Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

Gender Differences in Soft Tissue and Bone Sarcoma: A Narrative Review

Sarcomas, uncommon malignancies, stem from mesenchymal tissues, distinct from epithelial tissues, originating in the embryonic mesodermal layer. These sarcomas have been categorized as either bone or soft tissue sarcomas, depending on their originating tissue. The majority of sarcomas occur sporadically with their etiology being unknown, but there are several, well-established genetic predisposition syndromes and some environmental exposures associated with specific sarcomas. Recently, many studies have shown that sarcomas, in analogy with colorectal, skin, head and neck, esophageal, lung, and liver carcinomas, also have a male sex predilection. Significant gender differences have already been observed in childhood sarcomas. Among the tumors strongly associated with the male sex, childhood sarcomas have been identified as being particularly sensitive to the biological differences between the sexes, with special regard to soft tissue sarcomas. As the biological mechanisms underlying the sex differences in the incidence of soft tissue sarcomas remain largely unexplored, this review aims to highlight the factors underlying these differences to inform prevention and treatment.

Raloxifene increases the risk of gastroesophageal reflux disease, Barrett's esophagus, and esophageal stricture in postmenopausal women with osteoporosis

BACKGROUND AND AIMS

Estrogen-based therapies may increase the risk of gastroesophageal reflux (GERD) and its complications. We aimed to determine the effect of raloxifene on the development of GERD, Barrett's esophagus, and esophageal stricture in postmenopausal women with osteoporosis.

METHODS

This was a population-based, propensity-matched cohort study using the TriNetX platform. Patients 50 years and older with a diagnosis of "menopause" and "osteoporosis" were included in this study. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for new GERD, esophageal stricture and Barrett's esophagus after raloxifene exposure. The control cohort consisted of patients who did not start any hormonal replacement therapy. We conducted a multivariable logistic regression analysis to evaluate the effect of confounding variables and also addressed common confounding medications with 1:1 propensity score-matching. Internal validity was confirmed by comparing to negative controls (lisinopril, atorvastatin) and positive controls (metformin, ibuprofen, aspirin).

RESULTS

Five thousand four hundred and seventy two postmenopausal women with osteoporosis were on raloxifene of which 1908 (34.86%) developed GERD, compared to 296,067 postmenopausal who were not on raloxifene of which 90,643 (30.62%) developed GERD (OR 1.2; 95% CI 1.10-1.31, p < 0.0001). This persisted after adjusting for common medications known to affect GERD. Raloxifene was identified as a risk factor for GERD in a multivariate analysis, controlling for factors including age, obesity, smoking, and alcohol use (OR 1.51, 95% Wald CI 1.47-1.53). Raloxifene was associated with esophageal stricture (OR 1.60; 95% Wald CI 1.51-1.69) and Barrett's esophagus (OR 1.50; 95% Wald CI 1.37-1.63) in multivariate analysis. These associations persisted using sensitivity analyses.

CONCLUSION

Raloxifene increases the risk of GERD, esophageal stricture and Barrett's esophagus in postmenopausal women with osteoporosis. Further studies are needed to confirm our findings.

Female Sex but Not Oestrogen Receptor Expression Predicts Survival in Advanced Gastroesophageal Adenocarcinoma-A Post-hoc Analysis of the GO2 Trial

Gastroesophageal adenocarcinoma is a disease of older adults that is associated with a very poor prognosis. It is less common and has better outcomes in females. The reason for this is unknown but may relate to signalling via the main oestrogen receptors (ER) α and β. In this study, we sought to investigate this using the GO2 clinical trial patient cohort. GO2 recruited older and/or frail patients with advanced gastroesophageal cancer. Immunohistochemistry was performed on tumour samples from 194 patients. The median age of the population was 76 years (range 52-90), and 25.3% were female. Only one (0.5%) tumour sample was positive for ERα, compared to 70.6% for ERβ expression. There was no survival impact according to ERβ expression level. Female sex and younger age were associated with lower ERβ expression. Female sex was also associated with improved overall survival. To our knowledge, this is the largest study worldwide of ER expression in a cohort of patients with advanced gastroesophageal adenocarcinoma. It is also unique, given the age of the population. We have demonstrated that female sex is associated with better survival outcomes with palliative chemotherapy but that this does not appear to be related to ER IHC expression. The differing ER expression according to age supports the concept of a different disease biology with age.

The effect of combined oral contraceptives and Nexplanon on gastroesophageal reflux disease in premenopausal women: A nationwide database analysis

BACKGROUND

Pregnancy, combined oral contraceptives (COC), and hormone replacement therapy have been reported to increase the risk of gastroesophageal reflux disease (GERD). To date, no study has evaluated the effect of Nexplanon, a commonly used progesterone-based contraceptive, on GERD. We aimed to determine the effect of Nexplanon and COC on GERD.

METHODS

We performed a population-based analysis using the IBM Explorys national database (1999-2021). The study group included premenopausal women, defined as women less than 50 years of age while excluding the diagnosis of menopause. The effect of Nexplanon and COC on GERD (at least 30 days after Nexplanon/COC was initiated) was assessed by comparing it to premenopausal women who were not on contraceptives. Foregut surgery, esophageal dysmotility disorders, hiatal hernia, and delayed gastric emptying were excluded. Odds ratios (OR) with 95% confidence intervals (CI) were calculated. A multivariate logistic regression analysis was conducted.

KEY RESULTS

A total of 23,299,470 patients were identified as being premenopausal, of which 47,260 were on Nexplanon and 5480 on COCs. As compared to premenopausal women with GERD on no contraceptives (n = 565,880), 690 patients developed GERD at least 30 days after being on Nexplanon (OR = 0.55, 95% CI [0.51-0.59], p < 0.001) and 280 developed GERD after COC (1.93, [1.71-2.18], p < 0.001). A multivariate analysis accounting for Caucasian race, obesity, smoking, alcohol use, and NSAIDs revealed that COC is an independent risk factor for GERD (1.16, [1.12-1.20], p < 0.001), and Nexplanon was protective against GERD (0.90, [0.89-0.92], p < 0.001). Hydralazine was used as a control medication for data reliability. A total of 8420 patients developed GERD after initiating hydralazine, which was not statistically nor clinically significant (OR = 1.02, 95% CI [0.99-1.04], p = 0.08) when compared to those not on contraceptives.

CONCLUSIONS & INFERENCES

Combined oral contraceptives is an independent risk factor for GERD, while Nexplanon has a limited protective effect. Further studies are needed to confirm the different effects on GERD of these two contraceptives.

Association of hormone replacement therapy with risk of gastric cancer: a systematic review and meta-analysis

Hormone replacement therapy (HRT) is widely used to relieve menopausal symptoms; however, it remains unclear whether the use of HRT was associated with gastric cancer. We conducted a systematic review and meta-analysis to synthesize available evidence. This study followed the PRISMA guideline to report meta-analysis. PubMed, Embase, and Cochrane library were searched from conception through 23 February 2022. Eligible studies reporting risk of gastric cancer after HRT were screened and accessed by two independent reviewers. Random-effects meta-analysis was used to calculate pooled risk estimate as relative risk (RR, 95% CI). Pre-established review protocol was registered in PROSPERO (CRD42021281260). Among the 1095 articles identified, we included 11 studies with 1,919,089 women in this meta-analysis. The combined risk estimate (RR, 0.72; 95% CI 0.64–0.81; I² = 2%) indicated that the use of HRT was associated with a 28% reduction in risk of gastric cancer compared with those who had no HRT exposure. The narrow prediction interval (0.62–0.84) for gastric cancer risk suggested a low between-study variance. In subgroup analysis defined by HRT formulation, there were reduction in risks of gastric cancer after the use of estrogen-only therapy (Pooled RR, 0.63; 95% CI 0.51–0.77, I² = 0%) and estrogen-progestin therapy (Pooled RR, 0.70; 95% CI 0.57–0.87; I² = 0%), as compared with non-users. In this systematic review and meta-analysis, the use of HRT was associated with a reduced gastric cancer risk regardless of HRT formulation. Further investigations are warranted to confirm underlying mechanisms.

