Conjugated equine estrogens and colorectal cancer incidence and survival: the Women's Health Initiative randomized clinical trial

Sex steroid metabolism and action in colon health and disease

The colon is the largest hormonally active tissue in the human body. It has been known for over a hundred years that various hormones and bioactive peptides play important roles in colon function. More recently there is a growing interest in the role the sex steroids, oestrogens and androgens, may play in both normal colon physiology and colon pathophysiology. In this review, we examine the potential role oestrogens and androgens play in the colon. The metabolism and subsequent action of sex steroids in colonic tissue is discussed and how these hormones impact colon motility is investigated. Furthermore, we also determine how oestrogens and androgens influence colorectal cancer incidence and development and highlight potential new therapeutic targets for this malignancy. This review also examines how sex steroids potentially impact the severity and progression of other colon disease, such as diverticulitis, irritable bowel syndrome, and polyp formation.

Changing Colorectal Cancer Trends in Asians: Epidemiology and Risk Factors

Once an infrequent disease in parts of Asia, the rate of colorectal cancer in recent decades appears to be steadily increasing. Colorectal cancer represents one of the most important causes of cancer mortality worldwide, including in many regions in Asia. Rapid changes in socioeconomic and lifestyle habits have been attributed to the notable increase in the incidence of colorectal cancers in many Asian countries. Through published data from the International Agency for Cancer Research (IARC), we utilized available continuous data to determine which Asian nations had a rise in colorectal cancer rates. We found that East and South East Asian countries had a significant rise in colorectal cancer rates. Subsequently, we summarized here the known genetics and environmental risk factors for colorectal cancer among populations in this region as well as approaches to screening and early detection that have been considered across various countries in the region.

Colorectal Cancer Chemoprevention: A Dream Coming True?

Colorectal cancer (CRC) is one of the deadliest forms of cancer worldwide. CRC development occurs mainly through the adenoma-carcinoma sequence, which can last decades, giving the opportunity for primary prevention and early detection. CRC prevention involves different approaches, ranging from fecal occult blood testing and colonoscopy screening to chemoprevention. In this review, we discuss the main findings gathered in the field of CRC chemoprevention, focusing on different target populations and on various precancerous lesions that can be used as efficacy evaluation endpoints for chemoprevention. The ideal chemopreventive agent should be well tolerated and easy to administer, with low side effects. Moreover, it should be readily available at a low cost. These properties are crucial because these compounds are meant to be used for a long time in populations with different CRC risk profiles. Several agents have been investigated so far, some of which are currently used in clinical practice. However, further investigation is needed to devise a comprehensive and effective chemoprevention strategy for CRC.

Hormone Therapy for the Primary Prevention of Chronic Conditions in Postmenopausal Persons: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

It is uncertain whether hormone therapy should be used for the primary prevention of chronic conditions such as heart disease, osteoporosis, or some types of cancers.

OBJECTIVE

To update evidence for the US Preventive Services Task Force on the benefits and harms of hormone therapy in reducing risks for chronic conditions.

DATA SOURCES

PubMed/MEDLINE, Cochrane Library, EMBASE, and trial registries from January 1, 2016, through October 12, 2021; surveillance through July 2022.

STUDY SELECTION

English-language randomized clinical trials and prospective cohort studies of fair or good quality.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; meta-analyses when at least 3 similar studies were available.

MAIN OUTCOMES AND MEASURES

Morbidity and mortality related to chronic conditions; health-related quality of life.

