Obesity, diabetes, and other factors in relation to survival after endometrial cancer diagnosis

Regulation of insulin-like growth factor signaling by metformin in endometrial cancer cells

Obesity, diabetes and insulin resistance are marked risk factors that promote the development of type I endometrial cancer. Previous studies have demonstrated that insulin-like growth factor 1 (IGF-1) and IGF-2 promote cell proliferation in endometrial cancer cells, while metformin reverses this effect and inhibits cell proliferation. However, the effects of metformin on the regulation of the IGF signaling pathway are unclear. The aim of this study was to investigate the regulation of IGF signaling by metformin in endometrial cancer cells, and to determine the effects of metformin combined with IGF-1 receptor (IGF-1R) inhibitor on cell proliferation and apoptosis. Cell proliferation was assessed following exposure of Ishikawa and HEC-1B endometrial cancer cell lines to metformin and/or the IGF-1R inhibitor, PPP. Apoptosis was assessed by TdT-mediated dUTP nick end labeling assay. Metformin was observed to downregulate IGF-1R and upregulate IGF binding protein-1 (IGFBP-1) mRNA and protein expression, while compound C, an adenosine monophosphate protein kinase inhibitor, reversed this effect. Metformin administered with PPP inhibited endometrial cancer cell proliferation to a greater degree than treatment with either agent alone. At high concentrations (1 or 2 mM), metformin induced apoptosis in endometrial cancer cells. Metformin combined with IGF-1R axis inhibitors may act synergistically to kill tumor cells, as metformin was shown to delay and prevent IGF-1R feedback. In conclusion, this study supported the results of animal studies and subclinical studies, demonstrating the feasibility of metformin combined with IGF-1R axis inhibitors in the treatment of endometrial cancer.

Anti-diabetic doses of metformin decrease proliferation markers in tumors of patients with endometrial cancer

BACKGROUND

Metformin has been associated with reduced cancer risk. The mechanisms underlying this cancer protective effect remain unknown.

METHODS

"Window of opportunity" study of metformin in women with operable endometrial cancer (EC). Eleven newly diagnosed, untreated, non-diabetic patients with EC received metformin 500 mg tid from diagnostic biopsy to surgery. Fasting plasma insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 1 (IGFBP-1) and insulin-like growth factor binding protein 7 (IGFBP-7) measurements were taken before and after metformin treatment. Ki-67, pAMPK, and pS6 immunohistochemistry staining was performed on the endometrial cancer before and after metformin treatment and was compared to a control group of 10 women with EC who did not receive metformin.

RESULTS

Metformin was administered for a mean of 36.6 days. None of the patients suffered side effects requiring withdrawal from the study. The study group comprised 8 patients with endometrioid EC, and 3 non-endometrioid EC, with a mean follow-up time of 57 months. Mean plasma insulin (p=0.0005), IGF-1 (p=0.001), and IGFBP-7 (p=0.0098) were significantly reduced after metformin treatment. A clear reduction in ki-67 and pS6 expression was observed by both conventional light microscope analysis and digital image analysis with a significant mean reduction in percentage of cells staining for ki-67 (9.7%, P=0.02) and pS6 (31%, P=0.03). In the non-treated control group expression was similar between the biopsy and the surgical specimens.

CONCLUSIONS

This pilot trial presents biological evidence consistent with anti-proliferative effects of metformin in women with EC in the clinical setting.

Bariatric surgery-induced weight loss changes immune markers in the endometrium of morbidly obese women

BACKGROUND

Obesity has been linked to abnormal estrogen regulation, endometrial hyperplasia, and endometrial cancer (EC). Our group has shown that hormone receptor expression profiles in the endometria of morbidly obese women change with weight loss, in some cases concordantly with resolving hyperplasia; however other potential drivers of neoplasia, including altered immunologic tolerance exist. The objective of this study was to evaluate the effect of bariatric surgery induced weight loss on the expression patterns of nonhormone receptor biomarkers associated with cancer and immunity.

METHODS

Endometrial biopsies were obtained from 59 asymptomatic, morbidly obese women at the time of bariatric surgery and again 1 year postsurgery. Tissue microarrays were created and immunohistochemical stains for CD3, CD20, and PTEN were performed on all samples and evaluated by 2 blinded pathologists independently. Approximately 50% of participants had sufficient tissue for analysis at both visits. McNemar/Bowker tests of symmetry were performed to compare proportions between categories for matched pairs (pre- and post-treatment).

RESULTS

Endometrial hyperplasia was identified in 4 women despite negative clinical histories and resolution of hyperplasia after weight loss occurred in 3 women. While overall no significant differences were observed between matched pre and postsurgery levels of CD20 and CD3 positive cells, a tendency toward decreased expression levels from baseline status was observed for CD20. No differences were observed for PTEN.

CONCLUSION

Our data demonstrate that the prevalence of endometrial pathology appears to be partially mitigated by weight loss. Weight loss is associated with alterations in the hormone receptor profiles, but these data suggest that changes in the immune response, as measure be expression of CD20+, may be relevant targets for EC prevention research.

Impact of body mass index on the prognosis of Korean women with endometrioid adenocarcinoma of the uterus: A cohort study

OBJECTIVE

To analyze how pretreatment body mass index relates to known endometrial cancer prognostic factors and how it impacts the disease-free survival and cause-specific survival of Korean women with endometrial cancer.