Risk of esophageal and gastric adenocarcinoma in men receiving androgen deprivation therapy for prostate cancer

The aim of this study was to explore the male predominance in esophageal and gastric adenocarcinoma by evaluating the preventive potential of androgen deprivation therapy (ADT). This matched cohort study was based on a national Swedish database of prostate cancer patients in 2006-2013. Prostate cancer patients receiving ADT were the exposed group. Prostate cancer-free men from the general population were randomly selected and matched to the index case by birth year and county of residence, forming the unexposed control group. The participants were followed until a diagnosis of esophageal or gastric cancer, death, emigration, or end of the study period. The risk of esophageal adenocarcinoma, cardia gastric adenocarcinoma, non-cardia gastric adenocarcinoma, and esophageal squamous-cell carcinoma among ADT-exposed compared to unexposed was calculated by multivariable Cox proportional hazard regression. The hazard ratios (HRs) and 95% confidence intervals (CIs) were adjusted for confounders. There was a risk reduction of non-cardia gastric adenocarcinoma among ADT-users compared to non-users (HR 0.49 [95% CI 0.24-0.98]). No such decreased risk was found for esophageal adenocarcinoma (HR 1.17 [95% CI 0.60-2.32]), cardia gastric adenocarcinoma (HR 0.99 [95% CI 0.40-2.46]), or esophageal squamous cell carcinoma (HR 0.99 [95% CI 0.31-3.13]). This study indicates that androgen deprivation therapy decreases the risk of non-cardia gastric adenocarcinoma, while no decreased risk was found for esophageal adenocarcinoma, cardia gastric adenocarcinoma, or esophageal squamous-cell carcinoma.

Long-term response on letrozole for gastric cancer: A case report

RATIONALE

Hormone therapies, particularly those targeting estrogen and its receptors, are a key treatment modality for patients with estrogen receptor (ER)-positive breast or ovarian cancer. Some gastric cancers (GCs) express ERs, and preclinical studies suggest the potential of estrogen-targeting hormone therapy on GC; however, the clinical relevance of this hormone therapy on GC treatment has not been well elucidated.

PATIENT CONCERNS

An 80-year-old female was admitted to our department with hypogastric pain and vomiting. Computed tomography demonstrated small bowel obstruction, and laparotomy after bowel decompression revealed peritoneal dissemination consisting of a poorly-differentiated adenocarcinoma. Intestinal bypass between the ileum and transverse colon was performed.

DIAGNOSES

The tumor was ER- and mammaglobin-positive, indicating that it originated from a breast cancer. Diagnostic imaging revealed no evidence of breast cancer; however, right axillary ER- and mammaglobin-positive lymphadenopathy was found.

INTERVENTIONS

The patient received hormone therapy using letrozole based on a clinical diagnosis of occult breast cancer with peritoneal dissemination and right axillary lymph node metastasis.

OUTCOMES

The patient remained disease free until 37 months but deceased at 53 months from the onset of disease. An autopsy revealed no tumor cells in the right breast tissue; however, there was a massive invasion of cancer cells in the stomach.

LESSONS

A patient with ER positive GC with peritoneal dissemination and right axillary lymph node metastasis presented remarkable response to letrozole. The long-term survival obtained using letrozole for a patient with GC with distant metastasis suggests the potential of estrogen targeting hormone therapies for GC.

Trends in incidence and mortality of esophageal cancer in Inner Mongolia, 2010-2015

Background

Esophageal cancer is among the leading cancer types in Inner Mongolia. This study aimed to investigate the incidence and mortality rates of esophageal cancer in 2015 and the trends in these rates in the 2010–2015 period in this region.

Methods

National Colorectal Cancer Roundtable (NCCR) screening methods and criteria were used to extract data from 10 cancer registries stratified by area (urban/rural), sex, and age group. The Chinese standard population in 2000 and Segi's world population were used to calculate age‐standardized rates. The annual percentage change (APC) in these rates was calculated using the Joinpoint Regression Program.

Results

In 2015, Inner Mongolia had 4324 new cases (4027 male vs. 297 female patients) and 3559 deaths (3300 male vs. 259 female patients) from esophageal cancer. The crude incidence, age‐standardized incidence by Chinese population, age‐standardized incidence by world population, and cumulative incidence were 13.45/100 000, 9.92/100 000, 10.18/100 000, and 1.30%, respectively. The corresponding figures for mortality were 11.32/100 000, 8.35/100 000, 8.53/100 000, and 1.04%. The incidence and mortality increased with age between 40 and 80 years. The rates in rural dwellers, especially men, showed negative APC (−13.25% vs. −11.08%; P < 0.05).

Conclusions

The incidence and mortality rates of esophageal cancer in Inner Mongolia increased between 2010 and 2015. The rates were higher in men in rural areas, middle‐aged and elderly individuals. Prevention and control programs focused on these groups, in addition to early diagnosis and treatment of esophageal cancer, are needed to reduce these rates.

Key points

Significant findings of the study: In Inner Mongolia, incidence and mortality rates of esophageal cancer were higher in urban areas than in rural areas and in men than in women between 2010 and 2015, and in middle‐aged and elderly than in younger people.

What this study adds: Prevention and control programs, in addition to early diagnosis and treatment of esophageal cancer, should be tailored to specifically target men in rural areas and middle‐aged and elderly individuals in order to reduce the incidence and mortality rates of this pathology.

Emergence of neural regulatory mechanisms in carcinogenesis

Emerging data indicate that the nervous system plays an important role in carcinogenesis. However, more studies are required to help further elucidate the mechanisms involved in the neural regulation of carcinogenesis. Some recent findings describing the neural regulatory mechanisms of action in prostate cancer, pancreatic cancer and hepatocellular carcinoma are discussed, with a focus on the sympathetic, parasympathetic, and sensory neuronal elements of the nervous system. Norepinephrine, which is released by the sympathetic nervous system and binds to the beta-adrenergic receptor, regulates cellular responses in both normal and tumor cells. It has also been shown that the destruction of sensory neurons can prevent or at least slow pancreatic cancer. Cortisol, the main stress hormone, is also discussed and how it could potentially be involved in hepatocellular carcinoma development. The importance of studying other signaling molecules in the nervous system, such as oxytocin and its receptor, the oxytocin receptor, and how they might be involved in carcinogenesis when aberrantly expressed is highlighted. This is an area of study which clearly needs further investigation. A clearer understanding of the detailed mechanisms of how the nervous system is involved in carcinogenesis could potentially aid in the identification of novel biomarkers and development of novel preventative and therapeutic strategies in various cancers.

Androgen Receptor Promotes Gastric Carcinogenesis via Upregulating Cell Cycle-Related Kinase Expression

Gastric cancer (GC) is a leading global health problem as it is the fifth most common cancer type and the third most common cause of cancer-related deaths worldwide. In most areas of the world, the incidence rate of GC is 1.5- to 3-fold higher in males than in females. The androgen receptor (AR) is an independent adverse prognostic factor in patients with GC. However, the mechanism by which AR regulates the progression of GC remains unclear. In this study, we found that AR expression was upregulated in 6/8 GC cell lines, and this expression was higher than that in immortalized gastric cells. AR expression was also higher in GC tissues than in adjacent tissues. Moreover, the ectopic expression of AR promoted the colony formation ability, migration and invasion of GC cells. In contrast, AR knockdown had the opposite effects on GC cell lines. Remarkably, we found that AR regulated cell cycle-related kinase (CCRK) expression through transcriptional mechanisms. The AR-CCRK axis promoted GC development through the phosphorylation of GSK3β and β-catenin. Furthermore, TCGA data revealed that high expression of AR or CCRK was related to poor prognosis in GC patients. The prognosis was significantly worse in patients with concurrent high AR and CCRK expression than in patients with low AR and CCRK expression. In conclusion, our study demonstrated that AR and CCRK acted as oncogenes in GC progression. However, their clinical roles require further exploration.

Histopathological features of the proper gastric glands in FVB/N-background mice carrying constitutively-active aryl-hydrocarbon receptor

Background

Aryl-hydrocarbon receptor (AhR) is a multiple ligand-activated transcription factor that has important roles in xenobiotic, physiological, or pathological functions. Transgenic mice systemically expressing constitutively-active AhR (CA-AhR) have been created to mimic activated AhR signaling in vivo. However, their detailed histopathological features are unclear. In the present study, we generated CA-AhR-expressing FVB/N mice (FVB-CA-AhR mice) and clarified their phenotypes in detail.

