasing the recurrence risk of colorectal cancer in a Chinese male cohort: a retrospective study

Whether smoking and metabolic syndrome (MetS) can affect colorectal carcinoma (CRC) prognosis remains debatable. Therefore, the present study aimed to examine the individual and combined effects of smoking and MetS on the prognosis of patients with localized CRC, including stage I to III disease. The relationship among smoking status, MetS, and CRC was assessed in 838 Chinese male patients. Cox proportional hazards regression analysis was used to evaluate CRC prognosis adjusted for clinicopathological variables. Relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (SI) were used to evaluate additive interactions between smoking and MetS. The presence of MetS was an independent risk factor for low rates of recurrence-free survival (RFS) but not for overall survival (OS). However, smoking was independently associated with both poor RFS and OS. Furthermore, the recurrence risk for current smokers with MetS was 1.62 times as high as the sum of risks in patients exposed to each risk factor alone. In conclusion, current smoking habit is a risk factor for both recurrence and cancer-specific mortality in CRC patients, while MetS is an independent predictor for CRC recurrence. Furthermore, these two factors have an additive effect on the recurrence risk of CRC.

Obesity and diabetes as prognostic factors in patients with colorectal cancer

Colorectal carcinoma is one of the most prevalent cancer types for both men and women. Prognosis of the disease is mostly defined by the stage. Localized disease has a better prognosis especially in earlier stages I and II. In addition most patients with more advanced localized stage III disease are expected to survive with a combination of surgery and adjuvant treatments. Progress in treatment of metastatic disease has led to median survivals exceeding 2 years and a minority of oligometastatic patients may survive even longer or be cured with multimodality therapy. Besides stage of the disease few prognostic factors are available to guide informative discussions with patients or guide therapeutic decisions. One area of research that may provide information in this direction is comorbidity conditions of the metabolic syndrome spectrum. Despite a significant body of literature investigating elements of the metabolic syndrome such as obesity and diabetes in isolation as risk and prognostic factors in colorectal cancer, a more restricted amount of research is dealing with the combination of these two factors as prognosticators of colorectal cancer. This paper will discuss published data on these factors and specifically their combination in the prognosis of colorectal cancer and will address some of their pathogenesis and therapy implications.

ADIPOQ rs266729 G/C gene polymorphism and plasmatic adipocytokines connect metabolic syndrome to colorectal cancer

Background: ADIPOQ gene, which encode for Adiponectin (APN), is sited on chromosome 3q27 and linked to a susceptibility locus for metabolic syndrome (MetS). The ADIPOQ rs266729 G/C gene polymorphism is significantly associated with low APN levels and linked to susceptibility to develop cancer. In addition, decreased APN serum levels are linked with tumor development and progression and inversely associated with markers of inflammation. Here, we investigate the influence of APN rs266729 G/C polymorphism on adipocytokine circulating levels and their association with MetS in colorectal cancer patients (CRC). Methods: Blood samples from 105 CRC patients (50 women and 55 men) with and without MetS were genotyped for APN rs266729 G/C polymorphism by TETRA ARMS PCR. ELISA assay was used to measure plasma levels of APN and inflammatory TNF-α cytokine. Biochemical and anthropometric parameters of MetS were also analyzed. Results: We found that CRC patients (N=75) with genotype rs266729G/C or carriers of G allele were associated with a significantly increased risk of MetS development (OR =2.9) compared to those with CC genotype (N=30). Also, CG/GG genotypes were associated with significantly lower plasma APN levels and higher TNF-α levels in comparison to CC genotype (P=0.034) and APN levels were decreased in relation to BMI increases (P=0.001). Conclusions: Our findings show that APN rs266729 G/C polymorphism is associated with lower APN levels in CRC patients, indicating that decreased circulating levels of APN may be a determinant risk factor for CRC in MetS patients.

Correlation between serum lipid levels and colorectal polyps

AIM

To explore the characteristics of serum lipids in patients with colorectal polyps.

METHODS

The levels of serum lipids were compared between patients with colorectal polyps and controls. Then, the levels of serum lipids were analyzed according to the different clinical characteristics of colorectal polyps.