METHODS

The patients were divided into the non-obese (<25 kg/m(2)) and obese groups (≥25 kg/m(2)) according to their pretreatment body mass index. The 25 kg/m(2) body mass index cut-off was based on the World Health Organization criteria for Asian people. The two groups were compared in terms of their clinicopathological characteristics and survival outcomes.

RESULTS

A total of 213 consecutive patients with endometrioid adenocarcinoma of the uterus met the eligibility criteria of this study and were included in the analysis. Of these patients, 105 patients had a body mass index less than 25 kg/m(2) (non-obese group) and 108 patients had a body mass index equal to or more than 25 kg/m(2) (obese group). The two groups did not differ in terms of age, menopause, parity, height, FIGO (International Federation of Obstetrics and Gynecology) stage, tumor grade, tumor size, myometrial invasion, lymphovascular space invasion, cytology, and lymph node metastasis. Body mass index was not a significant factor for disease-free and cause-specific survival in univariate analysis, and after adjusting for all prognostic factors that were significant in univariate analysis, it did not associate significantly with disease-free and cause-specific survival.

CONCLUSION

In Korean women with endometrioid adenocarcinoma of the uterus, a high pretreatment body mass index did not associate with other prognostic factors and had little impact on the disease-free survival and cause-specific survival of these women.

The impact of BMI on quality of life in obese endometrial cancer survivors: does size matter?

BACKGROUND

Survivorship and quality of life issues are becoming increasingly relevant in endometrial cancer as a result of the marked increase in incidence of the disease combined with excellent and improving long term survival.

OBJECTIVE

The purpose of this study was to evaluate the effect of obesity on quality of life (QoL) in endometrial cancer survivors.

METHODS

Participants were endometrioid endometrial cancer survivors diagnosed between 2008 and 2013. Quality of life was measured through the European Organisation for Research and Treatment of Cancer (EORTC) quality of life questionnaire (QLQ-C30, version 3.0). Associations between BMI and quality of life were determined by means of multivariate analyses.

RESULTS

322 women diagnosed with endometrioid endometrial cancer were invited to participate. Excluded were 15 women with unknown BMI, 40 with non-endometrioid histology and 10 with concurrent cancer. The QLQ-C30 questionnaire was completed by 158 (61.5%) women, of which 63 women (40%) were obese (BMI ≥ 30-39.9), and 30 women (19%) were morbidly obese (BMI ≥ 40). Morbidly obese women reported worse physical, role and social functioning and more somatic complaints.

CONCLUSION

Morbid obesity is associated with poorer quality of life in endometrial cancer survivors. Life style interventions such as exercise programs and diet interventions could be viable means to improve the quality of life of obese endometrial cancer survivors. Future research should focus on means to improve quality of life in obese endometrial cancer survivors.

Should visceral fat be reduced to increase longevity?

Several epidemiologic studies have implicated visceral fat as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and death. Utilizing novel models of visceral obesity, numerous studies have demonstrated that the relationship between visceral fat and longevity is causal while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. Specific recommended intake levels vary based on a number of factors, including current weight, activity levels, and weight loss goals. It is discussed the need of reducing the visceral fat as a potential treatment strategy to prevent or delay age-related diseases and to increase longevity.

A twenty-first century cancer epidemic caused by obesity: the involvement of insulin, diabetes, and insulin-like growth factors

Obesity has reached epidemic proportions in the developed world. The progression from obesity to diabetes mellitus type 2, via metabolic syndrome, is recognised, and the significant associated increase in the risk of major human cancers acknowledged. We review the molecular basis of the involvement of morbidly high concentrations of endogenous or therapeutic insulin and of insulin-like growth factors in the progression from obesity to diabetes and finally to cancer. Epidemiological and biochemical studies establish the role of insulin and hyperinsulinaemia in cancer risk and progression. Insulin-like growth factors, IGF-1 and IGF-2, secreted by visceral or mammary adipose tissue have significant paracrine and endocrine effects. These effects can be exacerbated by increased steroid hormone production. Structural studies elucidate how each of the three ligands, insulin, IGF-1, and IGF-2, interacts differently with isoforms A and B of the insulin receptor and with type I IGF receptor and explain how these protagonists contribute to diabetes-associated cancer. The above should inform appropriate treatment of cancers that arise in obese individuals and in those with diabetes mellitus type 2. Novel drugs that target the insulin and insulin-like growth factor signal transduction pathways are in clinical trial and should be effective if appropriate biomarker-informed patient stratification is implemented.

Should visceral fat, strictly linked to hepatic steatosis, be depleted to improve survival?

Numerous epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and its further expression, i.e., nonalcoholic fatty liver disease and death. Using novel models of visceral obesity, several studies have demonstrated that the relationship between visceral fat and longevity is causal, while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. The need of reducing the visceral fat to improve survival, mainly taking into account the strict link between nonalcoholic fatty liver disease and the coronary artery disease is discussed.

Body mass index, physical activity, and survival after endometrial cancer diagnosis: results from the Women's Health Initiative

OBJECTIVE

While low physical activity and high body mass index (BMI) have been associated with higher endometrial cancer incidence, no previous studies have evaluated the association between physical activity and survival after endometrial cancer diagnosis, and studies on BMI and survival have not been performed in a prospective cohort.

METHODS

We examined pre-diagnosis BMI and moderate- to vigorous-intensity physical activity in relation to overall and disease-specific survival among 983 postmenopausal women who were diagnosed with endometrial cancer in the Women's Health Initiative Observational Study and Clinical Trials.