Methods

Male and female FVB-CA-AhR and wild-type mice were histopathologically examined from 6 to 33 weeks of age.

Results

Among the systemic organs, only the stomachs in FVB-CA-AhR mice showed pathological changes including cystic structures beneath the serosa; in addition, stomach weights increased with age. Histopathologically, cystic structures and alcian blue-positive metaplasia were observed in the mucosa of the proper gastric glands, and these two histometric parameters were positively correlated. Furthermore, proliferating cells shifted from the isthmus to the base of the glands, and parietal cells decreased. Age-related histopathological changes were clearer in females than in males. Importantly, in FVB-CA-AhR mice, intramucosal cysts developed as extramucosal cysts beneath the serosa, penetrating the lamina muscularis mucosae and the muscularis propria. Their incidence reached 100% in 28-week-old male mice and 33-week-old female mice. Extramucosal cysts contained alcian blue-, Griffonia simplicifolia lectin II-, or trefoil factor 2-positive cells, suggesting a stomach origin for the cysts and spasmolytic polypeptide-expressing metaplasia-like lesions.

Conclusions

Disease onset occurred earlier in FVB-CA-AhR mice than previously reported in C57BL/6-derived CA-AhR mice. Importantly, the histopathological features were partly similar with gastritis cystica profunda in humans and animals. Excessive activation of AhR signaling aggravated abnormalities in the gastric mucosa and were affected by both genetic- and sex-related factors.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-1009-x) contains supplementary material, which is available to authorized users.

Mechanisms of hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been only minimal improvement in the prognosis for HCC patients over the past 15 years. Details of the molecular mechanisms and other mechanisms of HCC progression remain unclear. Consequently, there is an urgent need for better understanding of these mechanisms. HCC is often diagnosed at advanced stages, and most patients will therefore need systemic therapy, with sorafenib being the most common at the present time. However, sorafenib therapy only minimally enhances patient survival. This review provides a summary of some of the known mechanisms that either cause HCC or contribute to its progression. Included in this review are the roles of viral hepatitis, non-viral hepatitis, chronic alcohol intake, genetic predisposition and congenital abnormalities, toxic exposures, and autoimmune diseases of the liver. Well-established molecular mechanisms of HCC progression such as epithelial-mesenchymal transition, tumor-stromal interactions and the tumor microenvironment, cancer stem cells, and senescence bypass are also discussed. Additionally, we discuss the roles of circulating tumor cells, immunomodulation, and neural regulation as potential new mechanisms of HCC progression. A better understanding of these mechanisms could have implications for the development of novel and more effective therapeutic and prognostic strategies, which are critically needed.

Oxytocin and cancer: An emerging link

The neuropeptide hormone oxytocin, which is released from the posterior pituitary gland, is involved in a number of physiological processes. Understanding of its effects is gradually increasing due to new research in this area. While mostly recognized as a reproductive system hormone, oxytocin also regulates other organ systems such as the brain and cardiovascular system. Recently, research has focused on unraveling its involvement in cancer, and emerging evidence suggests a potential role for oxytocin as a cancer biomarker. This review summarizes observations linking oxytocin and cancer, with a special emphasis on prostate cancer, where it may promote cell proliferation. Research suggests that oxytocin effects may depend on cell type, concentration of the hormone, its interactions with other hormones in the microenvironment, and the precise localization of its receptor on the cell membrane. Future research is needed to further elucidate the involvement of oxytocin in cancer, and whether it could be a clinical cancer biomarker or therapeutic target.

Association of sporadic and familial Barrett's esophagus with breast cancer

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC). Based on striking aggregation of breast cancer and BE/EAC within families as well as shared risk factors and molecular mechanisms of carcinogenesis, we hypothesized that BE may be associated with breast cancer. Pedigree analysis of families identified prospectively at multiple academic centers as part of the Familial Barrett's Esophagus Consortium (FBEC) was reviewed and families with aggregation of BE/EAC and breast cancer are reported. Additionally, using a matched case-control study design, we compared newly diagnosed BE cases in Caucasian females with breast cancer (cases) to Caucasian females without breast cancer (controls) who had undergone upper endoscopy (EGD). Two familial pedigrees, meeting a stringent inclusion criterion, manifested familial aggregation of BE/EAC and breast cancer in an autosomal dominant inheritance pattern with incomplete penetrance. From January 2008 to October 2016, 2812 breast cancer patient charts were identified, of which 213 were Caucasian females who underwent EGD. Six of 213 (2.82%) patients with breast cancer had pathology-confirmed BE, compared to 1 of 241 (0.41%) controls (P-value < 0.05). Selected families with BE/EAC show segregation of breast cancer. A breast cancer diagnosis is marginally associated with BE. We postulate a common susceptibility between BE/EAC and breast cancer.

Flavan-3-ols consumption and cancer risk: A meta-analysis of epidemiologic studies

Although numerous in vitro studies and animal model data have suggested that flavan-3-ols, the most common subclass of flavonoids in the diet, may exert protective effects against cancer, epidemiologic studies have reported inconclusive results for the association between flavan-3-ols intake and cancer risk. Therefore, we conducted this meta-analysis of epidemiologic studies to investigate the preventive effects of flavan-3-ols on various types of cancers. A total of 43 epidemiologic studies, consisting of 25 case-control and 18 prospective cohort studies, were included. A significant inverse association was shown between flavan-3-ols intake and the risk of overall cancer (relative risk (RR) 0.935, 95%CI: 0.891-0.981). When cancer types were separately analyzed, a statistically significant protective effect of flavan-3-ols consumption was observed in rectal cancer (RR 0.838, 95%CI: 0.733-0.958), oropharyngeal and laryngeal cancer (RR 0.759, 95%CI: 0.581-0.993), breast (RR 0.885, 95%CI: 0.790-0.991) in case-control studies and stomach cancer in women (RR 0.633, 95%CI: 0.468-0.858). Our analysis indicates the potential benefits of flavan-3-ols in cancer prevention.

Effects of Estrogen on the Gastrointestinal Tract

Estrogen is a kind of steroid compound that has extensive biologic activities. The effect of estrogen is pleiotropic, affecting multiple systems in the body. There is accumulating evidence that estrogen has important effects on the gastrointestinal tract. Longer exposure to estrogen may decrease the risk of gastric cancer. Use of the anti-estrogen drug tamoxifen might increase the risk of gastric adenocarcinoma. Estrogen receptor β may serve as a target for colorectal cancer prevention. In addition, estrogen has been reported to be closely related to the mucosal barrier, gastrointestinal function and intestinal inflammation. However, the role of estrogen in the gastrointestinal tract has not been systematically summarized. In this review, we aim to provide an overview of the role of estrogen in the gastrointestinal tract and evaluate it from various aspects, including estrogen receptors, the mucosal barrier, intestinal inflammation and gastrointestinal tract tumors, which may provide the basis for the development of therapeutic strategies to manage gastrointestinal diseases.

Selective oestrogen receptor antagonists inhibit oesophageal cancer cell proliferation in vitro

BACKGROUND

Oestrogen receptors (ER) have a well-established role to the initiation, progression and regulation of responses to treatment of breast, prostate, and lung cancers. Previous data indicates altered ER expression in oesophageal cancers (OC). However the role of ER subtypes and ER specific inhibitors in the regulation of OC progression remains unclear. This study sought to assess levels of ERα and ERβ in OC. The effects of highly selective ER antagonists on cell proliferation and apoptosis in two OC adenocarcinoma cell lines was also studied.

METHODS

ERα and ERβ expression profiling in paired normal oesophageal mucosa and tumour tissues (n = 34; adenocarcinoma n = 28; squamous cell carcinoma n = 6) was performed using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Correlation between levels of ER with the clinico-pathological features for OC was determined. The effect of selective ER antagonists on proliferation of OE33 and OE19 OC cell lines was studied.

