Plasma Leptin Levels and Risk of Incident Cancer: Results from the Dallas Heart Study

Association of Serum Leptin With Body Mass Index in Gallbladder Cancer Patients: A Pilot Study

BACKGROUND

Leptin has been proposed to be a link between obesity and the increased incidence of various cancers like breast cancer, colon cancer, gastric cancer, etc. The role of leptin in gallbladder cancer is largely undetermined. Moreover, no study has evaluated serum leptin levels and their correlation with clinicopathological characteristics and serum tumour markers in gallbladder cancer (GBC). Therefore, the present study was planned.

METHODS

A cross-sectional study was conducted in a tertiary care hospital in Northern India after obtaining ethical approval from the institution. Forty GBC patients staged as per American Joint Committee on Cancer (AJCC) 8th staging system were recruited along with 40 healthy controls. Serum leptin was assayed by sandwich enzyme-linked immunosorbent assay (ELISA) and tumour markers (CA19-9, CEA and CA125) by Chemiluminescence. ROC, Mann Whitney U test, Linear regression and Spearman correlation was performed using Statistical Product and Service Solutions (SPSS) (IBM SPSS Statistics for Windows, Version 25.0, Armonk, NY). BMI was also assessed for both groups.

RESULTS

Median BMI for GBC patients was 19.46 (IQR 17.61-22.36). Median serum leptin levels were significantly lower (2.09 (IQR 1.01-7.76) ng/mL) in GBC patients as compared to controls (12.32 (IQR 10.50-14.72) ng/mL). AUC was 0.84 with 100% sensitivity and 75% specificity at 7.57 ng/mL. Serum leptin was not associated with cancer stage, resectability, metastasis, liver infiltration, or tumour markers on linear regression (p=0.74, adjusted R square = -0.07). A significant positive correlation was found between BMI and serum leptin in GBC patients (p=0.00).

CONCLUSIONS

Lower BMI and relatively lean presentation of GBC patients may account for low serum leptin levels.

The Head-to-Toe Hormone: Leptin as an Extensive Modulator of Physiologic Systems

Leptin is a well-known hunger-sensing peptide hormone. The role of leptin in weight gain and metabolic homeostasis has been explored for the past two decades. In this review, we have tried to shed light upon the impact of leptin signaling on health and diseases. At low or moderate levels, this peptide hormone supports physiological roles, but at chronically higher doses exhibits detrimental effects on various systems. The untoward effects we observe with chronically higher levels of leptin are due to their receptor-mediated effect or due to leptin resistance and are not well studied. This review will help us in understanding the non-anorexic roles of leptin, including their contribution to the metabolism of various systems and inflammation. We will be able to get an alternative perspective regarding the physiological and pathological roles of this mysterious peptide hormone.

Emerging Roles for Browning of White Adipose Tissue in Prostate Cancer Malignant Behaviour

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.

Circulating adiponectin and leptin and risk of overall and aggressive prostate cancer: a systematic review and meta-analysis

Obesity is associated with an increased risk of advanced, recurrent and fatal prostate cancer. Adipokines may mediate this relationship. We conducted a systematic review and meta-analysis of associations of leptin and adiponectin with overall and aggressive prostate cancer. Bibliographic databases were systematically searched up to 1st April 2017. Log Odds Ratios (ORs) per 2.5 unit increase in adiponectin or leptin levels were derived and pooled. All analyses were stratified by study type (cross-sectional/prospective). 746 papers were retrieved, 34 eligible studies identified, 31 of these could be included in the meta-analysis. Leptin was not consistently associated with overall prostate cancer (pooled OR 1.00, 95%CI 0.98-1.02, per 2.5 ng/ml increase, prospective study OR 0.97, 95%CI 0.95-0.99, cross-sectional study OR 1.19, 95%CI 1.13-1.26) and there was weak evidence of a positive association with aggressive disease (OR 1.03, 95%CI 1.00-1.06). There was also weak evidence of a small inverse association of adiponectin with overall prostate cancer (OR 0.96, 95%CI 0.93-0.99, per 2.5 µg/ml increase), but less evidence of an association with aggressive disease (OR 0.98, 95%CI 0.94-1.01). The magnitude of any effects are small, therefore levels of circulating adiponectin or leptin alone are unlikely to be useful biomarkers of risk or prognosis.