RESULTS

Over a median 5.2 (max 14.1) years from diagnosis to death or end of follow-up, 163 total deaths were observed, 66 of which were due to endometrial cancer. We observed a higher all-cause mortality hazard ratio (HR) = 1.85 (95% CI 1.19-2.88) comparing women with a BMI ≥ 35 kg/m(2) to women with BMI< 25 kg/m(2). For endometrial cancer-specific mortality the HR = 2.23 (95% CI 1.09-4.54) comparing extreme BMI categories. To examine histologic subtypes we analyzed type I endometrial tumors separately and found an HR = 1.20 (95% CI 1.07-1.35) associated with all-cause mortality for each 5-unit change in BMI. Moderate- to vigorous-intensity physical activity was not associated with all-cause or endometrial cancer-specific mortality.

CONCLUSIONS

Pre-diagnosis BMI, but not physical activity, was associated with survival among women with endometrial cancer. Future studies should investigate mechanisms and timing of BMI onset to better understand the burden of disease attributable to BMI.

Prediagnosis body mass index, physical activity, and mortality in endometrial cancer patients

Background Higher body mass index (BMI) and inactivity have been associated with a higher risk of developing endometrial cancer, but the impact on endometrial cancer survival is unclear. Methods Among incident endometrial cancer case subjects in the National Institutes of Health-AARP Diet and Health Study, we examined associations of prediagnosis BMI (n = 1400) and physical activity (n = 875) with overall and disease-specific 5- and 10-year mortality. Using Cox proportional hazards regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for tumor characteristics, treatment, and other risk factors. All statistical tests were two-sided. Results Compared with women with a BMI in the range of 18.5 to less than 25kg/m(2), the hazard ratios for 5-year all-cause mortality were 1.74 (95% CI = 1.13 to 2.66) for BMI in the range of 25 to less than 30kg/m(2), 1.84 (95% CI = 1.17 to 2.88) for BMI in the range of 30 to less than 35kg/m(2), and 2.35 (95% CI = 1.48 to 3.73) for BMI greater than or equal to 35kg/m(2) (P trend < .001). Higher BMI was also statistically significantly associated with poorer endometrial cancer-specific but not cardiovascular disease 5-year mortality. Hazard ratio estimates for 10-year all-cause and endometrial cancer-specific mortality as related to BMI were similar to 5-year hazard ratio estimates, whereas 10-year cardiovascular disease mortality became statistically significant (HR = 4.08; 95% CI = 1.56 to 10.71 comparing extreme BMI groups). More physical activity was related to lower all-cause 5-year mortality (HR = 0.57, 95% CI = 0.33 to 0.98 for >7 hours/week vs never/rarely), but the association was attenuated after adjustment for BMI (HR = 0.64, 95% CI = 0.37 to 1.12). No association was observed between physical activity and disease-specific mortality. Conclusions Our findings suggest that higher prediagnosis BMI increases risk of overall and disease-specific mortality among women diagnosed with endometrial cancer, whereas physical activity lowers risk. Intervention studies of the effect of these modifiable lifestyle factors on mortality are needed.

Comorbidities and endometrial cancer survival in Hispanics and non-Hispanic whites

PURPOSE

We investigated comorbidities and endometrial cancer survival by ethnicity because Hispanic whites (HWs) have worse survival than non-Hispanic whites (NHWs).

METHODS

An endometrial cancer cohort (1992-2004) established with the Surveillance, Epidemiology and End Results-Medicare-linked database (n = 3,286) was followed through 2007. Endometrial cancer-specific and other cause mortality were evaluated with multivariate hazard ratios (mHRs).

RESULTS

HWs were more likely than NHWs to have regional/distant disease (31.7 vs. 24.8 %), diabetes (31.7 vs. 11.0 %), and hypertension (49.4 vs. 37.6 %). HWs had poorer endometrial cancer-specific survival than NHWs (age-adjusted HR = 1.28; 95% CI 1.01-1.61), but not after adjustment for tumor characteristics and treatment (mHR = 1.02; 95% CI 0.81-1.29). In contrast, even after adjustment for cancer-related factors, other cause mortality in HWs was elevated (mHR = 1.27; 95% CI 1.01-1.59), but not after further adjustment for comorbid conditions (mHR = 1.07; 95% CI 0.85-1.35).

CONCLUSIONS

Comorbidities, particularly diabetes, were more common in HWs than in NHWs and impacted other cause mortality. Improving diabetes management may be an effective means of improving other cause mortality. This may be particularly true for HWs, given their particularly high prevalence of diabetes.

Disease-specific mortality among stage I-III colorectal cancer patients with diabetes: a large population-based analysis

AIMS/HYPOTHESIS

The aim of our study was to investigate overall and disease-specific mortality of colorectal cancer patients with diabetes.

METHODS

In this population-based study, we included all colorectal cancer patients, newly diagnosed with stage I-III cancer, between 1997 and 2007 in the registration area of the Eindhoven Cancer Registry. Stage of cancer, cancer treatment and comorbidities were actively collected by reviewing hospital medical records. Data on patients with and without diabetes were linked to Statistics Netherlands to assess vitality, date of death and underlying cause of death. Follow-up of all patients was completed until 1 January 2009.