RESULTS

ERα and ERβ mRNA expression was significantly higher (p < 0.05) in tumour tissues relative to their paired normal mucosa and correlated inversely with survival outcome (p < 0.05). Upregulation of ERα mRNA correlated with higher pathological T-stage (p < 0.05) and lymph node metastasis (p < 0.05) while ERβ mRNA upregulation correlated with positive vascular invasion (p < 0.05). A significant concentration-dependent inhibition of proliferation in OE33 and OE19 cell lines was induced by a highly-selective ERα antagonist (MPP) and an ERβ specific antagonist (PHTPP) (p < 0.05). Moreover, anti-oestrogens induced cell death through stimulation of apoptotic caspase activity.

CONCLUSION

These findings indicate that the ER system is involved in OC progression and thus may provide a novel target for the treatment of OC.

Global trends in esophageal cancer

BACKGROUND AND OBJECTIVES

Esophageal Cancer (EC) is a lethal malignancy with poor prognosis and significant variations in the incidence, mortality, and histopathology based on geographic regions. The aim of this study was to quantitatively analyze these variations to identify patterns and areas for further research.

METHODS

We utilized the GLOBOCAN 2012, and Cancer Incidence in five Continents, Volume X (CI5X) database to analyze variations in EC incidence and mortality.

RESULTS

We found the EC incidence and mortality is geographically varied with a particularly high burden in East Asia and Eastern/Southern Africa where esophageal squamous cell carcinoma (SCC) predominates over adenocarcinoma (AC). Interestingly, there is a dichotomy between the high incidence of esophageal SCC in East Africa and low incidence in West Africa. The global incidence and mortality from EC is expected to rise in the coming decades. Asia, and China in particular, will continue to be the areas most burdened by EC, while Africa is expected to surpass the incidence and mortality rates of Europe.

CONCLUSIONS

The global burden of EC is expected to rise in the coming years. Understanding the geographic, environmental, and genetic contributors to the development of EC will be essential in combating its prevalence.

Hormonal and reproductive factors and risk of esophageal cancer in women: a meta-analysis

Currently published studies on the relationship between hormonal and reproductive factors and esophageal cancer (EC) risk in women have yielded contradictory findings. For a better understanding of this relationship, we first performed this meta-analysis by pooling all available publications. Sixteen independent studies were retrieved after a comprehensive search in PubMed and Embase databases. The pooled relative risks (RRs) with 95% confidence intervals (95% CIs) were calculated. The pooled RRs implicated that hormone replacement therapy was negatively associated with the risk of EC (RR = 0.72, 95% CI 0.60-0.86, P < 0.001) and esophageal squamous cell carcinoma (RR = 0.68, 95% CI 0.48-0.97, P = 0.031). Menopausal women were at an increased risk of EC (RR = 1.47, 95% CI 1.07-2.03, P = 0.018), particularly esophageal squamous cell carcinoma (RR = 1.66, 95% CI 1.12-2.48, P = 0.012). Additionally, decreased risk of EC (RR = 0.79, 95% CI 0.68-0.92, P = 0.003) and esophageal adenocarcinoma (RR = 0.66, 95% CI 0.53-0.82, P < 0.001) was demonstrated among women with breast-feeding history. Moreover, such associations were more significant among Caucasians, but not Asians. Our study suggests that menopause is an independent risk factor for EC, while hormone replacement therapy and breast-feeding history play a protective role against EC, particularly among Caucasians. All results are consistent with the hypothesis that effects of estrogen may lower the risk of EC in women.

The Male Predominance in Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased rapidly during the past 4 decades in many Western populations, including North America and Europe. The established etiological factors for EAC include gastroesophageal reflux and obesity, Helicobacter pylori infection, tobacco smoking, and consumption of fruit and vegetables. There is a marked male predominance of EAC with a male-to-female ratio in incidence of up to 9:1. This review evaluates the available literature on the reasons for the male predominance, particularly an update on epidemiologic evidence from human studies during the past decade. The striking sex difference does not seem to be explained by established risk factors, given that the prevalence of the etiological factors and the strengths of associations between these factors and EAC risk are similar between the sexes. Sex hormonal factors may play a role in the development of EAC; estrogenic exposures may prevent such development, whereas androgens might increase the risk of EAC. However, continuing research efforts are still needed to fully understand the reasons for the male predominance of EAC.

Association between circulating levels of sex steroid hormones and Barrett's esophagus in men: a case-control analysis

BACKGROUND & AIMS

Esophageal adenocarcinoma is believed to result from the progression of gastroesophageal reflux disease to erosive esophagitis and re-epithelialization of the esophagus with a columnar cell population termed Barrett's esophagus (BE). Men develop BE and esophageal adenocarcinoma more frequently than women, yet little is known about the mechanisms of this difference. We assessed whether sex steroid hormones were associated with BE in a male population.

METHODS

We analyzed data from the Barrett's Esophagus Early Detection Case Control Study, based at the Walter Reed National Military Medical Center. Blood samples were collected from 174 men with BE and 213 men without BE (controls, based on endoscopic analysis); 13 sex steroid hormones were measured by mass spectrometry and sex hormone binding globulin was measured by enzyme-linked immunosorbent assay. We also calculated free estradiol, free testosterone, and free dihydrotestosterone (DHT). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age, race, smoking status, alcohol consumption, body mass index, heartburn, regurgitation, and gastroesophageal symptom score (excluding heartburn and regurgitation).

RESULTS

Levels of free testosterone and free DHT were associated positively with BE risk; patients in the highest quartile for these hormones were most likely to have BE (free testosterone: OR, 5.36; 95% CI, 2.21-13.03; P = .0002; free DHT: OR, 4.25; 95% CI, 1.87-9.66; P = .001). Level of estrone sulfate was associated inversely with BE risk (P for trend = .02). No other hormone was associated with BE risk. Relationships were not modified by age or BMI.

CONCLUSIONS

In an analysis of men, levels of free testosterone and free DHT were significantly associated with BE.

Is hormone replacement therapy in post-menopausal women associated with a reduced risk of oesophageal cancer?

PURPOSE

The rise in oesophageal adenocarcinoma incidence in women with age is delayed compared with men until the post-menopausal period. A matched cohort study was therefore undertaken of post-menopausal women on hormone replacement therapy (HRT) to examine the association between HRT, oesophageal cancer and the potentially associated conditions, reflux oesophagitis and Barrett's oesophagus.

METHODS

Women aged over 50 years within the UK General Practice Research Database with a history of HRT exposure were matched by age and general practice with controls without HRT exposure (1:1). Matched Cox-regression analysis was performed to estimate adjusted hazard ratios.

RESULTS

51,851 HRT users and controls were studied. Prolonged HRT use for 5-10 years (hazard ratio 0.25 (95% CI 0.07-0.95)) and time-dependent covariates for increasing duration of HRT use (0.06 (0.01-0.43)) were associated with a reduced oesophageal cancer risk. HRT use was associated with reflux oesophagitis (1.27 (1.12-1.43)), but when analysis was confined to women with codes for both reflux oesophagitis and endoscopy there was no association (1.1 (0.81-1.44)), suggesting increased reporting of reflux symptoms among HRT users rather than an association with endoscopic reflux oesophagitis.

CONCLUSION

Long-term post-menopausal HRT may be associated with a reduced risk of oesophageal cancer.

17β-Estradiol inhibition of IL-6-Src and Cas and paxillin pathway suppresses human mesenchymal stem cells-mediated gastric cancer cell motility

Epidemiological studies demonstrate that the incidence and mortality of gastric cancer in women are lower than in men worldwide. Many studies have reported the delayed menopause and hormone replacement therapy are associated with a reduced risk for gastric cancer. It has been reported that endogenous estrogen lowers gastric cancer incidence in women, and cancer patients treated with estrogens have a lower subsequent risk of gastric cancer. It has been reported that estrogen decreases the progression of gastric cancer by inhibiting erbB-2 oncogene expression. Overexpression of estrogen receptor might inhibit the proliferation and invasion of MKN28 gastric cancer cells. Accumulating evidence suggests that bone marrow mesenchymal stem cells contribute to the progression of gastric cancer. However, it is unknown if 17β-estradiol (E2) treatment is sufficient to inhibit human bone marrow mesenchymal stem cells (HBMMSCs)-mediated cell motility in human gastric cancer cells. The results from human cytokine arrays have shown that HBMMSCs notably secrete interleukin 6 (IL-6) protein. Administration of IL-6-specific neutralizing antibody significantly inhibits HBMMSCs-mediated motility activity in human gastric cancer cells. Treatment of recombinant IL-6 soluble protein confirmed the role of IL-6 in mediating HBMMSCs-upregulated cell motility. IL-6 mainly upregulates motility activity via activation of Src signaling pathway in human gastric cancer cells. We further observed that E2 treatment inhibits HBMMSCs-induced cellular motility via suppressing the activation of IL-6-Src/Cas/paxillin signaling pathway in human gastric cancer cells. Collectively, these results suggest that E2 treatment significantly inhibits HBMMSCs-induced cellular motility in human gastric cancer cells.

