Diabetes and endometrial cancer: an Italian case-control study

Risk factors for endometrial cancer in Black women

PURPOSE

The incidence of endometrial cancer (EC) has been increasing faster among Black women than among other racial/ethnic groups in the United States. Although the mortality rate is nearly twice as high among Black than White women, there is a paucity of literature on risk factors for EC among Black women, particularly regarding menopausal hormone use and severe obesity.

METHODS

We pooled questionnaire data on 811 EC cases and 3,124 controls from eight studies with data on self-identified Black women (4 case-control and 4 cohort studies). We analyzed cohort studies as nested case-control studies with up to 4 controls selected per case. We used logistic regression to estimate multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We observed a positive association between BMI and EC incidence (P_trend < 0.0001) The OR comparing BMI ≥ 40 vs. < 25 kg/m² was 3.92 (95% CI 2.91, 5.27). Abdominal obesity among those with BMI < 30 kg/m² was not appreciably associated with EC risk (OR 1.21, 95% CI 0.74, 1.99). Associations of reproductive history with EC were similar to those observed in studies of White women. Long-term use of estrogen-only menopausal hormones was associated with an increased risk of EC (≥ 5 years vs. never use: OR 2.08, 95% CI: 1.06, 4.06).

CONCLUSIONS

Our results suggest that the associations of established risk factors with EC are similar between Black and White women. Other explanations, such as differences in the prevalence of known risk factors or previously unidentified risk factors likely underlie the recent increases in EC incidence among Black women.

Trend changes and factor analysis of endometrial hyperplasia in patients with polycystic ovarian syndrome based on the Korean National Health Insurance Database

Background

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with an increased risk of other gynecological disorders, such as endometrial hyperplasia (EH). However, substantial factors in the comorbidity of EH and PCOS remain to be investigated. We analyzed trend changes in PCOS and factors related to the comorbidity of PCOS and EH using data from the Korea National Health Insurance (KNHI) claims database.

Methods

The data for this population-based study of people diagnosed with PCOS or EH in Korea from 2009 to 2016 were collected from the KNHI claims database between 2007 and 2017. We conducted a trend analysis of the prevalence and incidence of PCOS and EH. In addition, we performed a logistic regression analysis to identify risk factors associated with EH incidence in people with PCOS using the matched case-control methodology.

Results

The average annual growth rate of the incidence of PCOS was 14.1% from 2009 to 2016, whereas the EH rate increased by only 3.4% annually. Comorbidities, type 2 diabetes, obesity, hypertension, hyperlipidemia, and infertility, increased the risk of EH in PCOS patients. Additionally, the cumulative duration of oral contraceptive & progestin treatment for PCOS correlated highly with the comorbidity of EH and PCOS.

Conclusions

We confirmed the relationship between PCOS and EH using big data suitable for time series analyses of the diagnosis and treatment of diseases. Endometrial evaluation should be done with more caution if oral contraceptives & progestins have been used for a long time.

Endometrial Cancer in Reproductive Age: Fertility-Sparing Approach and Reproductive Outcomes

Endometrial cancer is the most common gynecologic malignancy in developed countries and approximately 7% of the women with endometrial cancer are below the age of 45. Management of endometrial cancer in young women who desire to maintain fertility presents a unique set of challenges since the standard surgical treatment based on hysterectomy and salpingo-oophorectomy is often not compatible with the patient's goals. A fertility-preserving approach can be considered in selected patients with early stage and low-grade endometrial cancer. An increasing amount of data suggest that oncologic outcomes are not compromised if a conservative approach is utilized with close monitoring until childbearing is completed. If a fertility-preserving approach is not possible, assisted reproductive technologies can assist patients in achieving their fertility goals.

The effect of diabetes on the risk of endometrial Cancer: an updated a systematic review and meta-analysis

Background

Previous studies conducted on the association between diabetes and the risk of endometrial cancer have reported controversial results that have raised a variety of questions about the association between diabetes and the incidence of this cancer. Thus, the aim of this systematic review and meta-analysis was to more precisely estimate the effect of diabetes on the risk of endometrial cancer incidence.

Methods

All original articles were searched in international databases, including Medline (PubMed), Web of sciences, Scopus, EMBASE, and CINHAL. Search was done from January 1990 to January 2018 without language limitations. Also, logarithm and standard error logarithm relative risk (RR) were used for meta-analysis.

Results

A total of 22 cohort and case-control studies were included in this meta-analysis, of which 14 showed statistically significant associations between diabetes and risk of endometrial cancer. Diabetes was associated with increased risk of endometrial cancer (RR = 1.72, 95% CI 1.48–2.01). The summary of RR for all 9 cohort studies was 1.56 (95% CI 1.21–2.01), and it was 1.85 (95% CI 1.53–2.23) for 13 case control studies. The summary of RR in hospital-based studies was higher than other studies. Thirteen of the primary studies-controlled BMI as a confounding variable, and the combined risk of their results was 1.62 (95% CI 1.34–1.97).

Conclusions

Diabetes seems to increases the risk of endometrial cancer in women, and this finding can be useful in developing endometrial cancer prevention plans for women having diabetes.

Metformin, other antidiabetic drugs, and endometrial cancer risk: a nested case-control study within Italian healthcare utilization databases

Metformin may reduce the risk of endometrial cancer whereas other drugs for the treatment of type 2 diabetes mellitus appear to increase it, although the evidence is still limited. We investigated this issue using data from a nested case-control study within the healthcare utilization databases of the Lombardy Region, Italy. This study included 376 diabetic women with endometrial cancer and 7485 diabetic controls matched for cases on age, date at cohort entry, and duration of follow-up. We used conditional logistic regression models to estimate the odds ratio (OR) of endometrial cancer in relation to use of antidiabetic drugs, adjusted for the Charlson's comorbidity index, selected medical conditions, prescription of selected drugs, and concomitant use of other antidiabetic drugs. At cohort entry, no significant associations were observed for metformin [OR=0.99, 95% confidence interval (CI) 0.80-1.23], sulfonylureas (OR=1.14, 95% CI 0.91-1.42), insulin (OR=0.72, 95% CI 0.34-1.56), and other antidiabetic drugs (OR=1.21, 95% CI 0.75-1.95). When we considered use during follow-up, a borderline significant excess risk was found for metformin (OR=1.30, 95% CI 1.00-1.70). However, this estimate decreased to 1.07 (95% CI 0.82-1.41) when taking into account BMI using a Monte Carlo sensitivity analysis. No significant associations were found for sulfonylureas (OR=1.16, 95% CI 0.91-1.47), thiazolidinediones (OR=0.77, 95% CI 0.48-1.24), repaglinide (OR=1.32, 95% CI 0.94-1.87), incretins (OR=1.21, 95% CI 0.63-2.32), and insulin (OR=1.19, 95% CI 0.82-1.71). Our data indicate that metformin, insulin, and other antidiabetic drugs did not meaningfully affect the risk of endometrial cancer.

