Dietary iron intake and risk of endometrial cancer: a population-based case-control study in Shanghai, China

Assessment of Serum Zn, Cu, Mn, and Fe Concentration in Women with Endometrial Cancer and Different Endometrial Pathologies

BACKGROUND

There is conflicting evidence on the effect of specific micronutrient concentration and cancer risk. In this study, we investigated the differences in serum zinc, copper, iron, and manganese levels and different endometrial pathologies, including endometrial cancer.

METHODS

110 patients with a confirmed diagnosis of endometrial cancer, benign uterine conditions (endometrial polyp, endometrial hyperplasia, uterine myoma), or normal endometrium were included in the study and assessed in terms of endometrial cancer risk factors. The measurements of serum micronutrients were conducted using inductively coupled plasma optical emission spectrometry.

RESULTS

When assessing for differences between serum concentrations of trace metals, we found significant differences in the distribution of Mn (p < 0.001) and Fe (0.034). There was also a significant difference in Cu/Zn ratio between the analyzed groups (p = 0.002). Patients' BMI was found to influence Cu concentration, with obese patients having higher mean copper concentration (p = 0.006). Also, patients' menopausal status was shown to influence Cu concentration with postmenopausal patients having higher Cu levels (p = 0.001). The menopausal status was found to influence Cu/Zn ratio (p = 0.002). Univariable regression analysis did not confirm that any of the micronutrients significantly influence the risk of endometrial cancer.

CONCLUSION

The concentration of specific trace metals varies between different histopathological diagnoses of endometrial pathologies. Menopausal status and patient BMI are endometrial cancer risk factors impacted by the concentrations of Cu and Zn and their ratio.

Ferroptosis: Opportunities and Challenges in Treating Endometrial Cancer

Ferroptosis, a new way of cell death, is involved in many cancers. A growing number of studies have focused on the unique role of ferroptosis on endometrial cancer. In this study, we made a comprehensive review of the relevant articles published to get deep insights in the association of ferroptosis with endometrial cancer and to present a summary of the roles of different ferroptosis-associated genes. Accordingly, we made an evaluation of the relationships between the ferroptosis-associated genes and TNM stage, tumor grade, histological type, primary therapy outcome, invasion and recurrence of tumor, and accessing the different prognosis molecular typing based on ferroptosis-associated genes. In addition, we presented an introduction of the common drugs, which targeted ferroptosis in endometrial cancer. In so doing, we clarified the opportunities and challenges of ferroptosis activator application in treating endometrial cancer, with a view to provide a novel approach to the disease.

The Influence of Iron and Zinc Supplementation on Iron Apparent Absorption in Rats Fed Vitamins and Minerals Reduced Diets

Deficient human diet is usually reduced in many nutrients, but animal studies on iron absorption have been only carried out for rats fed well-balanced (control) and iron-deficient diets. The aim of this study was to evaluate the effect of iron or iron/zinc supplementation on iron apparent absorption (IAA) in rats fed a diet reduced in all vitamins and minerals (R). The study was conducted on 77, 6-week-old male Wistar rats in 3 stages as follows: stage I, 4-week period of adaptation to R diet (50% less vitamins and minerals compared to AIN-93M recommendations); stage II, 4-week supplementation period with iron (RSFe) or iron/zinc (RSFeZn); stage III, 2-week post-supplementation period (rats fed R diet). Feces samples to IAA determination were collected at the 20-22nd days of stage I and II and the 10-12th days of stage III. To determine the changes in IAA after introducing and discontinuation of supplementation, feces were collected for 3 days after introducing (stage II) and 5 days after the supplementation discontinuation (stage III). At the end of stage II, compared to R rats, the IAA was statistically significantly higher in RSFe and RSFeZn rats (30.3 ± 2.0% vs. 47.4 ± 1.2% and 51.0 ± 1.7%, respectively). After introducing iron or iron/zinc supplementation, the IAA stabilized fast already in the first day, while after discontinuation of the supplementation, at least 4 days was required to the stabilization. At the end of stage III, the IAA was significantly lower in RSFe (15.8 ± 6.6%) than in RSFeZn rats (43.4 ± 5.9%). In conclusion, to confirm that iron and zinc supplementation is more beneficial than iron supplementation only, especially after discontinuation of supplementation, further research among humans is necessary.

A Narrative Review of the Role of Diet and Lifestyle Factors in the Development and Prevention of Endometrial Cancer

Simple Summary

The incidence and prevalence of endometrial cancer is increasing globally. The main factors involved in this increase have been the way women live today and what they eat and drink. In fact, the obesity pandemic that is sweeping across the planet is considered to be the main contributory feature. This review aims to introduce to a new audience, those that are not experts in the field, what is known about the different types of endometrial cancer and the mechanisms for their induction and protection. We also seek to summarise the existing knowledge on dietary and lifestyle factors that prevent endometrial development in susceptible populations and identify the main problem in this arena; the paucity of research studies and clinical trials that investigate the interaction(s) between diet, lifestyle and endometrial cancer risk whilst highlighting those areas of promise that should be further investigated.