Oxytocin has therapeutic effects on cancer, a hypothesis

Oxytocin (OT) is the first peptide hormone structurally assessed and chemically synthesized in biologically active form. This hormone acts as an important factor in a human reproductive system particularly during pregnancy and lactation in women. So far, different therapeutic roles for OT have been identified as a spectrum from central and peripheral actions on male and female reproductive systems, circulatory system, musculoskeletal system, etc. Some in vitro and in vivo studies also revealed that OT is responsible for bivariate biological functions involved in cancer as following. By activating OT receptor in tumoral cells, OT enacts as a growth regulator, whether activator or inhibitor. Regarding the increase of OT in some conditions such as breastfeeding, exercise, and multiparity, we can relate the effect of these conditions on cancer with OT effects. Based on this hypothesis, we present a review on the effects of this neuropeptide on various types of cancer and also the influence of these conditions on the same cancer.

Chronic tamoxifen use is associated with a decreased risk of intestinal metaplasia in human gastric epithelium

BACKGROUND

Intestinal metaplasia (IM), a premalignant lesion, is associated with an increased risk of gastric cancer. Although estrogen exposure, including tamoxifen, has been studied in correlation with gastric cancer, little has been investigated about its effects on IM.

AIMS

Therefore, we investigated whether chronic tamoxifen use was associated with the risk of IM in human stomach.

METHODS

We evaluated 512 gastric biopsies from 433 female breast cancer patients that underwent endoscopic gastroduodenoscopy (EGD) ≥6 months after breast surgery. Histopathological findings were scored according to the updated Sydney classification. Demographic and clinical characteristics were also included to identify predictive factors for IM.

RESULTS

In a multivariate logistic regression analysis, age at EGD (odds ratio [OR], 1.04; P = 0.002), biopsies from antrum (OR 2.08; P < 0.001), and Helicobacter pylori positivity (OR 1.68; P = 0.016) were significantly associated with an increased risk of IM, whereas chronic tamoxifen use (≥3 months) was associated with a decreased risk of IM (OR 0.59; P = 0.025). After stratifying by biopsy site, association between tamoxifen use and IM persisted for corpus (OR 0.42; P = 0.026) but not for antrum (OR 0.74; P = 0.327). In analysis limited to patients with follow-up EGD, chronic tamoxifen use also correlated with improved IM score compared to no tamoxifen use (improved, 77.8 vs. 22.2%; no change, 65.4 vs. 34.6%; worsened, 30.0 vs. 70.0%; P = 0.019).

CONCLUSIONS

This study suggests that chronic tamoxifen use can decrease the risk of IM in human stomach. The effect of tamoxifen is predominantly observed in the corpus.

Hormone replacement therapy and oral contraceptives and risk of oesophageal adenocarcinoma: a systematic review and meta-analysis

There is an unexplained strong male predominance in the aetiology of oesophageal adenocarcinoma (OAC). The hypothesis that oestrogens are protective, deserves attention. A potential protective influence of exogenous oestrogen exposure, that is, hormone replacement therapy (HRT) and oral contraceptives (OC) has been addressed only in studies of limited statistical power, and the individual studies have not provided conclusive results. We conducted a systematic literature search and meta-analysis on HRT and OC and the risk of OAC. We used the databases PubMed and the Web of Science. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by the Mantel-Haenszel random-effect method. A total of five studies were included. Compared to never users, ever users of HRT had a statistically significantly decreased risk of OAC (pooled OR = 0.75; 95% CI: 0.58-0.98), and ever users of OC had a borderline significantly decreased risk of this cancer (pooled OR = 0.76; 95% CI: 0.57-1.00). In conclusion, HRT and OC use seems to be associated with a decreased risk of OAC. However, further research is warranted.

17β-estradiol inhibits mesenchymal stem cells-induced human AGS gastric cancer cell mobility via suppression of CCL5- Src/Cas/Paxillin signaling pathway

Gender differences in terms of mortality among many solid organ malignancies have been proved by epidemiological data. Estrogen has been suspected to cast a protective effect against cancer because of the lower mortality of gastric cancer in females and the benefits of hormone replacement therapy (HRT) in gastric cancer. Hence, it suggests that 17β-estradiol (E2) may affect the behavior of cancer cells. One of the key features of cancer-related mortality is metastasis. Accumulating evidences suggest that human bone marrow mesenchymal stem cells (HBMMSCs) and its secreted CCL-5 have a role in enhancing the metastatic potential of breast cancer cells. However, it is not clear whether E2 would affect HBMMSCs-induced mobility in gastric cancer cells. In this report, we show that CCL-5 secreted by HBMMSCs enhanced mobility in human AGS gastric cancer cells via activation of Src/Cas/Paxillin signaling pathway. Treatment with specific neutralizing antibody of CCL-5 significantly inhibited HBMMSCs-enhanced mobility in human AGS gastric cancer cells. We further observe that 17β-estradiol suppressed HBMMSCs-enhanced mobility by down-regulating CCL5-Src/Cas/paxillin signaling pathway in AGS cells. Collectively, these results suggest that 17β-estradiol treatment significantly inhibits HBMMSCS-induced mobility in human AGS gastric cancer cells.

Overexpression of ERα inhibits proliferation and invasion of MKN28 gastric cancer cells by suppressing β-catenin

The relationship between estrogen receptor (ER)α and patient prognosis has been identified in gastric cancer; however, the definite role of ERα in gastric cancer remains to be fully elucidated. The aim of the present in vitro study was to investigate the impact of ERα on cell proliferation, migration and invasion in gastric cancer cell lines. We investigated the biological effect of ERα overexpression on gastric carcinoma cells. An MKN28 gastric cancer cell line stably overexpressing ERα was established. The effect of ERα overexpression on cell growth was assessed by evaluating cell survival, colony formation, cell cycle progression and apoptosis. Cell migration and invasion were detected by Transwell migration/invasion assays. The protein levels of several potentially involved genes were determined by western blotting to elucidate the underlying molecular mechanisms. The Student's t-test was used to determine the statistical differences between various experimental and control groups, and one-way ANOVA test was used to determine the difference between three or more groups. The results showed that ERα overexpression significantly inhibited cell growth and proliferation, blocked cell entry into the G1/G0 phase and promoted cell apoptosis. In addition, ERα reduced the motility and invasion of gastric cancer cells. These phenotypes may partly be explained by a decrease in β-catenin expression caused by ERα overexpression. ERα overexpression effectively inhibited cell growth and cancer progression by suppressing β-catenin in gastric cancer, identifying ERα as a promising target with therapeutic potential for development of new approaches to treat gastric cancer.

ER-α36-mediated gastric cancer cell proliferation via the c-Src pathway

Previously, a novel variant of estrogen receptor (ER)-α, ER-α36, was identified and cloned and reported to mainly mediate non-genomic estrogen signaling. More recently, we identified that ER-α36 is important for the invasion and lymph node metastasis of human gastric cancer. In the present study, the c-Src signaling pathway was demonstrated to be involved in the non-genomic estrogen signaling mediated by ER-α36 in SGC7901 gastric cancer cells. SGC7901 cells were subjected to the siRNA-mediated knockdown of ER-α36 (PLKO.1-PURO-SP6-ER-α36-L) or transfected with an ER-α36 upregulated expression plasmid (PLJM1-ER-α36-H) and treated with 17β-estradiol (E2β) and PP2, a c-Src protein inhibitor. The expression of ER-α36 and c-src/p-c-Src and cyclin D1 was examined by western blot analysis, and tumor cell growth was analyzed by cell proliferation and nude mouse xenograft assays. The ER variant, ER-α36, was shown to enhance gastric cancer cell proliferation through activation of the membrane-initiated c-Src signaling pathways, indicating that ER-α36 is important for the regulation of proliferation in gastric cancer. In addition, ER-α36 was shown to directly interact with c-Src by immunoprecipitation. The results of the present study indicate that the use of ER-α36 may be a targeted therapeutic approach in gastric cancer.