Association of endometrial hyperplasia and cancer with a history of gestational diabetes

PURPOSE

Excess circulating insulin may contribute to endometrial cancer (EC) development; studies suggest increased risk of EC associated with type 2 diabetes. We investigated whether gestational diabetes is associated with increased risk of EC and its precursor, endometrial hyperplasia (EH).

METHODS

We conducted a population-based, case-control study of women in Washington State. Cases were women with a hospital discharge record indicating the presence of EH/EC who could be linked to a prior delivery hospitalization or birth record from 1987 to 2013 (n = 593). Controls were randomly selected from remaining deliveries, frequency matched 10:1 on delivery year and maternal age at delivery (n = 5,743). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

After adjustment for race/ethnicity, maternal age at delivery, and delivery year, EH/EC was associated with a history of gestational diabetes (OR 1.73, 95% CI 1.27-2.35). This association was present for both EH and EC (OR 1.61, 95% CI 1.00-2.60 and OR 1.80, 95% CI 1.22-2.65, respectively). After adjustment for prepregnancy body mass index, the OR for EH/EC was attenuated and became statistically non-significant (OR 1.22, 95% CI 0.87-1.72), except in women <50 years old at the time of case ascertainment (OR 1.49, 95% CI 1.00-2.20). Associations were slightly stronger for EC than EH.

CONCLUSIONS

We observed an association between EH/EC and a history of gestational diabetes specific to younger women. Future studies focusing on the relationships between gestational diabetes, obesity, and EC, including age at diagnosis, are warranted.

Improving survival after endometrial cancer: the big picture

To improve survival in women with endometrial cancer, we need to look at the "big picture" beyond initial treatment. Although the majority of women will be diagnosed with early stage disease and are cured with surgery alone, there is a subgroup of women with advanced and high-risk early stage disease whose life expectancy may be prolonged with the addition of chemotherapy. Immunohistochemistry will help to identify those women with Lynch syndrome who will benefit from more frequent colorectal cancer surveillance and genetic counseling. If they happen to be diagnosed with colorectal cancer, this information has an important therapeutic implication. And finally, because the majority of women will survive their diagnosis of endometrial cancer, they remain at risk for breast and colorectal cancer, so these women should be counselled about screening for these cancers. These three interventions will contribute to improving the overall survival of women with endometrial cancer.

Body Size, Metabolic Factors, and Risk of Endometrial Cancer in Black Women

Total and abdominal obesity, as well as metabolic factors such as type 2 diabetes, have been associated with a higher risk of endometrial cancer in white women. It remains unclear to what extent these factors influence the risk of endometrial cancer in black women. We followed 47,557 participants from the Black Women's Health Study for incident endometrial cancer from 1995 through 2013 (n = 274). We used Cox regression models to estimate incidence rate ratios and 95% confidence intervals while accounting for potential confounders. Incidence rate ratios for body mass indices (weight (kg)/height (m)(2)) of 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40.0 versus those <25.0 were 1.00 (95% confidence interval (CI): 0.67, 1.48), 1.49 (95% CI: 0.97, 2.30), 2.16 (95% CI: 1.34, 3.49), and 3.60 (95% CI: 2.24, 5.78), respectively (Ptrend <0.0001). A high weight-to-height ratio was also associated with a higher risk (for the highest quartile vs. the lowest, incidence rate ratio = 2.83, 95% CI: 1.77, 4.53), as was type 2 diabetes mellitus (incidence rate ratio = 1.52, 95% CI: 1.04, 2.21). Positive associations with measures of central adiposity (waist circumference, waist-to-hip ratio, and waist-to-height ratio) and hypertension were attenuated after we controlled for body mass index. Total adiposity was an independent risk factor for endometrial cancer among black women and appeared to explain most of the associations seen with other adiposity measures and metabolic factors.

A Population-Based Cohort Study of All-Cause and Site-Specific Cancer Incidence Among Patients With Type 1 Diabetes Mellitus in Taiwan

BACKGROUND

The relationship between type 1 diabetes mellitus (T1DM) and cancer incidence remains unclear. We sought to assess the all-cause and site-specific cancer incidence in patients with T1DM.

METHODS

A retrospective cohort study design was employed, in which 14 619 patients with T1DM were retrieved from Taiwan's National Health Insurance medical claims between 2000 and 2007. The study subjects were followed to the end of 2008, and cancer incidence was assessed. We calculated age-, sex-, and calendar year-standardized incidence ratios (SIRs) of all-cause cancer incidence and site-specific neoplasm incidence, with reference to the general population.

RESULTS

Seven hundred and sixty patients were identified for all-cause cancer over 86,610 person-years, representing an incidence rate of 87.75 cases per 10,000 person-years. The incidence rate was higher in males than in female patients (109.86 vs 69.75 cases per 10,000 person-years). T1DM was associated with a significantly increased SIR of all-cause cancer (1.13; 95% confidence interval [CI], 1.05-1.22). The sex-specific SIR was significantly elevated in female patients (1.19; 95% CI, 1.07-1.33), but the SIR for male patients was insignificantly elevated (1.09; 95% CI, 0.99-1.20). Pancreatic cancer showed the greatest increase in SIR among both male and female patients with T1DM. Male patients experienced significantly increased SIRs for kidney, rectum, liver, and colon neoplasm, and significantly increased SIRs were noted for ovarian, bladder, and colon cancer in female patients.

CONCLUSIONS

T1DM was associated with a 13% increase in risk of all-cause cancer incidence. Patients with T1DM should be advised to undergo cancer screening for certain types of cancer.

Circulating adropin levels in patients with endometrium cancer

AIM

Adropin is a recently identified protein in liver, brain and many peripheral tissues, which is important in energy homeostasis. The purpose of this study is to determine adropin levels in patients with endometrium cancer (EC).

MATERIAL AND METHODS

A total of 74 patients (47 EC patients and 27 healthy controls) were included in the study. Fasting venous blood samples were collected from all patients. Serum adropin levels were measured by an enzyme-linked immunosorbent assay (ELISA). The correlations between serum adropin levels and clinicopathologic variables were determined.

RESULTS

In body mass index and age-matched groups of patients, adropin levels were determined lower in patients with EC than control group (p < 0.01). Adropin levels were negatively correlated with age (r = -0.265, p = 0.023), homeostasis model-resistance index (HOMA-IR) (r = -0.294, p = 0.005) and fasting insulin levels (r = -0.292, p = 0.001). It was shown that in receiver operator characteristic (ROC) analysis, at cut-off value ≤ 1.055 (ng/ml), adropin had 92.7% sensitivity, 91.5% specificity and had AUC = 0.948, CI; 0.894-1.000 for diagnosis of EC (p < 0.001).