Abstract

Endometrial cancer is the most common cancer affecting the reproductive organs of women living in higher-income countries. Apart from hormonal influences and genetic predisposition, obesity and metabolic syndrome are increasingly recognised as major factors in endometrial cancer risk, due to changes in lifestyle and diet, whereby high glycaemic index and lipid deposition are prevalent. This is especially true in countries where micronutrients, such as vitamins and minerals are exchanged for high calorific diets and a sedentary lifestyle. In this review, we will survey the currently known lifestyle factors, dietary requirements and hormonal changes that increase an individual’s risk for endometrial cancer and discuss their relevance for clinical management. We also examine the evidence that everyday factors and clinical interventions have on reducing that risk, such that informed healthy choices can be made. In this narrative review, we thus summarise the dietary and lifestyle factors that promote and prevent the incidence of endometrial cancer.

Heme, an essential nutrient from dietary proteins, critically impacts diverse physiological and pathological processes

Heme constitutes 95% of functional iron in the human body, as well as two-thirds of the average person’s iron intake in developed countries. Hence, a wide range of epidemiological studies have focused on examining the association of dietary heme intake, mainly from red meat, with the risks of common diseases. High heme intake is associated with increased risk of several cancers, including colorectal cancer, pancreatic cancer and lung cancer. Likewise, the evidence for increased risks of type-2 diabetes and coronary heart disease associated with high heme intake is compelling. Furthermore, recent comparative metabolic and molecular studies of lung cancer cells showed that cancer cells require increased intracellular heme biosynthesis and uptake to meet the increased demand for oxygen-utilizing hemoproteins. Increased levels of hemoproteins in turn lead to intensified oxygen consumption and cellular energy generation, thereby fueling cancer cell progression. Together, both epidemiological and molecular studies support the idea that heme positively impacts cancer progression. However, it is also worth noting that heme deficiency can cause serious diseases in humans, such as anemia, porphyrias, and Alzheimer’s disease. This review attempts to summarize the latest literature in understanding the role of dietary heme intake and heme function in diverse diseases.

The effect of iron and zinc supplementation and discontinuation of this practice on iron and zinc level in tissues in rats fed deficient diets

The effect of iron and iron/zinc supplementation on their levels in tissues of rats fed initially one of the three following regimen: C - control AIN-93 diet, D - iron deficient diet and R - diet with 50% reduction of all vitamins and minerals was investigated. The study was conducted on 6-week male Wistar rats, in 3 stages: (1) 4-week adaptation to the diets (C, D or R); (2) 4-week supplementation with the same regimen enriched with 10-times more iron (CSFe, DSFe, RSFe) or iron/zinc (CSFeZn, DSFeZn, RSFeZn); (3) 2-week post-supplementation period (the same diets as the stage I). Iron and zinc content in serum, the initial segment of intestine, liver and kidney were measured using FAAS method. After supplementation period (stage II) the content of iron in the intestine, liver and kidney in groups of rats fed DSFe and DSFeZn-diet were significantly higher (all p-values≤0.05) than in rats fed D-diet (intestine: DSFe=50.1±9.0 μg/g wet weight, DSFeZn=43.0±9.9 μg/g vs. D=16.5±2.1 μg/g; liver: DSFe=149±30 μg/g, DSFeZn=152±25 μg/g vs. D=56±13 μg/g; kidney: DSFe=74.0±8.1 μg/g, DSFeZn=72.7±6.6 μg/g vs. D=59.3±9.5 μg/g). The same significant associations (all p-values≤0.05) were observed in R rats in the intestine and liver (intestine: RSFe=60.8±6.6 μg/g, RSFeZn=54.8±6.6 μg/g vs. R=31.5±8.2 μg/g; liver: RSFe=161±10 μg/g, RSFeZn=166±21 μg/g vs. R=136±24μg/g). After post-supplementation period the statistically significant differences between supplemented and non-supplemented rats fed D- and R-diets were still observed. There was not found the effect of applied treatments on zinc status. In conclusion, iron or iron/zinc supplementation increased similarly iron level in tissues of rats fed D-diet or R-diet with prolonged effect after supplementation discontinuation.

Heme Iron Intake and Risk of Stroke

Background and Purpose—

Intake of iron, especially heme iron, has been associated with several diseases. However, epidemiological studies of heme iron and nonheme iron intake in relation to risk of stroke are lacking. The aim of this study was to examine the associations between heme iron and nonheme iron intake and stroke incidence in men.