Chronic inflammation towards cancer incidence: A systematic review and meta-analysis of epidemiological studies

This systematic review and meta-analysis provides epidemiological data on the relationship between chronic inflammation, as measured by inflammatory blood parameters, and cancer incidence. Two independent researchers searched PubMed, Web Of Science and Embase databases until October 2020. In vitro studies, animal studies, studies with chronically-ill subjects or cross-sectional studies were excluded. Quality was assessed with the Newcastle-Ottawa scale. The 59 nested case-control, 6 nested case-cohort and 42 prospective cohort studies considered 119 different inflammatory markers (top three: CRP, fibrinogen and IL6) and 26 cancer types (top five: colorectal, lung, breast, overall and prostate cancer). Nineteen meta-analyses resulted in ten significant positive associations: CRP-breast (OR = 1.23[1.05-1.43];HR = 1.14[1.01-1.28)), CRP-colorectal (OR = 1.34[1.11-1.60]), CRP-lung (HR = 2.03[1.59-2.60]), fibrinogen-lung (OR = 2.56[1.86-3.54]), IL6-lung (OR = 1.41[1.12-1.78]), CRP-ovarian (OR = 1.41[1.10-1.80]), CRP-prostate (HR = 1.09[1.03-1.15]), CRP-overall (HR = 1.35[1.16-1.57]) and fibrinogen-overall (OR = 1.22[1.07-1.39]). Study quality improvements can be done by better verification of inflammatory status (more than one baseline measurement of one parameter), adjusting for important confounders and ensuring long-term follow-up.

The Suitability of FGF21 and FGF23 as New Biomarkers in Endometrial Cancer Patients

Endometrial cancer is one of the most common cancers of the reproductive organ in women. The incidence of it increases from year to year. In our study we assessed role of FGF21 and FGF23 in the diagnostics of patients with endometrial cancer. The study involved 182 patients, who were undergoing abrasion due to perimenopausal bleeding. FGF21, FGF23, and leptin concentration were quantified in serum by multiplex fluorescent bead-based immunoassays (Luminex Corporation). The median of FGF21 protein (181.8 pg/mL) as well as leptin (16.9 ng/mL) in patients with endometrial cancer was statistically significant higher compared to median of those proteins among patients from control group (152.1 pg/mL and 14.1 ng/mL, respectively). However, no significant differences were found in these groups at median FGF23 concentrations. For FGF21 and leptin, the AUC values were 0.81/0.79, while FGF23, the AUC values was 0.66 for all study patients. Leptin and FGF21 concentrations were statistically significantly higher in patients with poorly differentiated G3 tumors compared to patients with moderately differentiated G2 tumors and with moderately differentiated G2 with highly differentiated G1 respectively: p = 0.02/p = 0.03 and p = 0.02/p = 0.005. FGF21 appears to be useful as a diagnostic as well as prognostic factor in patients with endometrioid endometrial carcinoma.

The Role of Diet in Cancer Prevention and Chemotherapy Efficacy

Despite great advances in treatment, cancer remains a leading cause of death worldwide. Diet can greatly impact health, while caloric restriction and fasting have putative benefits for disease prevention and longevity. Strong epidemiological associations exist between obesity and cancer, whereas healthy diets can reduce cancer risk. However, less is known about how diet might impact cancer once it has been diagnosed and particularly how diet can impact cancer treatment. In the present review, we discuss the links between obesity, diet, and cancer. We explore potential mechanisms by which diet can improve cancer outcomes, including through hormonal, metabolic, and immune/inflammatory effects, and present the limited clinical research that has been published in this arena. Though data are sparse, diet intervention may reduce toxicity, improve chemotherapy efficacy, and lower the risk of long-term complications in cancer patients. Thus, it is important that we understand and expand the science of this important but complex adjunctive cancer treatment strategy.

The association of lymphotoxin-beta receptor with the subsequent diagnosis of incident gastrointestinal cancer: results from the Dallas Heart Study

Background

Lymphotoxin-beta receptor (LTβR) is an immunological protein associated with inflammation, and from preclinical studies is implicated in tumorigenesis. The epidemiological relationships with cancer are unknown, hence this study investigated their associations.