RESULTS

We included 6,974 patients with colon cancer and 3,888 patients with rectal cancer, of whom 820 (12%) and 404 (10%), respectively, had diabetes at the time of cancer diagnosis. During follow-up, death occurred in 611 (50%) of 1,224 cancer patients with diabetes and 3,817 (40%) of 9,638 cancer patients without diabetes. Multivariate Cox regression analyses, adjusted for age, sex, socioeconomic status, stage, lymph nodes examined, adjuvant therapy and year of diagnosis, showed that overall mortality was significantly higher for colon (HR 1.12, 95% CI 1.01, 1.25) and rectal (HR 1.21, 95% CI 1.03, 1.41) cancer patients with diabetes than for those without. Disease-specific mortality was only significantly increased for rectal cancer patients (HR 1.30, 95% CI 1.06, 1.60).

CONCLUSIONS/INTERPRETATION

Diabetes at the time of rectal cancer diagnosis was independently associated with an increased risk of colorectal cancer mortality compared with no diabetes, suggesting a specific interaction between diabetes and rectal cancer. Future in-depth studies including detailed diabetes- and cancer-related variables should elucidate pathways.

Obesity and endometrial cancer survival: a systematic review

Although it is known that obesity increases the risk of endometrial cancer and is linked to higher mortality rates in the general population, the association between obesity and mortality among endometrial cancer survivors is unclear. We performed a medline search using exploded Mesh keywords 'endometrial neoplasms/' and ('body mass index/' or 'obesity/') and ('survival analysis/' or 'mortality/' or (survivor* or survival*).mp.). We also inspected bibliographies of relevant papers to identify related publications. Our search criteria yielded 74 studies, 12 of which met inclusion criteria. Four of the included studies reported a statistically or marginally significant association between obesity and higher all cause mortality among endometrial cancer survivors after multivariate adjustment. The suggestive association between body mass index and higher all cause mortality among women with endometrial cancer was comparable to the magnitude of association reported in prospective studies of healthy women. Of the five studies that examined progression-free survival and the two studies reporting on disease-specific mortality, none reported an association with obesity. Future studies are needed to understand disease-specific mortality, the importance of obesity-onset timing and whether mechanisms of obesity-related mortality in this population of women differ from those of the general population.

The impact of race and comorbidity on survival in endometrial cancer

BACKGROUND

Poorer survival from endometrial cancer in blacks than in whites is well documented. The aims of this study were to determine whether diabetes, hypertension, or other conditions influence survival and whether accounting for these conditions reduces this racial disparity.

METHODS

Using the SEER-Medicare database, we investigated the influence of diabetes, hypertension, and other comorbid conditions on survival in black and white women age ≥66 with endometrial cancer. We used Cox proportional hazards regression to evaluate the influence of comorbidities on survival for blacks and whites separately and to study survival differences between blacks and whites after adjustment for diabetes, hypertension, and other medical conditions, as well as for demographics, tumor characteristics, and treatment.

RESULTS

In both racial subgroups, women with diabetes or other conditions had poorer overall survival, whereas hypertensive black women experienced better survival [HR, 0.74; 95% confidence interval (CI), 0.60-0.92]. For disease-specific survival, diabetes was associated with poorer survival in white women (HR, 1.19; 95% CI, 1.06-1.35) but not in blacks (HR, 0.97; 95% CI, 0.73-1.30); hypertension and other conditions were not significantly related to survival. After adjustment, black women had poorer survival than white women, with HRs of 1.16 (95% CI, 1.05-1.28) for overall and 1.27 (95% CI, 1.08-1.49) for disease-specific survival.

CONCLUSIONS

Diabetes influences disease-specific survival in white women but not in blacks. The racial disparity in survival is not explained by the presence of other health conditions.

IMPACT

Further research should focus on the unknown factors that lead to poorer survival in black women compared with whites.

Insulin resistance: a significant risk factor of endometrial cancer

OBJECTIVE

To review the role played by insulin resistance in the development of endometrial cancer.

METHODS

Relevant manuscripts and studies were searched on Medline using the terms endometrial cancer, insulin resistance, obesity, adipokine, C-peptide, leptin, adiponectin, plasminogen activator inhibitor-1, insulin, PI3K/Akt, Ras/MAPK and metformin alone or in combination.

RESULTS

Epidemiological studies have shown that insulin resistance is an important potential risk factor of endometrial cancer, and several research studies have been undertaken to determine the mechanism underlying its link to this malignant disease. Risk factors of insulin resistance, such as the inflammatory mediators, adipokines adiponectin, leptin and plasminogen activator inhibitor-1 and excessive androgen are also risk factors of endometrial cancer. High levels of insulin induced by insulin resistance have been found to exert direct and indirect effects that contribute to the development of endometrial cancer. Insulin directly promotes cell proliferation and survival through the PI3K/Akt and Ras/MAPK pathways. Moreover, the network among insulin, estrogen and insulin-like growth factor-1 also contributes to the development of endometrial cancer. Indirectly, insulin leads to changes in sex hormone levels, including increases in the levels of estrogen. Additionally, a small number of studies suggested that metformin, an insulin-sensitizing agent, has therapeutic potential for endometrial cancer.

CONCLUSIONS

This evidence suggests that insulin resistance plays a central role in endometrial cancer development. Understanding the relationship between insulin resistance and endometrial cancer may supply new ideas to fight this malignancy. Furthermore, combating insulin resistance may be a useful preventive and therapeutic strategy for endometrial cancer.

Metformin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and modulation of the mTOR pathway

OBJECTIVES

To examine the effects of combination therapy with metformin and paclitaxel in endometrial cancer cell lines.