Methods—

The population-based prospective Cohort of Swedish Men included 38 859 men, aged 45 to 79 years, who had no history of stroke, coronary heart disease, or cancer at baseline. Hazard ratios and 95% confidence intervals (95% CIs) were calculated using Cox proportional hazards regression models.

Results—

During an 11.7 years follow-up, 3097 incident cases of stroke, including 2482 cerebral infarctions and 450 intracerebral hemorrhages, were registered. The hazard ratios of total stroke and cerebral infarction for the highest compared with the lowest quintiles of heme iron intake were 1.16 (95% CI, 1.03–1.31; P trend=0.037) and 1.15 (95% CI, 1.00–1.31; P trend=0.089), respectively. The incidence rates of total stroke per 10 000 person-years were 72.6 in the lowest quintile and 84.4 in the highest. The association was confined to men with body mass index <25 kg/m 2 , the hazard ratios were 1.40 (95% CI, 1.17–1.68; P trend<0.001) for total stroke and 1.38 (95% CI, 1.13–1.70; P trend=0.001) for cerebral infarction; no association was observed among overweight and obese men. There was no association between nonheme iron intake and risk of total stroke and stroke types.

Conclusions—

Findings from this prospective study indicate that a high heme iron intake, particularly in normal weight individuals, may increase the risk of stroke.

Long-term dietary heme iron and red meat intake in relation to endometrial cancer risk

BACKGROUND

Heme and total iron, present in meat, have been hypothesized to promote carcinogenesis. Few prospective studies have examined the associations between intakes of heme and total iron, types of meat, and endometrial cancer risk.

OBJECTIVE

We evaluated the associations between intakes of heme and total iron, types of meat, and risk of endometrial cancer in a large cohort of women.

DESIGN

Among 60,895 women in the Swedish Mammography Cohort, 720 endometrial cancer cases were confirmed during 21 y of follow-up. RRs and 95% CIs were calculated by Cox proportional hazards models.

RESULTS

A comparison of the highest with the lowest quartile showed a 20-30% higher risk of endometrial cancer for higher intakes of heme iron (RR: 1.24; 95% CI: 1.01, 1.53 for ≥1.63 compared with <0.69 mg/d), total iron (RR: 1.31; 95% CI: 1.07, 1.61 for ≥15.09 compared with <12.27 mg/d), and liver (RR: 1.29; 95% CI: 1.06, 1.56 for ≥100 compared with <100 g/wk). No statistically significant associations were observed between intakes of red and processed meats and endometrial cancer risk. RRs did not greatly differ when we stratified by BMI, parity, and intakes of alcohol, vitamin C, or zinc or when we excluded patients with diabetes.

CONCLUSIONS

Our study suggests a modest positive association between heme iron, total iron, and liver intakes and endometrial cancer risk; no statistically significant associations were observed for intakes of other red and processed meats and endometrial cancer risk.

Risk of endometrial cancer in relation to individual nutrients from diet and supplements

OBJECTIVE

Intake of nutrients may influence the risk of endometrial cancer (EC). We aimed to estimate the association of intake of individual nutrients from food and from food plus supplements with EC occurrence.

DESIGN

A population-based case-control study conducted in Canada (2002-2006).

SETTING

Nutrient intakes from food and supplements were assessed using an FFQ. Logistic regression was used to estimate EC risk within quartile levels of nutrient intakes.

SUBJECTS

Incident EC cases (n 506) were identified from the Alberta Cancer Registry, and population controls were frequency- and age-matched to cases (n 981).

RESULTS

There existed little evidence of an association with EC for the majority of macronutrients and micronutrients examined. We observed a statistically significant increased risk associated with the highest, compared with the lowest, quartile of intake of dietary cholesterol (multivariable-adjusted OR = 1·51, 95 % CI 1·08, 2·11; P for trend = 0·02). Age-adjusted risk at the highest level of intake was significantly reduced for Ca from food sources (OR = 0·73, 95 % CI 0·54, 0·99) but was attenuated in the multivariable model (OR = 0·82, 95 % CI 0·59, 1·13). When intake from supplements was included in Ca intake, risk was significantly reduced by 28 % with higher Ca (multivariable-adjusted OR = 0·72, 95 % CI 0·51, 0·99, P for trend = 0·04). We also observed unexpected increased risks at limited levels of intakes of dietary soluble fibre, vitamin C, thiamin, vitamin B6 and lutein/zeaxanthin, with no evidence for linear trend.

CONCLUSIONS

The results of our study suggest a positive association between dietary cholesterol and EC risk and an inverse association with Ca intake from food sources and from food plus supplements.