RESULTS

The levels of triacylglycerol (TG) (1.62 ± 1.12), total cholesterol (5.16 ± 1.19), and low density lipoprotein-cholesterol (LDL-C) (3.36 ± 0.95) in the colorectal polyp group were significantly higher than those of the control group (t = 2.358, 4.437, and 5.137, P = 0.019, 0.000, and 0.000, respectively). The level of TG was significantly higher (t = 2.129, P = 0.035), and the level of high density lipoprotein-cholesterol (HDL-C) was significantly lower (t = -2.711, P = 0.008) in colorectal polyp patients with fatty liver than in those without. The level of LDL-C was significantly higher in colorectal polyp patients with gastric polyps than in those without (t = 2.201, P = 0.038). There were no significant differences in the 1evels of serum lipids between the adenoma group and non-adenoma group, between the villous adenoma group and non-villous adenoma group, between the left colon and rectum polyp group and right colon polyp group, or between the male and female groups. The incidence of fatty liver in patients with colorectal polyps was related to the incidence of hyperlipidemia.

CONCLUSION

There is a significant correlation between hypertriglyceride, hypercholesteremia, high LDL-C levels, and colorectal polyps. Hypertriglyceride and low HDL-C level may be related to colorectal polyps with fatty liver. High LDL-C level may be related to colorectal polyps with gastric polyps. The incidence of fatty liver in patients with colorectal polyps is related to the incidence of hyperlipidemia.

Metabolic syndrome contributes to an increased recurrence risk of non-metastatic colorectal cancer

Objectives

Epidemiological data suggests a close link between metabolic syndrome (MetS) and non-metastatic colorectal cancer (NMCRC). However, the relationship between MetS and the outcome of NMCRC is less well understood. We aim to evaluate the impact of MetS on the prognosis in NMCRC patients.

Methods

We performed a large cohort study of 1069 NMCRC patients. The Kaplan-Meier method was used to calculate the cumulative survival rate. Cox proportional hazard regression models were used to analyze the prognosis associated with MetS adjusting for clinicopathologic variables.

Results

MetS was identified in 20.7% of NMCRC patients. Patients with MetS were more likely to be older, higher levels of blood glucose, triglycerides, high density lipoprotein, and uric acid than patients without MS (P < 0.05 for all). During a mean period of 59.6 months follow-up, patients with MetS had a statistically significantly lower rate of disease-free survival (DFS) than the patients without MetS (P = 0.014), especially local recurrence (P = 0.040). However, there was no difference in overall survival (P = 0.116). Multivariate analysis showed that the presence of MetS was an independent risk factor for DFS (HR = 0.733, 95%CI 0.545–0.987, P = 0.041), but not for OS (P = 0.118).

Conclusions

MetS is associated with an increased recurrence risk of NMCRC.

Clinical features of colorectal neoplasm patients with metabolic syndrome

AIM: To investigate the clinical features of colorectal neoplasm patients with metabolic syndrome (MS).

METHODS: A retrospective analysis was performed of clinical data for patients who were diagnosed with colorectal neoplasm with MS from May 2012 to May 2015.

RESULTS: A total of 107 patients were included. There were 72 males and 35 females, and their mean age was 66.84 years ± 10.58 years. There were 40 cases of adenomas and 67 cases of colorectal cancer. There was no significant difference (P > 0.05) in the rate of reduced high density lipoprotein-cholesterol (HDL-C) [29 (72.5%) vs 53(79.1%)] between patients with adenomas and those with colorectal cancer, but the rate of elevated triacylglycerol [14 (35.0%) vs 45 (67.2%)] differed significantly (P < 0.05). The rates of elevated CEA and CA199 showed no significant difference between patients with adenomas and colorectal cancer (P > 0.05); however, the rate of elevated CA125 and the rate of elevation of two or more of the three tumor markers were significantly higher in the colorectal cancer group than in the adenoma group (P < 0.05). In colorectal neoplasm patients with MS, 20 developed carcinoma metastases, and 16 cases died; the median survival time was 33 mo.

CONCLUSION: Colorectal neoplasm patients with metabolic syndrome are always diagnosed at old ages, and high level of TG may play a role in the evolution of colorectal adenomas to colorectal cancer. Joint detection of multiple tumor markers can be used to distinguish benign and malignant lesions in these patients.

Validation of the Asia Pacific Colorectal Screening (APCS) score in a Western population: An alternative screening tool

BACKGROUND AND AIM

Colorectal cancer (CRC) screening is based on colonoscopy or fecal occult blood tests, but is imperfect and costly. The Asia Pacific Colorectal Screening Score (APCS) is derived from age, sex, family history of CRC, and smoking history and has been validated in Asian populations. Validation in a Western population is, however, yet to be tested.

METHODS

In a teaching hospital, patients underwent colonoscopy for standard indications and screening over 18 months. Data was collected on age, sex, family history of CRC, smoking, weight, ethnicity, and symptoms. Evaluation of the APCS to predict colonoscopy findings (polyps, adenoma, high risk adenoma, and CRC) was performed.