PDIp is a major intracellular oestrogen-storage protein that modulates tissue levels of oestrogen in the pancreas

E(2) (17β-oestradiol), a female sex hormone, has important biological functions in a woman's body. The pancreas, often considered a non-classical E(2)-targeting organ, is known to be functionally regulated by E(2), but little is known about how oestrogen actions are regulated in this organ. In the present study we report that PDIp (pancreas-specific protein disulfide isomerase), a protein-folding catalyst, can act as a major intracellular E(2) storage protein in a rat model to modulate the pancreatic tissue level, metabolism and action of E(2). The purified endogenous PDIp from both rat and human pancreatic tissues can bind E(2) with a K(d) value of approximately 150 nM. The endogenous PDIp-bound E(2) accounts for over 80% of the total protein-bound E(2) present in rat and human pancreatic tissues, and this binding protects E(2) from metabolic disposition and prolongs its duration of action. Importantly, we showed in ovariectomized female rats that the E(2) level in the pancreas reaches its highest level (9-fold increase over its basal level) at 24-48 h after a single injection of E(2), and even at 96 h its level is still approximately 5-fold higher. In contrast, the E(2) level in the uterus quickly returns to its basal level at 48 h after reaching its maximal level (approximately 2-fold increase) at 24 h. Taken together, these results show for the first time that PDIp is a predominant intracellular oestrogen storage protein in the pancreas, which offers novel mechanistic insights into the accumulation and action of oestrogen inside pancreatic cells.

Why is there a change in patterns of GE cancer?

Recent decades have seen a worrying trend in incidence rates of distal oesophageal and proximal gastric cancers. Fuelled by radical changes in lifestyle, diet, physical activity and environmental exposures, as well as an ageing population and host genetic predisposition, the incidence of oesophageal adenocarcinoma (OAC) is on the rise in Western populations. While overall incidence of gastric cancers is declining, the ageing of society means that an increase in absolute numbers is expected over coming years. Both cancers tend to present at an advanced stage, hence prognosis remains poor despite increasingly effective screening and treatment strategies. The development of gastric and oesophageal malignancies is influenced by myriad factors, not least geographical, racial and socioeconomic differences in addition to lifestyle choices. The multidimensional nature of these risk factors requires a holistic understanding of their net influence in the development of malignancy. This review explores the evidence base for established and putative risk factors in the development of gastric and oesophageal cancers. It is hoped that with a clear understanding of important risk factors, a multidisciplinary approach including effective primary prevention, regular screening of high-risk groups and continued research into the molecular biology of gastrointestinal carcinogenesis may facilitate a reduction in incidence rates, as well as early detection and optimal management of upper gastrointestinal malignancies.

Genetic susceptibility factors on genes involved in the steroid hormone biosynthesis pathway and progesterone receptor for gastric cancer risk

Background

The objective of the study was to investigate the role of genes (HSD3B1, CYP17A1, CYP19A1, HSD17B2, HSD17B1) involved in the steroid hormone biosynthesis pathway and progesterone receptor (PGR) in the etiology of gastric cancer in a population-based two-phase genetic association study.

Methods

In the discovery phase, 108 candidate SNPs in the steroid hormone biosynthesis pathway related genes and PGR were analyzed in 76 gastric cancer cases and 322 controls in the Korean Multi-Center Cancer Cohort. Statistically significant SNPs identified in the discovery phase were re-evaluated in an extended set of 386 cases and 348 controls. Pooled- and meta-analyses were conducted to summarize the results.

Results

Of the 108 SNPs in steroid hormone biosynthesis pathway related genes and PGR analyzed in the discovery phase, 23 SNPs in PGR in the recessive model and 10 SNPs in CYP19A1 in the recessive or additive models were significantly associated with increased gastric cancer risk (p<0.05). The minor allele frequencies of the SNPs in both the discovery and extension phases were not statistically different. Pooled- and meta-analyses showed CYP19A1 rs1004982, rs16964228, and rs1902580 had an increased risk for gastric cancer (pooled OR [95% CI] = 1.22 [1.01–1.48], 1.31 [1.03–1.66], 3.03 [1.12–8.18], respectively). In contrast, all PGR SNPs were not statistically significantly associated with gastric cancer risk.

Conclusions

Our findings suggest CYP19A1 that codes aromatase may play an important role in the association of gastric cancer risk and be a genetic marker for gastric cancer susceptibility.

Dietary intake of lignans and risk of adenocarcinoma of the esophagus and gastroesophageal junction

PURPOSE

The strong male predominance in esophageal and gastroesophageal junctional adenocarcinoma remains unexplained. Sex hormonal influence has been suggested, but not proven. A protective role of dietary phytoestrogen lignans was hypothesized.

METHODS

A Swedish nationwide population-based case-control study was conducted in 1995-1997, including 181 cases of esophageal adenocarcinoma, 255 cases of gastroesophageal junctional adenocarcinoma, 158 cases of esophageal squamous cell carcinoma, and 806 control subjects. Data on various exposures, including dietary data, were collected through personal interviews and questionnaires. Dietary intake of lignans was assessed using a food frequency questionnaire and categorized into quartiles based on the consumption among the control participants. Unconditional logistic regression was used to calculate odds ratios (ORs) with 95 % confidence intervals (CIs), including adjustment for all established risk factors.

RESULTS

Participants in the highest quartile of intake of lignans compared with the lowest quartile were at a decreased risk of esophageal adenocarcinoma (OR, 0.65; 95 % CI, 0.38-1.12; p for trend =0.03), gastroesophageal junctional adenocarcinoma (OR, 0.37; 95 % CI, 0.23-0.58; p for trend <0.0001), and these adenocarcinomas combined (OR, 0.45; 95 % CI, 0.31-0.67; p for trend <0.0001). No clear associations were found between lignan intake and risk of esophageal squamous cell carcinoma.

CONCLUSIONS

This population-based study indicates that a high dietary intake of lignans decreases the risk of adenocarcinoma of the esophagus and gastroesophageal junction.

Estrogen upregulates the IGF-1 signaling pathway in lung cancer through estrogen receptor-β

The estrogen receptor (ER) signaling and the insulin-like growth factor-1 receptor (IGF-1R) signaling are implicated in lung cancer progression. Here, we sought to investigate whether estrogen regulated the IGF-1R signaling in non-small cell lung cancer (NSCLC) and the underlying mechanisms. We examined and analyzed the correlation of the expression of aromatase (Arom), ERβ, ERα, insulin-like growth factor-1 (IGF-1), and IGF-1R in NSCLC. Tissue-microarray and immunohistochemistry analysis of tissue specimens from 162 NSCLC patients and 38 patients with benign pulmonary lesions showed that Arom, ERβ, IGF-1, and IGF-1R were overexpressed while ERα was not expressed in NSCLC. Furthermore, ERβ expression was positively correlated with that of Arom, IGF-1, and IGF-1R (r=0.554, 0.649, 0.496, respectively, P values are equal to 0.000), while Arom expression was positively associated with that of IGF-1 and IGF-1R (r=0.657, 0.714, respectively, P values are equal to 0.000). Additionally, ERβ, IGF-1, and phospho-IGF-1R, but not ERα, were expressed in A549 cells. Immunoblotting assays showed that A549 cells treated with E2 showed significantly higher IGF-1 and p-IGF-1R levels than those receiving the combination treatment of 17β-estradiol (E2) and fulvestrant (Ful, ER antagonist) (P=0.042, 0.002, respectively) or controls (P values are equal to 0.000). The MTT assays further revealed that E2 and IGF-1 synergistically promoted A549 cell proliferation. Together, our study provides the first direct evidence for an interaction between ER and IGF-1R in lung cancer. We showed that estrogen upregulated the IGF-1R signaling through ERβ in lung cancer tissues and A549 cells. These findings shed further light on the mechanisms whereby estrogen promotes lung cancer and highlight the ER and IGF-1R signaling pathways as promising targets for combinational therapy for lung cancer.