RESULTS

Twenty trials (N = 39 145) and 3 cohort studies (N = 1 155 410) were included. Participants using estrogen only compared with placebo had significantly lower risks for diabetes over 7.1 years (1050 vs 903 cases; 134 fewer [95% CI, 18-237]) and fractures over 7.2 years (1024 vs 1413 cases; 388 fewer [95% CI, 277-489]) per 10 000 persons. Risks per 10 000 persons were statistically significantly increased for gallbladder disease over 7.1 years (1113 vs 737 cases; 377 more [95% CI, 234-540]), stroke over 7.2 years (318 vs 239 cases; 79 more [95% CI, 15-159]), venous thromboembolism over 7.2 years (258 vs 181 cases; 77 more [95% CI, 19-153]), and urinary incontinence over 1 year (2331 vs 1446 cases; 885 more [95% CI, 659-1135]). Participants using estrogen plus progestin compared with placebo experienced significantly lower risks, per 10 000 persons, for colorectal cancer over 5.6 years (59 vs 93 cases; 34 fewer [95% CI, 9-51]), diabetes over 5.6 years (403 vs 482 cases; 78 fewer [95% CI, 15-133]), and fractures over 5 years (864 vs 1094 cases; 230 fewer [95% CI, 66-372]). Risks, per 10 000 persons, were significantly increased for invasive breast cancer (242 vs 191 cases; 51 more [95% CI, 6-106]), gallbladder disease (723 vs 463 cases; 260 more [95% CI, 169-364]), stroke (187 vs 135 cases; 52 more [95% CI, 12-104]), and venous thromboembolism (246 vs 126 cases; 120 more [95% CI, 68-185]) over 5.6 years; probable dementia (179 vs 91 cases; 88 more [95% CI, 15-212]) over 4.0 years; and urinary incontinence (1707 vs 1145 cases; 562 more [95% CI, 412-726]) over 1 year.

CONCLUSIONS AND RELEVANCE

Use of hormone therapy in postmenopausal persons for the primary prevention of chronic conditions was associated with some benefits but also with an increased risk of harms.

An analysis of sexual dimorphism in the tumor microenvironment of colorectal cancer

Women with colorectal cancer (CRC) have survival advantages over men, yet the underlying mechanisms are unclear. T cell infiltration within the CRC tumor microenvironment (TME) correlates strongly with survival. We hypothesized that women with CRC have increased T cell infiltration and differential gene expression in the TME compared to men. Tissue microarrays comprising primary tumor, tumor infiltrated lymph nodes, and uninvolved colon were created from CRC patients. Proportions of CD4 positive (CD4+) and CD8 positive (CD8+) T cells were identified using immunohistochemistry. TME immune- and cancer-related genetic expression from primary and metastatic CRC tumor were also evaluated via the NanoStringIO360 panel and The Cancer Genome Atlas Project database. CD4+ was higher in tumor samples from women compared to men (22.04% vs. 10.26%, p=0.002) and also in lymph node samples (39.54% vs. 8.56%, p=0.001). CD8+ was increased in uninvolved colon from women compared to men (59.40% vs. 43.61%, p=0.015), and in stage I/II tumors compared to III/IV in all patients (37.01% vs. 23.91%, p=0.009). Top CD8+ tertile patients survived longer compared to the bottom (43.9 months vs. 25.3 months, p=0.007). Differential gene expression was observed in pathways related to Treg function, T cell activity, and T cell exhaustion, amongst several others, in women compared to men. Thus, significant sexual dimorphism exists in the TME that could contribute to survival advantages observed in female patients with CRC.

The Prediction of Peritoneal Carcinomatosis in Patients with Colorectal Cancer Using Machine Learning

The incidence of colon, rectal, and colorectal cancer is very high, and diagnosis is often made in the advanced stages of the disease. In cases where peritoneal carcinomatosis is limited, patients can benefit from newer treatment options if the disease is promptly identified, and they are referred to specialized centers. Therefore, an essential diagnostic benefit would be identifying those factors that could lead to early diagnosis. A retrospective study was performed using patient data gathered from 2010 to 2020. The collected data were represented by routine blood tests subjected to stringent inclusion and exclusion criteria. In order to determine the presence or absence of peritoneal carcinomatosis in colorectal cancer patients, three types of machine learning approaches were applied: a neuro-evolutive methodology based on artificial neural network (ANN), support vector machines (SVM), and random forests (RF), all combined with differential evolution (DE). The optimizer (DE in our case) determined the internal and structural parameters that defined the ANN, SVM, and RF in their optimal form. The RF strategy obtained the best accuracy in the testing phase (0.75). Using this RF model, a sensitivity analysis was applied to determine the influence of each parameter on the presence or absence of peritoneal carcinomatosis.