RESULTS

A total of 645 patients were prospectively recruited (46.7% male, median age 57 years); 17.8% were average risk (AR), 50.9% were moderate risk (MR), and 31.3% high risk (HR) on APCS. High risk adenomas (AA) were seen in 14.9% of the HR, 5.2% MR, and 0.9% LR patients, P < 0.0001. Comparing HR and MR to AR patients demonstrated significantly elevated relative risk (RR) for AA: 17.1 (95% confidence interval [CI] 2.4-123; P = 0.0001), and adenoma 6.0 (0.80-44.3; P = 0.044). Comparing HR to MR groups for AA, the RR was 2.87 (1.62-5.06; P = 0.0001). Symptoms did not predict findings (odds ratio [OR]: 1.06 [0.75-1.48]; P = 0.75). Body mass index (BMI) <20 kg/m(2) was protective against colonic polyps (OR: 0.28, 95%CI: 0.11-0.74; P = 0.010), adenoma (0.08, 0.01-0.62; P = 0.015), and AA (perfect prediction, OR 2.35 × 10(-8)).

CONCLUSIONS

APCS predicts colonic findings in a Western population, to a greater extent than in Asians, independent to symptoms. Low body weight carries a strong protective effect against colonic neoplasia.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.

Utility of the Asia-Pacific colorectal screening scoring system and the presence of metabolic syndrome components in screening for sporadic colorectal cancer

AIM: To determine the utility of the Asia-Pacific colorectal screening (APCS) scoring system and metabolic syndrome components in individual screening for sporadic colorectal cancer.

METHODS: The subjects were patients admitted to the Peking University People’s Hospital for colonoscopy between October 2012 and July 2013. Clinical information, including patient willingness to undergo colonoscopy, medical history, endoscopic findings, histology, and other information, was collected, and the patients were grouped according to APCS scores and the presence of metabolic syndrome components. Colorectal tumor detection rates were compared between the groups.

RESULTS: A total of 219 patients were included in the study, 108 were male and 111 were female, resulting in a male-to-female ratio of 1:1.03. The average age of the patients was 56.8 ± 13.7 years. According to APCS scores, 88 (40.2%) patients were included in the average-risk (AR) group, 113 (51.6%) patients were included in the moderate-risk (MR) group, and 18 (8.2%) patients were included in the high-risk (HR) group. Colorectal tumors were detected in 69 (31.5%) subjects, and the detection rates in the AR, MR, and HR groups were 15.9%, 36.3%, and 77.8%, respectively. The difference in the detection rates between the three groups was statistically significant (P < 0.01). The combined detection rate of colorectal tumors in the APCS MR and HR groups was 42.0%. However, patients in the MR and HR groups who presented with metabolic syndrome components, in particular obesity, exhibited a significantly higher colorectal tumor detection rate (59.5%) than did those without these components (19.2%, P < 0.01) and those who underwent colonoscopy because of doctor’s recommendation (36.5%, P < 0.01).

CONCLUSION: The APCS scoring system can be used in individual screening for sporadic colorectal cancer. The combined use of APCS scores and the metabolic syndrome components, in particular obesity, will significantly improve the efficacy of individual colorectal cancer screening.

Metabolic syndrome is associated with increased prevalence of advanced colorectal polyps

OBJECTIVES

To examine the association between metabolic syndrome (MetS) and/or its components and colorectal neoplasms in adult population undergoing screening colonoscopy.

DESIGN

Cross-sectional study.

SETTING

Institute of Gastroenterology, Kaplan Medical Center, Rehovot, Israel.

PARTICIPANTS

Two hundred ninety nine consecutive outpatients undergoing screening colonoscopy.

MEASUREMENTS

MetS was determined according to the Adult Treatment Panel III of the National Cholesterol Education Program (ATP III) criteria. Blood test results and other clinical data were retrieved from the electronic medical records.

RESULTS

In 94 patients (31.8%) polyps were detected. Thirty two (34%) of the polyps were advanced. Eighty one percent of patients with an advanced polyp met the criteria for MetS. About the same MetS prevalence (84%) was found in men, but not in women. An advanced polyp was detected in 14% of patients with MetS, compared to 5% of patients without MetS. Odds ratio for having an advanced polyp in a patient with MetS compared to a patient without MetS was 10.64.

CONCLUSION

MetS was found to be a risk factor for advanced polyps. This association is suggestive of the need that patients with MetS should be urged to have a screening colonoscopy.