Estrogen, male dominance and esophageal adenocarcinoma: is there a link?

Esophageal adenocarcinoma is a cancer with poor prognosis, and its incidence has risen sharply over recent decades. Obesity is a major risk factor for developing this cancer and there is a clear male gender bias in the incidence that cannot be fully explained by known risk factors. It is possible that a difference in the expression of estrogen, or its signaling axes, may contribute to this gender bias. We undertook a comprehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expression, and the possible sex-specific links with esophageal adenocarcinoma development. Potentially relevant associations between visceral vs subcutaneous fat deposition and estrogen expression, and the effect of crosstalk between estrogen and leptin signaling were identified. We also found limited studies suggesting a role for estrogen receptor β expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcinoma, but further studies are required.

Isoflavone intake and risk of gastric cancer: a population-based prospective cohort study in Japan

BACKGROUND

Isoflavones are structurally similar to 17β-estradiol and may be able to prevent gastric cancer. However, there is contradictory evidence concerning the relation between the intake of soy food, which is rich in isoflavones, and gastric cancer. The association with gastric cancer might differ between isoflavones and soy foods, and research on the effects of isoflavone intake alone on gastric cancer is needed.

OBJECTIVE

We investigated the association between isoflavone intake and the incidence of gastric cancer.

DESIGN

We conducted a large, population-based prospective study of 39,569 men and 45,312 women aged 45-74 y. Dietary soy and isoflavone intakes were measured by using a validated food-frequency questionnaire in 1995 and 1998.

RESULTS

During 806,550 person-years of follow-up, we identified 1249 new gastric cancer cases. Isoflavone intake was not associated with gastric cancer in either men or women. Compared with the lowest quartile, the HR and 95% CI for developing gastric cancer in the fourth quartile of isoflavone intake was 1.00 (0.81, 1.24) for men and 1.07 (0.77, 1.50) for women. In a stratified analysis by exogenous female hormones (women only), however, we found an increasing trend in risk of gastric cancer associated with higher isoflavone intakes among exogenous female hormone users (P-trend = 0.03) but not for nonusers (P-interaction = 0.04).

CONCLUSION

The current study does not support the hypothesis that higher intakes of isoflavones prevent gastric cancer in either men or women.

Sex hormones, hormonal interventions, and gastric cancer risk: a meta-analysis

Estrogens may influence gastric cancer risk, but published studies are inconclusive. We therefore carried out a meta-analysis addressing the associations of gastric cancer in women with menstrual and reproductive factors and with use of estrogen- and antiestrogen-related therapies. Searches of PubMed up to June, 2011 and review of citations yielded a total of 28 independent studies, including at least one exposure of interest. Random effects pooled estimates of relative risk (RR) and corresponding 95% CIs were calculated for eight exposures reported in at least five studies, including: age at menarche, age at menopause, years of fertility, parity, age at first birth, oral contraceptive use, hormone replacement therapy (HRT), and tamoxifen treatment. Longer years of fertility (RR = 0.74, 95% CI: 0.63-0.86) and HRT (RR = 0.77; 95% CI: 0.64-0.92) were each associated with decreased gastric cancer risk. Conversely, tamoxifen treatment was associated with increased risk (RR = 1.82; 95% CI: 1.39-2.38). The other five exposures were not significantly associated. Our analysis supports the hypothesis that longer exposure to estrogen effects of either ovarian or exogenous origin may decrease risk of gastric cancer. Additional studies are warranted to extend this finding and to identify the underlying mechanisms.

Cyclin D1/cdk4, estrogen receptors α and β, in N-methyl-N'-nitro-N-nitrosoguanidine-induced rat gastric carcinogenesis: immunohistochemical study

Hyperproliferative cell growth due to cyclin D1/cdk4, marker of cellular proliferation, is considered to be regulated by the expression of estrogen receptors (ERs). We investigated the immunohistochemical expression of cyclin D1/cdk4 and ERs in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced rat gastric carcinogenesis. The gastric cancer incidence and expression of cyclin D1/ckd4 in gastric carcinogenesis were significantly higher in males than females. Although the ERα expression index was similar in both sexes, the ERβ expression in preneoplastic hyperplastic lesions as well as gastric cancers was significantly higher in females than in males. The present study revealed a gender difference in MNNG-induced rat gastric carcinogenesis that seemed to involve the sex difference in cyclin D1/cdk4 expression, and ERβ expression became evident at the preneoplastic promotion stage in gastric carcinogenesis.

Menopausal hormone therapy and risk of gastrointestinal cancer: nested case-control study within a prospective cohort, and meta-analysis

Use of menopausal hormone therapy (HT) has been associated with reduced risk of colorectal cancer; evidence for its effect on other gastrointestinal cancers is limited. We conducted a nested case-control study within a UK cohort, and meta-analyses combining our results with those from published studies. Our study included women aged 50+ in the UK General Practice Research Database (GPRD): 1,054 with oesophageal, 750 with gastric and 4,708 with colorectal cancer, and 5 age- and practice-matched controls per case. Relative risks (RRs) and 95% confidence intervals (CIs) for cancer in relation to prospectively-recorded HT prescriptions were estimated by conditional logistic regression. Women prescribed HT had a reduced risk of oesophageal cancer (adjusted RR for 1+ vs. no HT prescriptions, 0.68, 95% CI 0.53-0.88; p = 0.004), gastric cancer (0.75, 0.54-1.05; p = 0.1) and colorectal cancer (0.81, 0.73-0.90; p < 0.001). There were no significant differences in cancer risk by HT type, estimated duration of HT use or between past and current users. In meta-analyses, risks for ever vs. never use of HT were significantly reduced for all three cancers (summary RR for oesophageal cancer, 0.68, 0.55-0.84, p < 0.001; for gastric cancer, 0.78, 0.65-0.94, p = 0.008; for colorectal cancer, 0.84, 0.81-0.88, p < 0.001). In high-income countries, estimated incidence over 5 years of these three cancers combined in women aged 50-64 was 2.9/1,000 in HT users and 3.6/1,000 in never users. The absolute reduction in risk of these cancers in HT users is small compared to the HT-associated increased risk of breast cancer.

Chemoprevention of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in Western countries, and effective chemoprevention for this malignancy is lacking. Endoscopic surveillance of patients with Barrett's esophagus is currently employed to diagnose EAC at earlier stages, but this strategy has several limitations. Non-steroidal anti-inflammatory drugs and proton pump inhibitors are the most promising agents for prevention of EAC, and a randomized controlled trial of aspirin and esomeprazole is ongoing. Other agents under investigation include green tea, berries, and antioxidants. Cost-effectiveness analyses have shown that chemopreventive agents need to be highly effective at preventing EAC in order to have benefit beyond endoscopic surveillance.

17 β-estradiol suppresses Helicobacter pylori-induced gastric pathology in male hypergastrinemic INS-GAS mice

Helicobacter pylori-associated gastric cancer is male predominant and animal studies suggest that sex hormones influence gastric carcinogenesis. We investigated the effects of 17β-estradiol (E2) or castration on H.pylori-induced gastritis in male INS-GAS/FVB/N (Tg(Ins1-GAS)1Sbr) mice. Comparisons were made to previously evaluated sham (n = 8) and H.pylori-infected (n = 8), intact male INS-GAS mice which had developed severe corpus gastritis accompanied by atrophy, hyperplasia, intestinal metaplasia and dysplasia of the epithelium within 16 weeks postinfection (all P < 0.01). Castration at 8 weeks of age had no sparing effect on lesions in uninfected (n = 5) or H.pylori-infected mice (n = 7) but all lesion subfeatures were attenuated by E2 in H.pylori-infected mice (n = 7) (P < 0.001). Notably, inflammation was not reduced but glandular atrophy, hyperplasia, intestinal metaplasia and dysplasia were also less severe in uninfected, E2-treated mice (n = 7) (P < 0.01). Attenuation of gastric lesions by E2 was associated with lower messenger RNA (mRNA) expression of interferon (IFN)-γ (P < 0.05) and interleukin (IL)-1β (P < 0.004), and higher IL-10 (P < 0.02) as well as decreased numbers of Foxp3(+) regulatory T cells when compared with infected intact males. Infected E2-treated mice also developed higher Th2-associated anti-H.pylori IgG1 responses (P < 0.05) and significantly lower Ki-67 indices of epithelial proliferation (P < 0.05). E2 elevated expression of mRNA for Foxp3 (P < 0.0001) and IL-10 (P < 0.01), and decreased IL-1β (P < 0.01) in uninfected, intact male mice compared with controls. Therefore, estrogen supplementation, but not castration, attenuated gastric lesions in H.pylori-infected male INS-GAS mice and to a lesser extent in uninfected mice, potentially by enhancing IL-10 function, which in turn decreased IFN-γ and IL-1β responses induced by H.pylori.