CONCLUSION

Adropin seems to be an important protein in pathogenesis of EC. Clearly, there are largely unknown aspects of adropin in EC pathophysiology and require further multi-centered, molecular and genetic studies including high number of cases.

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.

Diabetes and cancer: two diseases with obesity as a common risk factor

There is a growing body of evidence to support a connection between diabetes (predominantly type 2), obesity and cancer. Multiple meta-analyses of epidemiological data show that people with diabetes are at increased risk of developing many different types of cancers, along with an increased risk of cancer mortality. Several pathophysiological mechanisms for this relationship have been postulated, including insulin resistance and hyperinsulinaemia, enhanced inflammatory processes, dysregulation of sex hormone production and hyperglycaemia. In addition to these potential mechanisms, a number of common risk factors, including obesity, may be behind the association between diabetes and cancer. Indeed, obesity is associated with an increased risk of cancer and diabetes. Abdominal adiposity has been shown to play a role in creating a systemic pro-inflammatory environment, which could result in the development of both diabetes and cancer. Here, we examine the relationship between diabetes, obesity and cancer, and investigate the potential underlying causes of increased cancer risk in individuals with diabetes. Current treatment recommendations for reducing the overall disease burden are also explored and possible areas for future research are considered.

Risks of Breast and Endometrial Cancer in Women with Diabetes: A Population-Based Cohort Study

Objective

We investigated the overall and age-specific risks of developing breast and endometrial cancer among women with diabetes in a population-based cohort study.

Methods

Women with diabetes (n = 319310) and age-matched controls (n = 319308), selected from ambulatory care claims and beneficiary registry in 2000, respectively were linked to the in-patient claims (2000–2008) to identify admissions due to breast (ICD-9-CM: 174) and endometrial (ICD-9-CM: 182) cancer. The person-year approach with Poisson assumption was used to estimate the incidence density rate. The age-specific hazard ratios (HRs) of above malignancies in relation to diabetes with multivariate Cox proportional hazard regression.

Results

The overall incidence density rate of breast and endometrial cancer was estimated at 1.21 and 0.21 per 10,000 patient-years, respectively, for diabetes. The corresponding figures for controls were lower at 1.00 and 0.14 per 10,000 patient-years. Compared with the controls, the covariate adjusted HR for breast and endometrial cancer was 1.42 (95% confidence interval (CI) 1.34–1.50) and 1.71 (95% CI 1.48–1.97), respectively in women with diabetes. Elderly (> = 65 years) diabetes had the highest HR (1.61) of breast cancer, while the highest HR (1.85) of endometrial cancer was observed in diabetes aged < = 50 years.

Conclusions

Diabetes may significantly increase the risks of breast and endometrial cancer in all age stratifications. Health education for strict adherence of cancer screening program in women with diabetes is essential.

Diabetes in women: a life-course approach

The increasing prevalence of diabetes in combination with an aging population and increasing female longevity means that it is important to understand the effects of diabetes on women's health. Both type 1 and type 2 diabetes influence health outcomes throughout the life-course. This review article provides a summary of sex differences in diabetes epidemiology and covers specific aspects of the life-course in women including: the menarche, pregnancy and the menopause. It also discusses the associations with other conditions: cardiovascular disease, osteoporosis and cancer.

Epidemiological evidence of a relationship between type-1 diabetes mellitus and cancer: a review of the existing literature

This review explores the epidemiological evidence relating to type-1 diabetes (T1DM) and cancer incidence and mortality. Mortality rates among those with T1DM are higher in every age group compared with the general population; the majority of this mortality is due to factors related to the consequences of diabetes, such as cardiovascular and renal disease. For over 100 years, researchers have explored the relationships between diabetes and cancer and although there is now a large body of work on the subject, consensus has not been reached. Such research has tended to focus upon type-2 diabetes, with the result that very little is known about T1DM and cancer. As incidence of T1DM increases, by around 3% annually among children, the need for further research into its impact upon cancer incidence and mortality increases. Within this review, findings varied by study method utilised, T1DM definition used and study region and outcome measure explored. None of the case-control studies found a statistically significant link between the two diseases, whereas both of the meta-analyses did. Cohort studies produced mixed results. There were also mixed findings among research that defined T1DM in the same way (e.g. defining individuals with the disease as those diagnosed with diabetes before 30 years of age). The review found a number of studies which explored cause-specific cancer mortality among those with diabetes; such studies also had mixed findings. This inconsistency within results suggests the need for further research to understand better the potential relationships between T1DM and cancer.

Diabetes and cancer I: risk, survival, and implications for screening

Type 2 diabetes mellitus (DM) and cancer are common diseases that are frequently diagnosed in the same individual. An association between the two conditions has long been postulated. Here, we review the epidemiological evidence for increased risk of cancer, decreased cancer survival, and decreased rates of cancer screening in diabetic patients. The risk for several cancers, including cancers of the pancreas, liver, colorectum, breast, urinary tract, and endometrium, is increased in patients with DM. In a pooled risk analysis weighting published meta-analytic relative risk (RR) for individual cancer by differences in their incidence rates, we found a population RR of 0.97 (95 % CI, 0.75-1.25) in men and 1.29 (95 % CI, 1.16-1.44) in women. All meta-analyses showed an increased relative risk for cancer in diabetic men, except studies of prostate cancer, in which a protective effect was observed. The relationship between diabetes and cancer appears to be complex, and at present, a clear temporal relationship between the two conditions cannot be defined. DM also impacts negatively on cancer-related survival outcomes and cancer screening rates. The overwhelming evidence for lower cancer screening rates, increased incidence of certain cancers, and poorer prognosis after cancer diagnosis in diabetic patients dictates a need for improved cancer care in diabetic individuals through improved screening measures, development of risk assessment tools, and consideration of cancer prevention strategies in diabetic patients. Part two of this review focuses on the biological and pharmacological mechanisms that may account for the association between DM and cancer.

High rates of endometrial cancer among Pacific women in New Zealand: the role of diabetes, physical inactivity, and obesity

PURPOSE

To determine the endometrial cancer rates, and the proportion attributable to diabetes mellitus (DM), physical inactivity, and overweight/obesity, by ethnicity with a focus on Pacific women in New Zealand.

METHODS

Linked census-cancer records (1981-2004) were used to determine incidence rates of endometrial cancer by ethnicity. Health survey data (2006-2007) were used to determine risk factor prevalence by ethnicity. Relative risks for the association between diabetes, obesity, physical inactivity and endometrial cancer were sourced from published studies. Population attributable risk (PAR) methods, with Monte Carlo simulation, were used to estimate the PAR% by ethnicity and applied to 2001-2004 cancer rates.