METHODS

ECC-1 and Ishikawa endometrial cancer cell lines were used. Cell proliferation was assessed after exposure to paclitaxel and metformin. Cell cycle progression was assessed by flow cytometry. hTERT expression was determined by real-time RT-PCR. Western immunoblotting was performed to determine the effect of metformin/paclitaxel on the mTOR pathway.

RESULTS

Paclitaxel inhibited proliferation in a dose-dependent manner in both cell lines with IC(50) values of 1-5nM and 5-10nM for Ishikawa and ECC-1 cells, respectively. Simultaneous exposure of cells to various doses of paclitaxel in combination with metformin (0.5mM) resulted in a significant synergistic anti-proliferative effect in both cell lines (Combination Index<1). Metformin induced G1 arrest in both cell lines. Paclitaxel alone or in combination with metformin resulted in predominantly G2 arrest. Metformin decreased hTERT mRNA expression while paclitaxel alone had no effect on telomerase activity. Metformin stimulated AMPK phosphorylation and decreased phosphorylation of the S6 protein. In contrast, paclitaxel inhibited AMPK phosphorylation in the ECC-1 cell line and induced phosphorylation of S6 in both cell lines. Treatment with metformin and paclitaxel resulted in decreased phosphorylation of S6 in both cell lines but only had an additive effect on AMPK phosphorylation in the ECC-1 cell line.

CONCLUSIONS

Metformin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and modulation of the mTOR pathway. This combination may be a promising targeted therapy for endometrial cancer.

AMG 479, a novel IGF-1-R antibody, inhibits endometrial cancer cell proliferation through disruption of the PI3K/Akt and MAPK pathways

Our goal was to evaluate the therapeutic potential of a novel antibody to the insulin growth factor-1 receptor (IGF-1-R; AMG 479) in endometrial cancer cells. The endometrial cancer cell lines, ECC-1/PRAB72 and RL-95-2, were used. Treatment with AMG 479 (0.02-200 nmol/L) resulted in inhibition of cell proliferation at 72 to 120 hours. Insulin growth factor-1 (0.15-7.5 nmol/L) stimulated growth in both cell lines (range of 15%-42%, P = .0025-.0445), which could be blocked by pretreatment with AMG 479 (mean of 29% for ECC-1/PRAB72, P = .006-.007; mean of 36% for RL-95-2, P = .0002-.0045). AMG 479 suppressed IGF-1-R kinase activity in a dose-dependent manner. Cells treated with AMG 479 underwent either G1 (ECC-1/PRAB72) or G2 (RL-95-2) arrest. AMG 479 decreased human telomerase reverse transcriptase (hTERT) mRNA expression in both endometrial cancer cell lines. Treatment with AMG 479 rapidly blocked IGF-1-induced phosphorylation of IFG-1-R, Akt, and p44/42. Thus, manipulation of the IGF-1-R pathway may serve as a promising therapeutic strategy for the treatment of endometrial cancer.

[Characteristics of endometrial carcinoma in obese women]

INTRODUCTION

In most developed countries, endometrial cancer appears as most frequent invasive neoplasm of genital tract. Obesity is one of most important risk factors. Aim of study was to establish characteristics endometrial cancer in obese women.

MATERIAL AND METHODS

The study included 50 surgically treated women with endometrial cancer. According body mass index they were divided into two groups--group A (30 obese women), group B (20 non-obese women).

RESULTS AND DISCUSSION

Non-obese women with endometrial cancer are statistically significantly older than obese. Menopausal status, parity are not statistically significant. The obese group most frequently includes endometrioid type of tumor, while non-obese group most frequently includes non-endometrioid types of endometrial cancer. Over 50% thick myometrial invasion is statistically more frequent in non-obese group than in obese group. In obese group, less than 50% thick myometrial invasion, is statistically significant in comparison to nonobese group. High-differentiated endometrial cancer (G1) is statistically significantly more present in obese women than non-obese. Low-differentiated endometrial cancer is statistically more frequent in non-obese women than in obese. Most frequent in both groups is NG2. According to FIGO stage I, disease is statistically significantly more frequent in obese group than in non-obese. In non-obese group, total number of diseased in higher stages (II and III) is statistically significantly higher than in stage I.

CONCLUSION

Endometrial cancer present in obese women is mostly endometroid type I, with slow myometrial invasion, with histological grade I, nuclear grade II in FIGO stage I of disease. In non-obese women, non-endometrioid cancer-- type II is more frequent, with faster myometrial invasion, histological grade II and III, nuclear grade II, in FIGO stage II of disease.

Endometrial cancer, types, prognosis, female hormones and antihormones

Endometrial cancer covers several different types, the most prevalent in the developed world being endometrioid adenocarcinoma, which is estrogen-dependent and has a better prognosis compared to the non-estrogen-dependent types, e.g. papillary serous adenocarcinoma and clear cell carcinomas. Prognosis is also dependent on tumor differentiation and stage, and treatment should be adjusted accordingly. In this paper, the different types of endometrial cancer, staging, prognosis, diagnosis, prevention, treatment and their relationship to estrogen and other female hormones are reviewed.