Predictors of CRC Stage at Diagnosis among Male and Female Adults Participating in a Prospective Cohort Study: Findings from Alberta's Tomorrow Project

Colorectal cancer (CRC) is a leading cause of morbidity and mortality in Canada. CRC screening and other factors associated with early-stage disease can improve CRC treatment efficacy and survival. This study examined factors associated with CRC stage at diagnosis among male and female adults using data from a large prospective cohort study in Alberta, Canada. Baseline data were obtained from healthy adults aged 35–69 years participating in Alberta’s Tomorrow Project. Factors associated with CRC stage at diagnosis were evaluated using Partial Proportional Odds models. Analyses were stratified to examine sex-specific associations. A total of 267 participants (128 males and 139 females) developed CRC over the study period. Among participants, 43.0% of males and 43.2% of females were diagnosed with late-stage CRC. Social support, having children, and caffeine intake were predictors of CRC stage at diagnosis among males, while family history of CRC, pregnancy, hysterectomy, menopausal hormone therapy, lifetime number of Pap tests, and household physical activity were predictive of CRC stage at diagnosis among females. These findings highlight the importance of sex differences in susceptibility to advanced CRC diagnosis and can help inform targets for cancer prevention programs to effectively reduce advanced CRC and thus improve survival.

The effect of menopausal hormone therapy on gastrointestinal cancer risk and mortality in South Korea: a population-based cohort study

Background

The effect of menopausal hormone therapy (MHT) on gastrointestinal (GI) cancers is controversial, and no research has been conducted in the East. This study investigates the association between MHT and GI cancer risks in South Korea.

Methods

A prescription-based cohort study was conducted using the NHIS Sample Cohort (2002–2013) of Korea. We used 1:5 propensity score matching, and 22,577 MHT users and 111,113 non-users were selected. Kaplan–Meier survival curves with log-rank tests were used. Cox proportional hazard models were used to estimate hazard ratios (HR) with 95% confidence intervals (CI). Landmark analysis was used to determine dose–response relationship.

Results

The median follow-up was 79.6 of months. Kaplan–Meier survival curve showed less frequent GI cancer diagnoses in MHT users compared to non-users (0.13 vs. 0.16 per 100,000 person-years). Menopausal hormone therapy was associated with decreased incidence of GI cancer (HR = 0.809, 95%CI = 0.691–0.946) and colorectal cancer (CRC) (HR = 0.757, 95%CI = 0.577–0.995). Gastric cancer (GC) incidence showed marginal significance (HR = 0.787, 95%CI = 0.605–1.023). The mortality from GI cancer was lower in MHT users than in non-users (HR = 0.737, 95%CI = 0.547–0.993). The relationship between MHT and GI cancer was stronger with increasing MHT dose in terms of both incidence (P_trend = 0.0002) and mortality (P_trend = 0.0064).

Conclusions

The association between MHT use and reduced risks of GI cancers was attributed to CRC and GC and showed a dose–response relationship in a population-based cohort study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02021-y.

Impact of menopausal hormone therapy on colorectal cancer risk-A systematic review

Colorectal cancer (CRC) is the second most frequently diagnosed cancer in females worldwide. Menopausal hormone therapy (MHT) has been proposed as a potential protective factor for the development of CRC. Yet, the available evidence is controversial. Thus, we aimed at summarizing the current evidence on the effect of MHT on CRC through a systematic review. A systematic literature search identified 1001 potentially relevant articles, out of which 57 original studies and nine meta-analyses were deemed eligible for the final synthesis. The evidence synthesis showed the following: (1) MHT showed a heterogeneity in findings for CRC risk with a slight tendency to a neutral or protective effect; (2) MHT effect was either neutral or protective on colorectal adenoma; (3) MHT had no impact on tumour grade, subsite and histologic types; (4) MHT was not associated with CRC mortality; and (5) MHT showed heterogeneous effects on CRC stage and invasiveness, respectively. In summary, despite some evidence pointing towards a protective effect of MHT on CRC, MHT is currently not recommended for primary CRC prevention by international guidelines due to several important, potentially harmful effects.