Methods

From a multiethnic population-based cohort, 3,032 participants without a prevalent cancer (a diagnosis prior to or within one year of enrollment) at baseline underwent measurement of plasma LTβR. These participants were followed for incident cancer using the Texas Cancer Registry (TCR).

Results

Over a median follow-up of 12.1 years, 178 participants developed incident cancer, of which 30 participants developed incident gastrointestinal (GI) cancer. Median plasma LTβR (1.10 vs. 1.00 ng/mL, P<0.02) levels were higher in individuals with overall incident cancer compared to those without cancer. After adjustments for age, sex, and race/ethnicity, these relationships were no longer significant. When analyses were stratified by cancer type, LTβR was positively associated with GI cancer after adjustments: HR, 95% CI per 1-standard deviation increase in concentration 2.64 (1.23-5.68), P=0.013. LTβR stratified by quartiles was significantly associated temporally with the risk of incident GI cancer, log-rank: P=0.011. The median interval to incident GI cancer diagnosis was 5.9 years.

Conclusions

Increased plasma levels of LTβR are associated with the development of GI cancer. The antecedent findings years prior to a subsequent diagnosis of incident GI cancer suggest a role for LTβR in the pathogenesis of GI cancer. Further studies are needed to determine if LTβR can serve as an immune biomarker for GI cancer, in particular hepatocellular and colorectal cancers.

Association of Adipokines and Insulin, Which Have a Role in Obesity, with Colorectal Cancer

Obesity-related diseases are an important part of public health; and obesity is related with colorectal cancer. Adipocyte hypertrophy and visceral adipose tissue accumulation can cause adipocitis-related diseases and pathogenic adipocyte formation. Adipose tissue has a very important and active role in immune response formation. Cytokines/adipokines, which are secreted from adipose tissue, have an active role in communication between adipocytes and macrophages. Thus, visceral adipocyte is related with low-grade chronic systemic inflammation. Adipocytes have an important role in colorectal cancer pathogenesis because of proinflammatory cytokines, growth factors, and hormones secretion. Most highlighted cytokines are adiponectin, resistin, and ghrelin. Also, insulin resistance, glucose intolerance, increased plasma insulin levels, body mass index, insulin-like growth factor (IGF-1), glucose, and serum free fatty acids levels are considered to be related with colorectal cancer pathogenesis. Thus, in this review, we focus on the role of adipokines and insulin in colorectal cancer.

An Analysis of Individual Body Fat Depots and Risk of Developing Cancer: Insights From the Dallas Heart Study

OBJECTIVE

To examine the association between specific adipose tissue depots and the risk of incident cancer in the Dallas Heart Study.

PATIENTS AND METHODS

Individuals without prevalent cancer in the Dallas Heart Study underwent quantification of adipose depots: visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue, and liver fat by magnetic resonance imaging, and subcutaneous lower-body fat (LBF) by dual-energy X-ray absorptiometry from January 1, 2000, through December 31, 2002, and were observed for the development of cancer for up to 12 years. Multivariable Cox proportional hazards modeling was performed to examine the association between fat depots and cancer.

RESULTS

Of 2627 participants (median age, 43 years; 69% nonwhite race), 167 (6.4%) developed cancer. The most common primary sites of cancer were the breast (in women) and the prostate (in men). In multivariable models adjusted for age, sex, race, smoking, alcohol use, family history of malignancy, and body mass index, a 1-SD increase in VAT was not associated with increased risk of cancer (hazard ratio [HR], 0.94; 95% CI, 0.77-1.14). In contrast, each 1-SD increase in LBF was associated with a reduced incidence of cancer (HR, 0.69; 95% CI, 0.52-0.92) in the fully adjusted model.

CONCLUSIONS

In this study, adiposity-associated cancer risk was heterogeneous and varied by fat depot: VAT was not independently associated with incident cancer, and LBF seemed to protect against cancer development. Further studies of the adiposity-cancer relationship, including serial assessments, are needed to better elucidate this relationship.