Adipokines as novel biomarkers and regulators of the metabolic syndrome

Over the past two decades our view of adipose tissue has undergone a dramatic change from an inert energy storage tissue to an active endocrine organ. Adipose tissue communicates with other central and peripheral organs by synthesis and secretion of a host of molecules that we generally refer to as adipokines. The levels of some adipokines correlate with specific metabolic states and have the potential to impact directly upon the metabolic homeostasis of the system. A dysregulation of adipokines has been implicated in obesity, type 2 diabetes, hypertension, cardiovascular disease, and an ever-growing larger list of pathological changes in a number of organs. Here, we review the recent progress regarding the synthesis, secretion, and physiological function of adipokines with perspectives on future directions and potential therapeutic goals.

Adipokines as novel biomarkers and regulators of the metabolic syndrome

Over the past two decades our view of adipose tissue has undergone a dramatic change from an inert energy storage tissue to an active endocrine organ. Adipose tissue communicates with other central and peripheral organs by synthesis and secretion of a host of molecules that we generally refer to as adipokines. The levels of some adipokines correlate with specific metabolic states and have the potential to impact directly upon the metabolic homeostasis of the system. A dysregulation of adipokines has been implicated in obesity, type 2 diabetes, hypertension, cardiovascular disease, and an ever-growing larger list of pathological changes in a number of organs. Here, we review the recent progress regarding the synthesis, secretion, and physiological function of adipokines with perspectives on future directions and potential therapeutic goals.

Prostate cancer cell proliferation and angiogenesis in different obese mice models

Obesity has been associated with increased incidence and aggressiveness of prostate cancer. Although controversial, several studies suggest that leptin could influence tumour cell growth and proliferation. The main goal of this study was to assess cellular growth of prostate adenocarcinoma cells in obese mice with different endogenous hormonal environments in what relates to leptin circulating levels and sensitivity. Four groups of mice (n = 6/group) were used, namely obese mice with congenital non-functioning leptin receptor OBR (db/db), obese mice with congenital leptin deficiency (ob/ob), mice with diet induced obesity (DIO) and normal weight C57BL/6J mice (control). All groups of mice were injected subcutaneously with 3.0 x 10(5) RM1 cells/500 microl PBS (murine prostate carcinoma androgen insensitive cells) and tumour growth and angiogenesis were evaluated 14 days after inoculation. The tumours induced in ob/ob and DIO mice were significantly larger (P < 0.001) while those induced in db/db mice were significantly smaller (P = 0.047), when compared with controls. Morphometric analysis revealed that mitotic index and Ki-67 positive nuclear density, both cell proliferation markers, were also significantly lower in the tumours of db/db mice (P < 0.001) when compared to controls. An inverse correlation was observed between leptin plasma levels and tumour weight (r = -0.642, P < 0.001), mitotic index (r = -0.646, P < 0.01) and Ki-67 positive nuclear density (r = -0.795, P < 0.001). These results suggest that high leptin concentrations are not favourable to RM1 cell growth and proliferation. On the contrary, high plasma leptin levels were associated with less cellular proliferation and angiogenesis in vivo.

The role of adipose tissue and adipokines in obesity-related inflammatory diseases

Obesity is an energy-rich condition associated with overnutrition, which impairs systemic metabolic homeostasis and elicits stress. It also activates an inflammatory process in metabolically active sites, such as white adipose tissue, liver, and immune cells. As consequence, increased circulating levels of proinflammatory cytokines, hormone-like molecules, and other inflammatory markers are induced. This determines a chronic active inflammatory condition, associated with the development of the obesity-related inflammatory diseases. This paper describes the role of adipose tissue and the biological effects of many adipokines in these diseases.

Insulin receptor substrate-2 gene polymorphism: is it associated with endometrial cancer?

OBJECTIVE

The G1057D polymorphism in the insulin receptor substrate-2 (IRS-2) gene has been reported to be associated with insulin resistance, obesity and type 2 diabetes. However little is known about its possible association with cancer. To investigate this association, we determined the distribution of its genotypes and frequency of alleles in endometrial cancer patients.

METHODS

The study population consisted of 184 subjects: 44 patients with endometrial cancer and 140 controls without cancer. All the patients were primarily treated with surgical intervention. DNA was extracted from the leucocytes by high pure polymerase chain reaction (PCR) template preparation kit. Genetic polymorphism of IRS-2 G1057D was detected by using PCR-based restriction fragment-length polymorphism.

RESULTS

For IRS-2 G1057D polymorphism, there was a significant difference in genotype distribution and allele frequency between endometrial cancer patients and controls (p < 0.001). The risk for endometrial cancer was 4.87 times higher in the individuals with the IRS-2 DD genotype compared to the GG genotype [95% confidence interval (CI): 1.74-13.63 p = 0.003]. Also individuals with the IRS-2 D allele had a significantly higher risk of endometrium cancer compared with individuals with the IRS-2 G allele, with a relative risk of 2.23 (95% CI: 1.36-3.67, p = 0.001) for cases compared with population controls.

CONCLUSION

These results suggest that IRS-2 G1057D polymorphism may be associated with endometrial cancer.

Metformin is a potent inhibitor of endometrial cancer cell proliferation--implications for a novel treatment strategy

OBJECTIVES

Obesity and diabetes are strong risk factors that drive the development of type I endometrial cancers. Recent epidemiological evidence suggests that metformin may lower cancer risk and reduce rates of cancer deaths among diabetic patients. In order to better understand metformin's anti-tumorigenic potential, our goal was to assess the effect of metformin on proliferation and expression of key targets of metformin cell signaling in endometrial cancer cell lines.