RESULTS

Pacific women had 2.61 (95 % confidence interval 2.22-3.05) times the endometrial cancer rate of European/Other women pooled over time, and the most rapidly increasing rates over time with the rate ratio increasing from 1.96 (1.14-3.37) in 1981/1986 to 3.78 (3.03-4.71) in 2001/2004 (p for trend = 0.14). Pacific women had the highest PAR% for DM, physical inactivity, and overweight/obesity (63.1 %), followed by Māori (58.6 %) and European/Other (48.6 %). Applying these PAR% to 2001-2004 endometrial cancer rates, the rate ratio comparing Pacific to European/Other endometrial cancer reduced from 3.8 for total cancer (attributable plus non-attributable) to 2.3 for non-attributable cancer, and the rate difference reduced by 79 % from 51 to 11 per 100,000.

CONCLUSIONS

Pacific women have high endometrial cancer rates in New Zealand. Some, but not all, of the ethnic inequalities were explained by measured differences in obesity/overweight, DM, and physical inactivity.

Understanding obesity and endometrial cancer risk: opportunities for prevention

Worldwide, obesity has become a major public health crisis. Overweight and obesity not only increase the risk of cardiovascular disease and type-2 diabetes mellitus but also are now known risk factors for a variety of cancer types. Among all cancers, increasing body mass index is associated most strongly with endometrial cancer incidence and death. The molecular mechanisms underlying how adipose tissue and obesity contribute to the pathogenesis of endometrial cancer are becoming better understood and have revealed a number of rational strategies, both behavioral and pharmaceutical, for the prevention of both primary and recurrent disease.

Cancer risk among patients hospitalized for Type 1 diabetes mellitus: a population-based cohort study in Sweden

AIMS

Type 1 diabetes mellitus (T1DM) is an autoimmune disease with potential mechanistic links to immune-related cancers. We aimed at examining the overall and specific cancer risks among hospitalized T1DM patients from the national registers in Sweden.

METHODS

A T1DM research cohort was created by identifying T1DM patients from the Hospital Discharge Register and linking them with the Cancer Registry. Standardized incidence ratios (SIRs) for subsequent cancers were calculated among patients with T1DM compared with those without T1DM.

RESULTS

Two hundred and fifty-eight cases were ascertained with subsequent cancers during the follow-up duration from 1964 to 2006, with an increased overall SIR of 1.17 (95% CI 1.04-1.33) among 24 052 T1DM patients identified at baseline. Significant excess was noted for gastric and skin (squamous cell carcinoma) cancers and for leukaemia. Increased risk of acute lymphatic leukaemia accounted for most of the variation of leukaemia risk (SIR = 5.31, 95% CI 3.32-8.05). Cancer risk varied with sex, age at first hospitalization and numbers of hospitalizations. The risk was higher in women compared with men and in those hospitalized for T1DM at age over 10 years compared with the younger patients. Higher risks were also found among those with more hospital visits.

CONCLUSION

By quantifying the variations of overall and site-specific cancer risks after T1DM, the current study provides novel associations between T1DM and subsequent cancers, the mechanisms of which remain to be established.

CA 72-4 levels in patients with type 2 diabetes mellitus

OBJECTIVE

CA 72-4 is one of the blood group carbohydrate antigens which can be used as a tumour marker in ovarian, pancreatic and gastrointestinal carcinomas. It can also be elevated in various benign conditions including pancreatitis. Diabetes mellitus is a chronic disorder related with the pancreas. In this study, we investigated CA 72-4 levels in patients with type 2 diabetes and its relation to the metabolic status.

METHODS

Sixty-nine patients with type 2 diabetes mellitus (female/male = 40/29) and 60 healthy subjects (female/male = 35/25) participated in this study. The levels of serum CA 72-4 were measured and faecal occult blood tests (following 3 days of white diet were obtained for three consecutive days) were performed in all patients. Patients had a pathological finding for any of these two parameters were further investigated with upper gastrointestinal endoscopy, colonoscopy and computerised tomography.

RESULTS

The mean levels of CA 72-4 was 1.89 +/- 2.61 U/ml in the study group and 1.4 +/- 0.98 U/ml in the control group (p > 0.05). There was no association between CA 72-4 levels and age and sex of the patients, duration of diabetes, body mass index, biochemical indicators of metabolic control (the levels of HbA(1c), fasting and postprandial glucose, serum lipids), the presence of microvascular complications (retinopathy, nephropathy, neuropathy) or treatment modalities.

CONCLUSIONS

Elevated levels of CA 72-4 in diabetic patients are not related to diabetes and it should be interpreted as evaluated in a non-diabetic patient.

Current challenges in clinical management of endometrial cancer

Endometrial cancer remains a management challenge. Improved understanding of the mechanisms of carcinogenesis may enable better understanding of biologic behavior and guide therapy. Improvements in diagnostic imaging, radiation delivery systems, and systemic therapies potentially can improve outcomes while minimizing morbidity. Novel strategies for screening and prevention also hold promise for reducing incidence and mortality of this disease.

Coffee drinking and endometrial cancer risk: a metaanalysis of observational studies

We conducted a metaanalysis of published studies on the relation between coffee drinking and endometrial cancer risk, which included 2 cohort (201 cases) and 7 case-control studies (2409 cases). The summary relative risk (RR) for coffee drinkers vs nondrinkers was 0.80 (95% confidence interval [CI], 0.68-0.94), with significant heterogeneity between studies. Compared with nondrinkers, the summary RR was 0.87 (95% CI, 0.78-0.97) for low-to-moderate coffee drinkers and 0.64 (95% CI, 0.48-0.86) for heavy coffee drinkers. The summary RR for an increase of 1 cup/d was 0.93 (95% CI, 0.89-0.97), which suggests an inverse relation between coffee and endometrial cancer. However, the causality must be confirmed.

Moving ahead in diabetics' cancer screening; food for thought from the Hellenic experience

Although data from literature suggest that diabetic women are frequently under screened for gynaecological cancers little is known about screening implementation for other cancers for both genders. This study investigates comprehensive cancer screening practices of diabetics as compared with non-diabetics; analyses screening patterns both by gender and level of evidence and reveals target subgroups that should be paid more attention for screening implementation. 675 diabetics vs. 5772 non-diabetic Greek individuals entered the PACMeR 02 cancer screening study. Diabetic women reported significantly lower performance for the sex-specific evidence-based cancer screening tests and digital rectal examination (DRE) as compared with non-diabetics (P < 0.05). Diabetic women older than 60 years old, of elementary education, housewives and farmers showed the lowest performance rates (P < 0.01). Prostate cancer screening was higher among diabetic men with ultrasound and DRE reaching statistical significance (P < 0.05). Subgroups analysis did not reveal a hidden relationship. Both genders of diabetics reported never performing skin examination at higher rates (P < 0.001), although screening intent is extremely low in both diabetics and non-diabetics (<1%). Evidence-based screening coverage was inconsistent in both genders independently by the diabetic status. Primary care efforts should be provided to implement presymptomatic cancer control.