Occlusive stenosis - atypical presentation of right colon cancer

Colorectal cancers are one of the most frequent malignancies worldwide. Significant differences are described in relation to the location of tumors within the colon. Thus, between right and left colon cancer there are epidemiological, clinical, genetic, evolutionary and prognostic differences. Considering these premises, right and left colon cancers can be seen as distinct pathological entities. In right colon cancer the initial phases are often asymptomatic and the presence of symptoms is in relation to advanced phases and complications. We report the case of a 64-year-old man with no significant medical history who was admitted and operated as an emergency for stenotic and perforated tumor of the right colon. Operative exploration revealed distended small bowel loops and caecum up to the ascending colon where a stenosing tumor is found. The tumor extends to a small bowel loop and also exhibit a perforation. Right hemicolectomy was performed, with favorable postoperative evolution and discharge on 7th day.

Poorer prognosis in young female patients with non-metastatic colorectal cancer: a hospital-based analysis of 5,047 patients in China

Purpose

To investigate the association of age and sex on survival in non-metastatic colorectal cancer (CRC) patients and to identify groups at high risk for poor outcomes.

Materials and methods

We performed a retrospective analysis of 5,047 non-metastatic CRC patients from 2008 to 2013. Data regarding age at diagnosis; gender; tumor site; tumor stage; differentiation; lymphatic, neural or vascular invasion; and survival outcomes were collected. Patients were stratified into 10-year age groups (≤35, 36-45, 46-55, 56-65, 66-75, >75) and then further analyzed in three age groups (≤35, 36-75, >75). Disease-free survival (DFS) and overall survival (OS) were evaluated using univariate and multivariate Cox regression models.

Results

Of the 5,047 eligible patients, 41.3% were female. The tumor stages were balanced between the genders. In the female patients, the tumor stages were similarly distributed among the different age groups, while younger male patients were diagnosed with more advanced disease (P<0.001 for trend). When stratified into three age groups, young females experienced significantly poorer survival than young males (DFS: hazard ratio [HR]=1.85 [1.04-3.30], OS: HR=2.65 [1.11-6.34]). After adjusting for tumor stage, site, differentiated grade and lymphatic or vascular invasion status, females ≤35 and >75 had shorter DFS than patients between 36 and 75 years old (HR=1.57 [1.03-2.38] and HR=1.51 [1.11-2.05, respectively]), while there was no difference in DFS between females ≤35 and those >75. For male patients, older age was associated with poorer OS after the same adjustment.

Conclusion

Young female CRC patients (≤35 years old) had the poorest DFS and quite poor OS compared to the other age groups. This emphasizes the need for health care providers to have a heightened awareness and to conduct further research when caring for young female CRC patients.

Hormone Replacement Therapy and Colorectal Cancer Incidence and Mortality in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

INTRODUCTION

Hormone replacement therapy has been shown to reduce colorectal cancer incidence, but its effect on colorectal cancer mortality is controversial. The objective of this study was to determine the effect of hormone replacement therapy on survival from colorectal cancer.

PATIENTS AND METHODS

We performed a secondary analysis of data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, a large multicenter randomized trial run from 1993 to 2001, with follow-up data recently becoming mature. Participants were women aged 55 to 74 years, without recent colonoscopy. Data from the trial were analyzed to evaluate colorectal cancer incidence, disease-specific mortality, and all-cause mortality based on subjects' use of hormone replacement therapy at the time of randomization: never, current, or former users.