METHODS

The endometrial cancer cell lines, ECC-1 and Ishikawa, were used. Cell proliferation was assessed after exposure to metformin. Cell cycle progression was evaluated by flow cytometry. Apoptosis was assessed by ELISA for caspase-3 activity. hTERT expression was determined by real-time RT-PCR. Western immunoblotting was performed to determine the expression of the downstream targets of metformin.

RESULTS

Metformin potently inhibited growth in a dose-dependent manner in both cell lines (IC(50) of 1 mM). Treatment with metformin resulted in G1 arrest, induction of apoptosis and decreased hTERT expression. Western immunoblot analysis demonstrated that metformin induced phosphorylation of AMPK, its immediate downstream mediator, within 24 h of exposure. In parallel, treatment with metformin decreased phosphorylation of S6 protein, a key target of the mTOR pathway.

CONCLUSIONS

We find that metformin is a potent inhibitor of cell proliferation in endometrial cancer cell lines. This effect is partially mediated through AMPK activation and subsequent inhibition of the mTOR pathway. This work should provide the scientific foundation for future investigation of metformin as a strategy for endometrial cancer prevention and treatment.

Endometrial cancer and obesity: epidemiology, biomarkers, prevention and survivorship

Endometrial cancer is the most common gynecologic malignancy in the Western world and is strongly associated with obesity. Despite the fact that most cases are diagnosed in early, more favorable stages, endometrial cancer incidence and mortality rates are on the rise. Morbidly obese women with endometrial cancer are more likely to die of their co-morbidities and also of their cancers when compared to their leaner cohorts. Given the increasing rates of morbid obesity in the United States, it is essential to develop appropriate screening tools and guidelines to reduce cancer morbidity and death amongst this group. Through an analysis of the existing literature, we present a review of the epidemiologic trends in obesity and endometrial cancer, discuss the promising role of screening biomarker studies, review prevention efforts and modifiable risk factors, and ways in which health outcomes and quality of life for endometrial cancer survivors may be optimized.

Association of diabetes with survival among cohorts of Indigenous and non-Indigenous Australians with cancer

BACKGROUND

The association between diabetes and cancer incidence has been well documented, but relatively little research has been undertaken on the potential influence of diabetes on cancer survival and the research that is available has produced inconsistent results. Because Indigenous Australians have a high prevalence of diabetes, we assessed survival, stratified by diabetes, among Indigenous Australian cancer patients. We also assessed survival, stratified by diabetes, amongst a cohort of non-Indigenous Australian cancer patients.

METHODS

All-cause survival and cancer-specific survival in diabetic versus non-diabetic cancer patients were assessed in Indigenous and non-Indigenous cohorts separately, using proportional hazards models.

FINDINGS

Indigenous cancer patients with diabetes (n = 140) had an overall survival disadvantage compared to Indigenous cancer patients without diabetes (n = 675) with all-cause Hazard Ratio (HR) = 1.4 (95% CI 1.1-1.8) adjusted for age, sex, and cancer site. After further adjustment to take into account the greater number of non-cancer deaths and co-morbidities in Indigenous cancer patients with diabetes, and their later stage at cancer diagnosis with less cancer treatment, there was no residual difference in cancer-specific survival compared to Indigenous cancer patients without diabetes (cancer-specific HR = 1.0, 95% CI 0.8, 1.3). Fewer non-Indigenous cancer patients had diabetes (n = 52) and they showed no differences in survival compared to their counterparts without diabetes.

INTERPRETATION

The poorer survival of Indigenous Australian cancer patients with diabetes was due to more non-cancer deaths, later stage at cancer diagnosis, less cancer treatment, and more co-morbidities than Indigenous Australian cancer patients without diabetes. In contrast, diabetes did not appear to affect survival in non-Indigenous Australians with cancer, either because there were too few to detect a moderate deleterious effect or because there was no association. Understanding the relation between diabetes and cancer treatment and survival is important because both diabetes and cancer are relatively common diseases, increasingly likely to co-exist.

Glucose metabolism disorders in cancer patients in a Chinese population

BACKGROUND

Characteristics of glucose metabolism disorders (GMDs) in different cancers and the contributory role of GMDs in developing cancers are still not so clear.

METHODS

Two thousand four hundred and five patients with malignancy who had been hospitalized in the First Affiliated Hospital of Jinan University were pooled as case group. Two thousand and sixteen non-cancer people who finished health examinations in the Affiliated Yangcheng Hospital of Guangzhou Medical College were enrolled as control group. We compared glucose metabolism among patients with different kinds of malignancy. Based on logistic regression models, we analyzed factors that affect the development of carcinoma.

RESULTS

(1) Among 2,408 malignancy patients, the total prevalence of diabetes mellitus (DM) and impaired fasting glucose (IFG) reached 28.0%. Pancreatic cancer, lymphoma, liver cancer, leukemia, and colorectal cancer showed most striking hyperglycemia. (2) Leukemia and esophageal cancer accounting for 12.5% and 12.1%, respectively, were the most likely to suffer from hypoglycemia. (3) Older cancer patients seem to be more vulnerable to hyperglycemia, while the younger tend to be more likely to develop hypoglycemia. (4) High level of fasting plasma glucose (FPG) was associated with lung cancer, breast cancer, leukemia, lymphoma, thyroid cancer, bladder cancer, and pancreatic cancer. Patients with DM increased risks for developing colorectal cancer, liver cancer, esophageal cancer, thyroid cancer, cervical cancer, and pancreatic cancer.