Diabetes and endometrial cancer: effect modification by body weight, physical activity and hypertension

Among 777 endometrial cancer cases and 1550 controls from Italy and Switzerland, odds ratio was 1.7 (95% confidence interval: 1.2–2.5) for diabetes, and 5.1 for obese diabetic women as compared with non-obese non-diabetic ones. Diabetes shows a supramultiplicative effect with body mass index, but not with physical activity or hypertension.

Relationships of uterine and ovarian tumors to pre-existing chronic conditions

OBJECTIVE

Several chronic diseases have been hypothesized to affect the risk of subsequent gynecologic malignancies, possibly through shared hormonal mechanisms.

METHODS

Using record linkage techniques, we assessed the relationships between hospital and outpatient admissions for gallbladder disease, diabetes, hypertension, thyroid diseases and obesity and the subsequent development of uterine and ovarian cancers in Denmark between 1978 and 1998. Based on a subsample of more than 99,000 women, including 1398 uterine and 2491 ovarian cancers, we derived relative risks (RRs) and 95% confidence intervals (CIs) associated with overall and histology-specific cancer risks after adjustment for age, calendar time and reproductive characteristics.

RESULTS

Uterine cancers were related to previous diagnoses of thyroid diseases (RR=1.52, 95% CI 1.17-1.98) and obesity (2.05, 1.40-3.00). Associations with diabetes were confounded by obesity, but there were some elevations in risk for subjects diagnosed with obesity prior to age 45 (RRs 1.66-1.79). Although the "usual types" of endometrial cancer largely accounted for the observed associations, there was some evidence that uterine sarcomas (n=137) were related to prior diagnoses of thyroid diseases (2.78, 1.41-5.50). In contrast, ovarian cancers were not strongly related to most documented chronic diseases. Serous carcinomas were associated with gallbladder diseases of short durations, but detection bias or misdiagnosis probably accounts for this association. An association of obesity and endometrioid ovarian cancer was not identified.

CONCLUSIONS

Uterine cancers, including sarcomas, appear to be influenced by selected chronic diseases. Further attention should focus on possible biologic mechanisms underlying observed associations with thyroid diseases and obesity.

Physical activity and risk of endometrial cancer: the European prospective investigation into cancer and nutrition

The etiologic role of physical activity in endometrial cancer risk remains unclear given the few epidemiologic studies that have been conducted. To investigate this relation more fully, an analysis was undertaken in the European prospective investigation into cancer and nutrition (EPIC). During an average 6.6 years of follow-up, 689 incident endometrial cancer cases were identified from an analytic cohort within EPIC of 253,023 women. Cox proportional hazards models were used to estimate the associations between type of activity (total, occupational, household, recreational) and endometrial cancer risk. For total activity, women in the highest compared with the lowest quartile of activity had a risk of 0.88 (95% confidence interval (95% CI=0.61-1.27). No clear associations between each type of activity and endometrial cancer risk were found for the total study population combined. Associations were more evident in the stratified results, with premenopausal women who were active versus inactive experiencing a risk of 0.66 (95% CI=0.38-1.14) overall. Among premenopausal women, for household and recreational activities the risk estimates in the highest as compared with the lowest quartiles were, respectively, 0.48 (95% CI=0.23-0.99) and 0.78 (95% CI=0.44-1.39). No effect modification by body mass index, hormone replacement therapy, oral contraceptive use or energy intake was found. This study provides no evidence of a protective effect of increased physical activity in endometrial cancer risk in all women but some support for a benefit among premenopausal women. The relative risk reductions are most apparent for household activities.

Diabetes mellitus and risk of endometrial cancer: a meta-analysis

AIMS/HYPOTHESIS

Diabetes has been associated with a statistically significantly increased risk of endometrial cancer in most, but not all studies. To provide a quantitative assessment of the association between diabetes and risk of endometrial cancer, we conducted a meta-analysis of case-control studies and cohort studies.

SUBJECTS AND METHODS

We identified studies by a literature search of PubMed and Embase through to January 2007 and by searching the reference lists of relevant articles. Summary relative risks (RRs) with 95% CIs were calculated using random-effects model.

RESULTS

The analysis of diabetes (largely type 2) and endometrial cancer is based on 16 studies (three cohort and 13 case-control studies), including 96,003 participants and 7,596 cases of endometrial cancer. Twelve of the studies showed a statistically significantly increased risk and four a non-significant increased risk of endometrial cancer. In our meta-analysis we found that diabetes was statistically significantly associated with an increased risk of endometrial cancer (summary RR 2.10, 95% CI 1.75-2.53). The risk estimates were somewhat stronger among case-control (RR 2.22, 95% CI 1.80-2.74) than among cohort studies (RR 1.62, 95% CI 1.21-2.16), stronger among studies adjusting only for age (RR 2.74, 95% CI 1.87-4.00) compared with multivariate adjustment (RR 1.92, 95% CI 1.58-2.33) and slightly lower in studies performed in the USA than in those performed Europe. The analysis of type 1 diabetes and endometrial cancer was based on three studies and found a statistically significant positive association (summary RR 3.15, 95%CI 1.07-9.29).

CONCLUSIONS/INTERPRETATION

Results from the meta-analysis support a relationship between diabetes and increased risk of endometrial cancer.

Cancer, cardiovascular disease and diabetes mortality among women with a history of endometrial cancer

Among 7182 women with endometrial cancer in Scotland, standardised mortality ratios (and 95% confidence intervals (CI)) were 6.38 (5.74-7.15) for all cancers and 1.10 (1.00-1.22) for circulatory diseases as underlying cause of death and 2.81 (2.19-3.70) for diabetes as underlying/contributory cause of death.

Diabetes and risk of endometrial cancer: a population-based prospective cohort study

Although there is accumulating evidence that hyperinsulinemia in the context of insulin resistance is associated with carcinogenesis, only one prospective study of endometrial cancer incidence, in relation to diabetes, addressed this issue and showed no significant positive association. No previous study has investigated whether physical activity can modify the association between diabetes and endometrial cancer. We examined the association between diabetes and incidence of endometrial cancer and the potential effect modification by obesity and physical activity in the Swedish Mammography Cohort, a prospective cohort of 36,773 women, including 225 incident endometrial adenocarcinoma cases. After adjustments, the relative risk (RR) for endometrial cancer among women with diabetes comparing with nondiabetic women was 1.94 [95% confidence interval (95% CI), 1.23-3.08]. Among obese diabetics, the RR was 6.39 (95% CI, 3.28-12.06) compared with nonobese nondiabetic women. Among diabetics with low physical activity, the RR for endometrial cancer was 2.80 (95% CI, 1.62-4.85) compared with physically active nondiabetic women. Obese diabetics with low physical activity had a RR of 9.61 (95% CI, 4.66-19.83) compared with normal weight nondiabetic women with high physical activity. Diabetes was associated with a 2-fold increased risk, and combination of diabetes with obesity and low physical activity was associated with a further increased risk for endometrial cancer. Interventions to reduce body weight and increase physical activity may have important implications in terms of prevention of endometrial cancer and future management of diabetic subjects.