Colorectal cancer association with metabolic syndrome and its components: a systematic review with meta-analysis

We performed a systematic review and meta-analysis of the empirical evidence on the association of metabolic syndrome and its components with colorectal cancer incidence and mortality. A systematic literature search of multiple electronic databases was conducted and complemented by cross-referencing to identify studies published before 31 October 2012. Every included study was to report risk estimates with 95 % confidence intervals for the association between metabolic syndrome and colorectal cancer (incidence or mortality). Core items of identified studies were independently extracted by two reviewers, and results were summarized by standard methods of meta-analysis. We identified 17 studies, which reported on 49 data sets with 11,462 cancer cases. Metabolic syndrome was associated with an increased risk of colorectal cancer incidence and mortality in both men (RR: 1.33, 95 % CI 1.18-1.50, and 1.36, 1.25-1.48, respectively) and women (RR: 1.41, 1.18-1.70, and 1.16, 1.03-1.30, respectively). The risk estimates changed little depending on type of study (cohort vs non cohort), populations (US, Europe, Asia), cancer site (colon and rectum), or definition of the syndrome. The risk estimates for any single factor of the syndrome were significant for higher values of BMI/waist (RR: 1.19, 95 % CI 1.10-1.28), dysglycemia (RR: 1.29, 1.11-1.49), and higher blood pressure (RR: 1.09, 1.01-1.18). Dysglycemia and/or higher BMI/waist explained most of the risk associated with metabolic syndrome. Metabolic syndrome is associated with an increased risk of colorectal cancer incidence and mortality in both sexes. The risk conveyed by the full syndrome is not superior to the sum of its parts.

Metabolic syndrome and risk of cancer: a systematic review and meta-analysis

OBJECTIVE

Available evidence supports the emerging hypothesis that metabolic syndrome may be associated with the risk of some common cancers. We did a systematic review and meta-analysis to assess the association between metabolic syndrome and risk of cancer at different sites.

RESEARCH DESIGN AND METHODS

We conducted an electronic search for articles published through October 2011 without restrictions and by reviewing reference lists from retrieved articles. Every included study was to report risk estimates with 95% CIs for the association between metabolic syndrome and cancer.

RESULTS

We analyzed 116 datasets from 43 articles, including 38,940 cases of cancer. In cohort studies in men, the presence of metabolic syndrome was associated with liver (relative risk 1.43, P < 0.0001), colorectal (1.25, P < 0.001), and bladder cancer (1.10, P = 0.013). In cohort studies in women, the presence of metabolic syndrome was associated with endometrial (1.61, P = 0.001), pancreatic (1.58, P < 0.0001), breast postmenopausal (1.56, P = 0.017), rectal (1.52, P = 0.005), and colorectal (1.34, P = 0.006) cancers. Associations with metabolic syndrome were stronger in women than in men for pancreatic (P = 0.01) and rectal (P = 0.01) cancers. Associations were different between ethnic groups: we recorded stronger associations in Asia populations for liver cancer (P = 0.002), in European populations for colorectal cancer in women (P = 0.004), and in U.S. populations (whites) for prostate cancer (P = 0.001).

CONCLUSIONS

Metabolic syndrome is associated with increased risk of common cancers; for some cancers, the risk differs betweens sexes, populations, and definitions of metabolic syndrome.

IGF-1 and its receptor in esophageal cancer: association with adenocarcinoma and visceral obesity

OBJECTIVES

The insulin-like growth factor (IGF) pathway and visceral obesity have been independently linked with esophageal cancer. This study aimed to delineate the differential and interlinked role of visceral obesity and the IGF-1 system in esophageal adenocarcinoma and esophageal squamous-cell carcinoma (SCC).

METHODS

IGF-1 receptor (IGF-1R) mRNA and protein were examined in esophageal SCC (KYSE 410, OE21) and esophageal adenocarcinoma (OE19, OE33) cell lines by western blotting. Tumor cell proliferation in response to IGF-1 was assessed by bromodeoxyuridine incorporation assay. In esophageal tumor sections, expression of IGF-1R and CD68(+) cell numbers were assessed by immunohistochemistry. IGF-1 was measured in serum from esophageal cancer patients, Barrett's esophagus patients, and healthy controls by enzyme-linked immunosorbent assay.

RESULTS

Higher IGF-1R protein expressions were observed in SCC cells compared with esophageal adenocarcinoma cells however only adenocarcinoma cell lines significantly increased proliferation in response to IGF-1 (P<0.01). Serum IGF-1 levels were highest in esophageal adenocarcinoma patients (P<0.01) and higher in viscerally obese vs. nonobese (P<0.05) patients. In resected esophageal cancer, increased expression of IGF-1R was observed in the tumor and invasive edge compared with tumor-associated stroma (P<0.05), which coincided with increased CD68(+) cells in stromal tissue surrounding invasive tumor edge (P<0.01).