The influence of age, sex, and race on the incidence of esophageal cancer in the United States (1992-2006)

BACKGROUND

There is a striking male predominance in esophageal cancer patients. Sex hormones have been suggested as a contributing factor and these are influenced by age and race. In this study, we examined the male-to-female incidence rate ratios of esophageal cancer in the United States.

METHODS

We used data from 13 registries in the Surveillance, Epidemiology, and End Results (SEER) database to calculate male-to-female incidence rate ratios of esophageal adenocarcinoma (EA) and esophageal squamous cell carcinoma (ESCC) diagnosed during 1992-2006 in different age and race groups.

RESULTS

For EA, all races had similar sex and age-specific incidence patterns showing a peak in the male-to-female incidence rate ratio in the age group 50-59, and an age-related decline thereafter. The highest male-to-female ratio was seen in Hispanics (20.5) and the lowest in Blacks (7.0) compared with 10.8 in Whites. By contrast, the male-to-female incidence rate ratios were low and fairly stable throughout the different age groups in ESCC.

CONCLUSION

The male-to-female incidence rate ratios in esophageal cancer vary considerably according to histology, age, and race. The highest sex ratios were seen in EA in the age group 50-59, rendering plausibility to the hypothesis that female sex hormone exposure may play a protective role in the development of this cancer.

Hormonal factors and risks of esophageal squamous cell carcinoma and adenocarcinoma in postmenopausal women

The incidences of esophageal adenocarcinoma and squamous cell carcinoma (SCC) are higher in males than in females. We investigated whether female-related hormonal factors are associated with risks of these two types of esophageal cancer. We examined the association between use of hormone therapy (HT) and the risks of esophageal adenocarcinoma and SCC in postmenopausal women enrolled in the Women's Health Initiative (WHI) clinical trials and observational studies. Twenty-three esophageal adenocarcinoma and 34 esophageal SCC cases were confirmed among the 161,080 participants, after a median of 11.82 years of follow-up. Risk of esophageal SCC was lower among HT users (past users: HR = 0.25, 95% CI: 0.06-1.10 in 2 cases; current users: HR = 0.41, 95% CI: 0.18-0.94 in 9 cases). A decreased esophageal SCC risk was observed for current users of estrogen plus progestin (E+P) therapy (HR = 0.25, 95% CI: 0.07-0.86 in 3 cases) but not for current users of estrogen-only therapy (HR = 0.96, 95% CI: 0.28-3.29 in 6 cases). No association was observed between the use of HT and the risk of esophageal adenocarcinoma. No other reproductive or hormonal factors were significantly associated with the risk of either SCC or adenocarcinoma. Current use of E+P therapy was found to be associated with a decreased risk of esophageal SCC, but no association was observed with esophageal adenocarcinoma. To provide more definitive evidence, a pooled analysis of all available studies or a much larger study would be needed.

Hormonal factors and risks of esophageal squamous cell carcinoma and adenocarcinoma in postmenopausal women

The incidences of esophageal adenocarcinoma and squamous cell carcinoma (SCC) are higher in males than in females. We investigated whether female-related hormonal factors are associated with risks of these two types of esophageal cancer. We examined the association between use of hormone therapy (HT) and the risks of esophageal adenocarcinoma and SCC in postmenopausal women enrolled in the Women's Health Initiative (WHI) clinical trials and observational studies. Twenty-three esophageal adenocarcinoma and 34 esophageal SCC cases were confirmed among the 161,080 participants, after a median of 11.82 years of follow-up. Risk of esophageal SCC was lower among HT users (past users: HR = 0.25, 95% CI: 0.06-1.10 in 2 cases; current users: HR = 0.41, 95% CI: 0.18-0.94 in 9 cases). A decreased esophageal SCC risk was observed for current users of estrogen plus progestin (E+P) therapy (HR = 0.25, 95% CI: 0.07-0.86 in 3 cases) but not for current users of estrogen-only therapy (HR = 0.96, 95% CI: 0.28-3.29 in 6 cases). No association was observed between the use of HT and the risk of esophageal adenocarcinoma. No other reproductive or hormonal factors were significantly associated with the risk of either SCC or adenocarcinoma. Current use of E+P therapy was found to be associated with a decreased risk of esophageal SCC, but no association was observed with esophageal adenocarcinoma. To provide more definitive evidence, a pooled analysis of all available studies or a much larger study would be needed.

Menstrual and reproductive factors, exogenous hormone use, and gastric cancer risk in a cohort of women from the European Prospective Investigation Into Cancer and Nutrition

The worldwide incidence of gastric adenocarcinoma (GC) is lower in women than in men. Furthermore, cancer patients treated with estrogens have been reported to have a lower subsequent risk of GC. The authors conducted a prospective analysis of menstrual and reproductive factors, exogenous hormone use, and GC in 335,216 women from the European Prospective Investigation Into Cancer and Nutrition, a cohort study of individuals aged 35-70 years from 10 European countries. After a mean follow-up of 8.7 years (through 2004), 181 women for whom complete exposure data were available developed GC. Adjusted hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards models. All statistical tests were 2-sided. Women who had ovariectomy had a 79% increased risk of GC (based on 25 cases) compared with women who did not (hazard ratio = 1.79, 95% confidence interval: 1.15, 2.78). Total cumulative years of menstrual cycling was inversely associated with GC risk (fifth vs. first quintile: hazard ratio = 0.55, 95% confidence interval: 0.31, 0.98; P(trend) = 0.06). No other reproductive factors analyzed were associated with risk of GC. The results of this analysis provide some support for the hypothesis that endogenous ovarian sex hormones lower GC incidence in women.

Male predominance of upper gastrointestinal adenocarcinoma cannot be explained by differences in tobacco smoking in men versus women

BACKGROUND

Adenocarcinomas of the upper gastrointestinal tract (UGI) show remarkable male predominance. As smoking is a well-established risk factor, we investigated the role of tobacco smoking in the male predominance of UGI adenocarcinomas in the United States NIH-AARP Diet and Health Study.

METHOD

A questionnaire was completed by 281,422 men and 186,133 women in 1995-1996 who were followed until 31st December 2003. Incident UGI adenocarcinomas were identified by linkage to state cancer registries. We present age-standardised cancer incidence rates per 100,000-person years and male/female ratios (M/F) calculated from age-adjusted Cox proportional hazards models, both with 95% confidence intervals (CI).

RESULTS

After 2013,142-person years follow-up, 338 adenocarcinomas of the oesophagus, 261 of gastric cardia and 222 of gastric non-cardia occurred in men. In women, 23 tumours of oesophagus, 36 of gastric cardia and 88 of gastric non-cardia occurred in 1351,958-person years follow-up. The age-standardised incidence rate of all adenocarcinoma sites was 40.5 (37.8-43.3) and 11.0 (9.2-12.8) in men and women, respectively. Among smokers, the M/F of all UGI adenocarcinomas was 3.4 (2.7-4.1), with a M/F of 7.3 (4.6-11.7) for tumours in oesophagus, 3.7 (2.5-5.4) for gastric cardia and 1.7 (1.2-2.3) for gastric non-cardia. In non-smokers, M/F ratios were 14.2 (5.1-39.5) for oesophagus, 6.1 (2.6-14.7) for gastric cardia and 1.3 (0.8-2.0) for gastric non-cardia. The overall M/F ratio was 3.0 (2.2-4.3).

CONCLUSION

The male predominance was similar in smokers and non-smokers for these cancer sites. These results suggest that the male predominance of upper GI adenocarcinomas cannot be explained by differences in smoking histories.