Screening and the prevention of gynecologic cancer: Endometrial cancer

Over the years, endometrial cancer has remained the most common gynecologic malignancy in the United States. Two categories of endometrial cancer exist: type I and type II. Type I cancers constitute the majority of cases of endometrial cancer, and the risk factors for this type have been studied in greatest detail. These cancers are driven by estrogen, and many of the risk factors are directly or indirectly linked to a state of excessive estrogen. Protective factors seem to be related to conditions that may result in decreased estrogen exposure. Cure rates for endometrial cancer remain high, mainly because of the early stage at which the majority of cases present. Warning signs of abnormal vaginal bleeding or discharge allow detection of these cancers in their early stages. Screening for these cancers is not effective and often leads to additional unnecessary tests; thus, it is not currently recommended in the general population.

Inflammation and Endometrial Cancer: A Hypothesis

Endometrial cancer is the most common gynecologic malignancy in the United States. Substantial epidemiologic data implicate an imbalance of estrogens and progestogens in the etiology of this disease. We propose that inflammation also plays a role in endometrial cancer development. Emerging laboratory data suggest that elevated levels of prostaglandin E(2) may underlie the transformation of normal endometrium to neoplastic tissue and that in vitro nonsteroidal anti-inflammatory drugs may inhibit endometrial cancer cell growth. In this review, we suggest that the risk factors for endometrial cancer--unopposed estrogens, anovulation, polycystic ovary syndrome, excessive menstruation, early menarche, and late menopause--may be viewed as factors increasing the exposure of the endometrium to inflammation, whereas pregnancy and smoking, two likely protective factors, have the opposite effect. Chronic inflammation can induce rapid cell division, increasing the possibility for replication error, ineffective DNA repair, and subsequent mutations. A proinflammatory milieu can also directly increase estrogen production. Hence, inflammation may work in conjunction with or in addition to estrogen exposure in the development of endometrial cancer.

Effect of adiposity and fat distribution on endometrial cancer risk in Shanghai women

The authors conducted a population-based case-control study of 832 endometrial cancer cases and 846 frequency-matched controls in Shanghai, China (1997-2001), to examine the association of overall adiposity and body fat distribution with disease risk. Overall adiposity was estimated using weight and body mass index (BMI); upper body fat distribution was evaluated using waist circumference and waist:hip ratio. Overall and upper-body obesity were both associated with an elevated risk of endometrial cancer. Adjusted odds ratios and 95% confidence intervals for highest-versus-lowest quartile comparisons were 2.6 (95% confidence interval (CI): 2.0, 3.5) for weight, 2.9 (95% CI: 2.2, 3.9) for BMI, 4.7 (95% CI: 3.4, 6.4) for waist circumference, and 3.5 (95% CI: 2.6, 4.8) for waist:hip ratio. The positive associations with weight and BMI vanished after results were controlled for waist circumference, while associations with waist circumference and waist:hip ratio persisted after adjustment for BMI. The positive association with upper-body obesity was more pronounced among younger women, women who had never used oral contraceptives, and women with a history of diabetes mellitus (p for multiplicative interaction < 0.05). Upper-body obesity was related to increased risk among women with low BMI. These results suggest that obesity, particularly upper-body fat deposition, is associated with an increased risk of endometrial cancer.

Association between Components of the Insulin-Like Growth Factor System and Endometrial Cancer Risk

OBJECTIVE

The insulin-like growth factor (IGF) system has been related to cell proliferation, obesity, diabetes, hyperinsulinemia and endometrial cancer risk. We used data from a case-control study conducted in Italy to provide additional information on the relation between the IGF system and endometrial cancer.

METHODS

A case-control study was conducted between 1999 and 2002 in Italy, including a total of 73 women with incident, histologically confirmed endometrial cancer and 108 controls admitted to the same hospital network for acute, nonneoplastic diseases. All subjects were interviewed using a validated questionnaire.

RESULTS

The odds ratios for endometrial cancer comparing the highest versus the lowest tertile of various IGF components were as follows: 0.5 [95% confidence interval (CI) 0.2-1.2] for free IGF-I, 1.1 (95% CI 0.5-2.6) for total IGF-I, 1.2 (95% CI 0.6-2.6) for total IGF-II, 2.4 (95% CI 1.0-5.9) for IGF binding protein (IGFBP)-1 and 0.8 (95% CI 0.4-2.0) for IGFBP-3. Further allowance for all IGF components in the model did not modify the results. The direct relation with IGFBP-1 was stronger and limited to heavier and older women.

CONCLUSIONS

The present findings suggest a limited effect of the IGF system on endometrial cancer risk. Increasing IGFBP-1 levels seem to be associated with endometrial cancer risk in older women and in women with a higher body mass index.

Diabetes mellitus as a predictor of cancer mortality in a large cohort of US adults

Several studies have suggested that diabetes mellitus may alter the risk of developing a variety of cancers, and the associations are biologically plausible. To learn more about the relation between diabetes and cancer mortality, the authors examined associations with selected cancers in a large, prospective US cohort of 467,922 men and 588,321 women who had no reported history of cancer at enrollment in 1982. After 16 years of mortality follow-up, diabetes was significantly associated with fatal colon cancer in men (multivariate relative risk (RR) = 1.20, 95% confidence interval (CI): 1.06, 1.37) and women (RR = 1.24, 95% CI: 1.07, 1.43) and with pancreatic cancer in men (RR = 1.48, 95% CI: 1.27, 1.73) and women (RR = 1.44, 95% CI: 1.21, 1.72). For men, diabetes was significantly associated with liver cancer (RR = 2.19, 95% CI: 1.76, 2.72) and bladder cancer (RR = 1.43, 95% CI: 1.14, 1.80). In addition, diabetes was significantly associated with breast cancer in women (RR = 1.27, 95% CI: 1.11, 1.45). These associations were not explained by high body mass. Our findings suggest that diabetes is an independent predictor of mortality from cancer of the colon, pancreas, female breast, and, in men, of the liver and bladder.