CONCLUSIONS

This novel study examined the differential role of the IGF system in esophageal adenocarcinoma and SCC, and its association with visceral obesity. These results indicate that the IGF-1 axis has a key role in malignant progression of esophageal cancer, and represents a plausible mechanism through which visceral obesity impacts on esophageal adenocarcinoma risk and tumor biology.

The role of resistin in colorectal cancer

BACKGROUND

To date the role of resistin in colorectal cancer (CRC) is far from being elucidated. The aim of this study was to investigate the association between serum resistin levels and CRC in relation to known risk/protective factors including anthropometric, metabolic, inflammatory parameters as well as lifestyle individual characteristics.

METHODS

40 CRC patients and 40 controls were enrolled. Body weight, height, waist circumference and blood pressure were recorded. Fasting plasma glucose, lipids, C-reactive protein (CRP) and resistin levels were measured. Metabolic Syndrome (MS) was defined according to the harmonized definition.

RESULTS

Resistin levels were significantly higher in CRC patients than in controls (p=0.028) and gradually increased with tumor stage progression (p=0.042). A high resistin level was statistically significant determinant of CRC after adjusting for age, sex, body mass index and lifestyle parameters (p=0.029). Resistin showed a strong association with CRP levels (p ≤ 0.0001). In stepwise regression analysis CRP remained the only independent predictor of both resistin levels (p=0.001) and CRC risk (p=0.021).

CONCLUSIONS

These results clarify the nature of the association between resistin and CRC risk suggesting that the proinflammatory state of cancer, rather than the clinical diagnosis of CRC itself or its link with obesity and MS, may govern this association.

Visceral obesity, metabolic syndrome, insulin resistance and cancer

This paper presents emerging evidence linking visceral adiposity and the metabolic syndrome (MetSyn) with carcinogenesis. The link between obesity and cancer has been clearly identified in a multitude of robust epidemiological studies. Research is now focusing on the role of visceral adipose tissue in carcinogenesis; as it is recognised as an important metabolic tissue that secretes factors that systemically alter the immunological, metabolic and endocrine milieu. Excess visceral adipose tissue gives rise to a state of chronic systemic inflammation with associated insulin resistance and dysmetabolism, collectively known as the MetSyn. Prospective cohort studies have shown associations between visceral adiposity, the MetSyn and increased risk of breast cancer, colorectal cancer and oesophageal adenocarcinoma. Furthermore, visceral adiposity and the MetSyn have been associated with increased tumour progression and reduced survival. The mechanisms by which visceral adiposity and the MetSyn are thought to promote tumorigenesis are manifold. These include alterations in adipokine secretion and cell signalling pathways. In addition, hyperinsulinaemia, subsequent insulin resistance and stimulation of the insulin-like growth factor-1 axis have all been linked with visceral adiposity and promote tumour progression. Furthermore, the abundance of inflammatory cells in visceral adipose tissue, including macrophages and T-cells, create systemic inflammation and a pro-tumorigenic environment. It is clear from current research that excess visceral adiposity and associated dysmetabolism play a central role in the pathogenesis of certain cancer types. Further research is required to elucidate the exact mechanisms at play and identify potential targets for intervention.

Anaesthetic considerations with the metabolic syndrome

The rising incidence of obesity has led to increased prevalence of a distinct, obesity-related metabolic syndrome. This syndrome is characterized by truncal obesity, insulin resistance, altered lipid levels, and hypertension. Definition of the metabolic syndrome rests on a set of clinical criteria instead of a single diagnostic test. It carries a different risk profile than obesity alone, and poses special challenges for the anaesthesiologist. These include preoperative risk stratification for common comorbidities, identifying reasonable thresholds for implementing preoperative risk reduction, overcoming obesity-related issues in intraoperative management, and delivering safe postoperative care. The metabolic syndrome predisposes to coronary artery disease, congestive heart failure, obstructive sleep apnoea, pulmonary dysfunction, and deep venous thrombosis. Because its different presentations can have different risk profiles, anaesthesiologists should assess the cumulative risk of each component of the metabolic syndrome separately, which significantly complicates preoperative management. Since obesity itself is difficult to treat, preoperative risk reduction can be difficult. Few data exist to inform best practice as to the anaesthetic care of patients with metabolic syndrome. This review evaluates and synthesizes current evidence regarding perioperative care for patients with the metabolic syndrome, including indications for preoperative testing; use of aspirin, β-blockers, statins, heparin, and angiotensin-converting enzyme inhibitors; anaesthetic strategies including regional anaesthesia; and postoperative management including continuous positive pressure ventilation by mask, prevention of pulmonary embolism, and indications for advanced respiratory monitoring.