CONCLUSIONS

GMDs are frequent events in malignancy patients. Hyperglycemia and hypoglycemia are found in the same kinds or different kinds of cancers, and the incidence of hyperglycemia is higher than that of hypoglycemia. Characteristics of GMDs were dissimilar in different cancers and different ages. Hyperglycemia was a risk factor for many cancers.

Factors influencing endometrial cancer mortality: the Western Pennsylvania Registry

BACKGROUND

Endometrial carcinoma is the most common cancer of the lower female genital tract in the USA. Various factors, including age, body mass index, race, disease stage, diabetes, histology, tumor grade and other comorbid conditions were associated with endometrial carcinoma mortality in previous case-control and cross-sectional studies not involving tumor registries. Cancer registries are important sources of data on endometrial cancer; however, they are rarely utilized in current research projects. The purpose of this study was to analyze factors associated with endometrial cancer mortality in the University of Pittsburgh Medical Center (UPMC) Magee Cancer Registry (PA, USA).

METHODS

Data were obtained from the UPMC cancer registry from 1996 to 2007. A total of 1614 cases were identified using the Honest Broker system at Magee Womens Hospital. Key factors involved in endometrial cancer mortality were identified through survival analysis.

RESULTS

Among the characteristics available from the cancer registry, the following were the main ones associated with endometrial cancer mortality: race, stage, chemotherapy, parity and lymph node involvement.

CONCLUSIONS

This is one of the first studies that reported factors influencing endometrial cancer mortality in patients residing in Pittsburgh area. An improved understanding of risk factors associated with endometrial cancer morbidity and mortality may hold a key to better preventive strategies for endometrial carcinoma, especially for women in high-risk groups.

Role of visceral adipose tissue in aging

BACKGROUND

Visceral fat (VF) accretion is a hallmark of aging in humans. Epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes, cardiovascular disease, metabolic syndrome and death.

METHODS

Studies utilizing novel rodent models of visceral obesity and surgical strategies in humans have been undertaken to determine if subcutaneous (SC) abdominal or VF are causally linked to age-related diseases.

RESULTS

Specific depletion or expansion of the VF depot using genetic or surgical tools in rodents has been shown to have direct effects on disease risk. In contrast, surgically removing large quantities of SC fat does not consistently improve metabolic parameters in humans or rodents, while benefits were observed with SC fat expansion in mice, suggesting that SC fat accrual is not an important contributor to metabolic decline. There is also compelling evidence in humans that abdominal obesity is a stronger risk factor for mortality risk than general obesity. Likewise, we have shown that surgical removal of VF improves mean and maximum lifespan in rats, providing the first causal evidence that VF depletion may be an important underlying cause of improved lifespan with caloric restriction.

GENERAL SIGNIFICANCE

This review provides both corollary and causal evidence for the importance of accounting for body fat distribution, and specifically VF, when assessing disease and mortality risk. Given the hazards of VF accumulation on health, treatment strategies aimed at selectively depleting VF should be considered as a viable tool to effectively reduce disease risk in humans.

Long-term all-cause mortality in cancer patients with preexisting diabetes mellitus: a systematic review and meta-analysis

CONTEXT

Diabetes mellitus appears to be a risk factor for some cancers, but the effect of preexisting diabetes on all-cause mortality in newly diagnosed cancer patients is less clear.

OBJECTIVE

To perform a systematic review and meta-analysis comparing overall survival in cancer patients with and without preexisting diabetes.

DATA SOURCES

We searched MEDLINE and EMBASE through May 15, 2008, including references of qualifying articles.

STUDY SELECTION

English-language, original investigations in humans with at least 3 months of follow-up were included. Titles, abstracts, and articles were reviewed by at least 2 independent readers. Of 7858 titles identified in our original search, 48 articles met our criteria.

DATA EXTRACTION

One reviewer performed a full abstraction and other reviewers verified accuracy. We contacted authors and obtained additional information for 3 articles with insufficient reported data.

RESULTS

Studies reporting cumulative survival rates were summarized qualitatively. Studies reporting Cox proportional hazard ratios (HRs) or Poisson relative risks were combined in a meta-analysis. A random-effects model meta-analysis of 23 articles showed that diabetes was associated with an increased mortality HR of 1.41 (95% confidence interval [CI], 1.28-1.55) compared with normoglycemic individuals across all cancer types. Subgroup analyses by type of cancer showed increased risk for cancers of the endometrium (HR, 1.76; 95% CI, 1.34-2.31), breast (HR, 1.61; 95% CI, 1.46-1.78), and colorectum (HR, 1.32; 95% CI, 1.24-1.41).

CONCLUSIONS

Patients diagnosed with cancer who have preexisting diabetes are at increased risk for long-term, all-cause mortality compared with those without diabetes.

Obesity and gynaecological cancer

Obesity is now considered to be a global epidemic. The problem of obesity has significant implications for the diagnosis and treatment of gynaecological cancer. The cancer most frequently associated with obesity is that of the endometrium. The risk of endometrial cancer is 2-3 times higher in overweight and obese women. Obesity also adversely affects survival in most studies. With regard to ovarian cancer the evidence is inconsistent. Obesity in young adulthood may be more important than that in later life. With regard to survival obesity has an adverse effect but not in early stage disease. Few data are available regarding cervical cancer and obesity. There is evidence that obesity is associated with adenocarcinoma rather than squamous carcinoma. Data on vulval cancer and obesity are scant.