Managing women with post-menopausal bleeding

Transvaginal ultrasound examination can reliably distinguish women with post-menopausal bleeding (PMB) who are at low risk of endometrial pathology (endometrial thickness < or =4 mm) from those who are at high risk (endometrium > or =5 mm) and can rule out focally growing lesions in the uterine cavity using saline infusion into the cavity as a negative contrast agent (hydrosonography). The 5 mm cut-off is applicable irrespective of the use of hormone replacement therapy. It is justified to refrain from endometrial sampling in women with PMB and an endometrial thickness of < or =4 mm because the risk of endometrial cancer in these women is low (0.1-1.0%). However, it is not known whether these women need follow-up. About 80% of women with PMB and an endometrium of > or =5 mm have focally growing pathological lesions in the uterine cavity. These should be removed by operative hysteroscopy because dilatation and curettage (D and C) will fail to diagnose and remove a large proportion of these lesions. However, D and C is a reliable diagnostic method for women without focal lesions in the uterine cavity. It is not known whether simple outpatient sampling devices (e.g. Pipelle) are as reliable as D and C in women without focal lesions. A measurement of endometrial thickness is a simple and accurate method for estimating the risk of endometrial cancer. The reliability of ultrasound evaluation of endometrial morphology and/or vascularization for risk estimation of endometrial malignancy remains to be determined.

Glycemic index and glycemic load in endometrial cancer

Glycemic index (GI) and glycemic load (GL) are measures of the metabolic effects of dietary carbohydrates. The higher their value, the greater the glucose and insulin responses. Raised insulin levels are associated with endometrial cancer and with its risk factors including obesity, diabetes and hypertension. To study the role of the GI and GL we analyzed the data of two hospital-based case-control studies on endometrial cancer conducted between 1988-98 in Italy and Switzerland, including a total of 410 women with incident, histologically confirmed endometrial cancer and 753 controls admitted for acute, non-neoplastic diseases. A food frequency questionnaire was used to assess the subjects usual diet and to derive estimates of dietary GI and GL. The odds ratios (OR) of endometrial cancer, after adjustment for major risk factors, for the highest versus the lowest quintile of dietary GI and GL were 2.1 (95% confidence interval [CI] = 1.4-3.2) and 2.7 (95% CI = 1.8-4.2), respectively. The associations were stronger in older women, in those with higher body mass index and in hormone replacement therapy users. Our study supports the hypothesis of a direct association between GI and endometrial cancer risk.

Endometrial cancer and the IGF system: a case-control study in Greece

OBJECTIVES

Insulin-like growth factor I (IGF-I) and other components of the IGF system have been implicated in the etiology of several human malignancies. We have undertaken a case-control study among Greek women to explore the relation of major components of the IGF system (IGF-I, IGF-II and IGF-binding protein 3, IGFBP-3) with endometrial cancer risk.

METHODS

During a 1-year period (1999), 84 incident cases of histologically confirmed endometrial cancer were compared with 84 control women admitted to the same clinical department for small gynecological operations, mainly pelvic prolapse. Data were modeled through multiple logistic regression.

RESULTS

Endometrial cancer was positively associated with IGF-II and inversely with IGF-I. Both associations were statistically significant and they appear symmetrical around the null value. IGFBP-3 is positively associated with endometrial cancer risk, but this association does not reach statistical significance.

CONCLUSIONS

This study adds to the gradually developing consensus that components of the IGF system play a central role in human carcinogenesis. It is possible that IGF-II, rather than IGF-I, is closely linked to the etiology of endometrial cancer, the form of cancer most strongly associated with obesity.

Metabolic abnormalities (hypertension, hyperglycemia and overweight), lifestyle (high energy intake and physical inactivity) and endometrial cancer risk in a Norwegian cohort

Since high energy intake, inactivity, hypertension and diabetes are linked to obesity and an unfavorable hormonal profile, we wanted to test whether energy intake, physical activity, blood pressure and serum glucose are related to the risk of endometrial cancer independent of the body mass index (BMI). A cohort of 24,460 women, aged 20-49 years, attended a Norwegian health screening twice during 1974-1981; they answered questions about diet, physical activity and chronic diseases, and their height, weight, blood pressure and non-fasting serum glucose were measured. By the end of 1996, during 15.7 years of follow-up, 130 cases of endometrial carcinomas were identified. The relative risks (RRs) for endometrial cancer were estimated in proportional hazards models including potentially confounding factors. Obese women (BMI > or = 30 kg/m(2)) were at 2.6 times increased risk of endometrial cancer compared to normal weight women (BMI < 25 kg/m(2)) (RR = 2.57, 95%CI = 1.61-4.10). Among overweight women (BMI > or = 25 kg/m(2)), non-fasting serum glucose in the upper quartile vs. in the lower quartile was associated with a 2.4 times increase in risk (RR = 2.41, 95%CI = 1.08-5.37), whereas among obese women, blood pressure above 140/90 mmHg vs. below 140/90 mmHg in both surveys was associated with a 3.5 times increase in risk (RR = 3.47, 95%CI = 1.24-9.70). Especially in women younger than 50 years, high energy intake (5,044-6,401 kJ/day) conferred higher risk compared to low energy intake (< 4266 kJ/day) (RR = 3.40, 95%CI = 1.52-7.60). Increasing recreational activity tended to be protective. Among obese women with non-sedentary jobs at both screenings, RR declined to 0.18 (95%CI = 0.05-0.62) as the level of sustained occupational activity increased (p(trend) = 0.03). Our results suggest that inactivity and high energy intake are major risk factors for endometrial cancer independent of BMI, and that hypertension and relative hyperglycemia are significant markers of risk, especially among the heaviest women.

Plasma adiponectin concentrations in relation to endometrial cancer: a case-control study in Greece

Adiponectin is a hormone secreted exclusively by adipocytes, and obesity is an established risk factor for endometrial cancer. We have, thus, evaluated the association of adiponectin with the occurrence of endometrial cancer. Questionnaire information and blood samples were taken before treatment from 84 women with newly diagnosed, histologically confirmed endometrial cancer and 84 control women who were admitted for minor gynecologic problems, mainly pelvic prolapse. Adiponectin levels were measured by immunoassay. The results were analyzed through multiple logistic regression and controlled for known risk factors for endometrial cancer, leptin, as well as major components of the IGF system (IGF-I, IGF-II, and IGF-binding protein 3). Among control women, there was no significant association of adiponectin with age or parity. Although there was no association of adiponectin with endometrial cancer among women 65 yr or older, there was an inverse, fairly strong, and statistically significant inverse association among younger women. Among women younger than 65 yr, an increase of adiponectin by 1 SD was associated with a more than 50% reduction of the risk for endometrial cancer [odds ratio (OR) 0.44; 95% confidence interval (CI) 0.24-0.81], even after controlling for body mass index and other potential confounders. Among all women, the adjusted OR for a 1 SD increase in adiponectin was not significant (OR, 0.78; 95% CI, 0.56-1.10) but was significant for a one quintile increase in adiponectin (OR, 0.74; 95% CI, 0.56-0.97). In women younger than 65 yr, among whom obesity represents a powerful risk factor for endometrial cancer, adiponectin is inversely and significantly related to the risk of this disease. This association is independent of possible effects of major components of the IGF system, leptin, body mass index, sociodemographic variables, and known endometrial cancer risk factors. Future studies are needed to prove causality and provide insight on both the mechanism of action of this hormone and its potential role in endometrial cancer.

1alpha,25-Dihydroxyvitamin D(3) inhibits rat liver ultrastructural changes and the development of gamma-glutamyltranspeptidase-positive foci in diethylnitrosamine-initiated and streptozotocin-induced diabetes-promoted hepatocarcinogenesis

In the present study, the chemopreventive effect of the active metabolite of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (VD(3)), against chemically-induced and diabetes-promoted rat liver carcinogenesis was investigated. Hepatocarcinogenesis was initiated with a single intraperitoneal (i.p.) injection of diethylnitrosamine (DEN) (125 mg kg(-1) body weight) at week 4 followed by promotion with streptozotocin (STZ) (65 mg kg(-1) body weight with a single i.p. injection) at week 7. With this basic experimental regimen, the effect of VD(3) (0.3 microg (0.1 ml)(-1) propylene glycol per os twice a week) was investigated with effect from 4 weeks prior to the exposure of DEN. The results showed that VD(3) supplementation throughout the experimental period reduced the incidence, total number and multiplicity and altered the size of visible persistent nodules (PNs) in DEN- or DEN + STZ-treated rats as compared with their respective controls. In these two groups, it also caused a significant decrease in the number (p < 0.002 and 0.001 respectively) and focal area (p < 0.05) of gamma-glutamyltranspeptidase (GGT)-positive hepatic foci. Moreover, continuous supplementation of VD(3) exhibits a protective effect in maintaining the normal cellular architecture of the hepatocytes in DEN- or DEN + STZ-treated rats. Our results thus strongly suggest that VD(3) is very effective in the inhibition of DEN-initiated and STZ-induced diabetes-promoted rat liver carcinogenesis.

Role of exogenous and endogenous hormones in endometrial cancer: review of the evidence and research perspectives

Endometrial carcinoma is the most common cancer of the female reproductive organs in the United States. International comparisons reveal that the incidence of endometrial cancer vary widely between different countries with the highest rates observed in North America and Northern Europe, intermediate rates in Eastern Europe and Latin America, and lowest rates in Asia and Africa. International variation in endometrial cancer rates may represent differences in the distribution of known risk factors, which include obesity, postmenopausal estrogen replacement, ovarian dysfunction, diabetes mellitus, infertility, nulliparity, and tamoxifen use. Most of the risk factors for endometrial cancer can be explained within the framework of the unopposed estrogen hypothesis, which proposes that exposure to estrogens unopposed by progesterone or synthetic progestins leads to increased mitotic activity of endometrial cells, increased number of DNA replication errors, and somatic mutations resulting in malignant phenotype. Although the impact of exogenous hormone replacement was intensively studied during the last two decades, less is known about the effects of endogenous hormones in endometrial cancer. A review of available experimental, clinical, and epidemiologic data suggests that in addition to estrogens, other endogenous hormones, including progesterone, androgens, gonadotropins, prolactin, insulin, and insulin-like growth factors, may play a role in the pathogenesis of different histopathologic types of endometrial cancer.

Epidemiology of endometrial cancer

Endometrial cancer is the commonest gynaecological cancer mostly affecting women in the post-menopausal age group. Rates vary worldwide and are highest in white women in Western populations. Some risk factors are related to reproduction, such as early age at menarche, late age at menopause and nulliparity, while others are more directly oestrogen-related, for example, conditions such as the polycystic ovarian syndrome. Use of unopposed oestrogen replacement therapy is associated with an increased risk, and use of the combined oral contraceptive pill is associated with a decreased risk. The relationship between tamoxifen and endometrial cancer is not established. Obesity, diabetes and hypertension increase the risk of endometrial cancer while smoking, low-fat diets and physical exercise appear to decrease the risk; all of these possibly exert their effects by various indirect influences on oestrogen levels, thus influencing the level of stimulation of the target endometrial epithelium.

Energy balance and cancer: the role of insulin and insulin-like growth factor-I

Recent theories propose that a Western lifestyle may increase cancer risk through alterations in the metabolism of insulin and insulin-like growth factors (IGF: McKeown-Eyssen, 1994; Giovannucci, 1995; Kaaks, 19%; Werner & LeRoith, 1996). Insulin regulates energy metabolism, and increases the bioactivity of IGF-I, by enhancing its synthesis. and by decreasing several of its binding proteins (IGFBP; IGFBP-1 and -2). Insulin and IGF-I both stimulate anabolic processes as a function of available energy and elementary substrates (e.g. amino acids). The anabolic signals by insulin or IGF-I can promote tumour development by inhibiting apoptosis, and by stimulating cell proliferation. Furthermore, both insulin and IGF-I stimulate the synthesis of sex steroids, and inhibit the synthesis of sex hormone-binding globulin (SFIBG), a binding protein that regulates the bioavailability of circulating sex steroids to tissues. The present paper reviews epidemiological findings relating the risk of cancers of the colo-rectum, pancreas, breast, endometrium and prostate to body size (obesity, height) and physical activity, and discusses the relationships between obesity and physical activity and plasma levels of insulin, IGF-I and IGFBP. Subsequent sections review epidemiological findings relating cancer risk to indices of chronic hyperinsulinaemia, and to plasma levels of IGF-I and IGFBP. Conclusions are that chronic hyperinsulinaemia may be a cause of cancers of the colon, pancreas and endometrium, and also possibly of the breast. On the other hand, elevated plasma IGF-I, as total concentrations or relative to levels of IGFBP-3, appears to be related to an increased risk of prostate cancer, breast cancer in young women, and possibly cob-rectal cancer. For cancers of the endometrium, breast and prostate, these findings are discussed in the context of relationships between insulin and IGF-I and levels of bioavailable sex steroids.

The relation of type 2 diabetes and cancer

Increasing evidence indicates that individuals with type 2 diabetes (diabetes) are at elevated risk for several common human malignancies, including cancers of the colon, breast, endometrium, pancreas, and liver. In particular, the consistent positive results reported by prospective investigations make it unlikely that methodologic issues, occult tumors, or chance results could explain the findings. Since diabetes and impaired fasting glucose together affect >25% of Americans above age 50, even a moderate etiologic association (e.g., relative risk = 1.5) would explain >10% of involved malignancies. Laboratory studies have suggested biologically plausible mechanisms. Insulin, for example, is typically at high levels during the development and early stages of diabetes. Activation of the insulin receptor by its ligand, or cross-activation of the insulin-like growth factor-I receptor, has been shown to be mitogenic and promote tumorigenesis in various model systems. A "unifying concept," in fact, holds that hyperinsulinemia may underlie the cancer associations of several additional risk factors, including high waist circumference, visceral fat, waist-to-hip ratio, body mass index, sedentary lifestyle, and energy intake. In this review, we assess current evidence regarding the relation of type 2 diabetes with cancer, and evaluate the findings in terms of well-accepted criteria for establishing causality.