RESULTS

A total of 75,587 women with 912 (1.21%) incident colorectal cancers and 239 associated deaths were analyzed, with median follow-up of 11.9 years. Overall, 88.6% were non-Hispanic white, and < 10% had not completed high school. The never-user group was slightly older than the current or former user groups (average, 63.8 vs. 61.4 vs. 63.3 years; P < .001). Almost one-half (47.1%) of the current users had undergone hysterectomy, compared with 21.6% of never-users and 34.0% of former users (P < .001). Adjusted colorectal cancer incidence in current users compared to never-users was lower (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69-0.94; P = .005), as was death from colorectal cancer (HR, 0.63; 95% CI, 0.47-0.85; P = .002) and all-cause mortality (HR, 0.76; 95% CI, 0.72-0.80; P < .001).

CONCLUSIONS

Hormone replacement therapy is associated with a reduced risk of colorectal cancer incidence and improved colorectal cancer-specific survival, as well as all-cause mortality.

Sex-Specific Differences in Colon Cancer when Quality Measures Are Adhered to: Results from International, Prospective, Multicenter Clinical Trials

BACKGROUND

There is no consensus on the relationship between patient sex and the location, stage, and oncologic outcome of colon cancer (CC). We hypothesized that there is a sex-specific difference in the biology and management of CC.

STUDY DESIGN

Our cohort was drawn from a database of patients enrolled in international trials of nodal ultrastaging for nonmetastatic CC. These trials required strict adherence to surgical and pathologic quality measures. Postoperative follow-up included colonoscopy at 1 and 4 years and annual CT scans. Sex-specific differences in tumor biology, location, stage, and recurrence were evaluated by chi-square, Fischer's exact, and independent t-tests.

RESULTS

The cohort included 435 males (median age 69 years) and 423 females (median age 70 years). Females had more right-sided (p = 0.03) and earlier T stage (p = 0.05) tumors, but there was no sex-based difference in pathologic grade, total lymph nodes retrieved, nodal positivity (p = 0.47) or lymphovascular invasion (p = 0.45). The overall 4-year disease-free survival (DFS) was comparable in females and males (77.9% and 77.5%, respectively). By multivariate analysis, only nodal positivity and cancer recurrence affected overall survival (OS) (p = 0.008). Neither sex nor primary tumor affected DFS or OS.

CONCLUSIONS

This is the first prospective study to demonstrate sex-specific differences in location and T stage of CC when surgical and pathologic management adhered to strict quality standards. The predominance of right-sided CC in females suggests that flexible sigmoidoscopy may be inadequate for screening and surveillance. Interestingly, earlier stage and right-sided location did not confer a DFS or OS advantage for women. Additional studies are needed to determine why females have a higher propensity for right-sided lesions and a potential difference in CC biology.

Long-term hormone therapy for perimenopausal and postmenopausal women

BACKGROUND: Hormone therapy (HT) is widely provided for control of menopausal symptoms and has been used for the management and prevention of cardiovascular disease, osteoporosis and dementia in older women. This is an updated version of a Cochrane review first published in 2005. OBJECTIVES: To assess effects of long-term HT (at least 1 year's duration) on mortality, cardiovascular outcomes, cancer, gallbladder disease, fracture and cognition in perimenopausal and postmenopausal women during and after cessation of treatment. SEARCH METHODS: We searched the following databases to September 2016: Cochrane Gynaecology and Fertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and PsycINFO. We searched the registers of ongoing trials and reference lists provided in previous studies and systematic reviews. SELECTION CRITERIA: We included randomised double-blinded studies of HT versus placebo, taken for at least 1 year by perimenopausal or postmenopausal women. HT included oestrogens, with or without progestogens, via the oral, transdermal, subcutaneous or intranasal route. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risk of bias and extracted data. We calculated risk ratios (RRs) for dichotomous data and mean differences (MDs) for continuous data, along with 95% confidence intervals (CIs). We assessed the quality of the evidence by using GRADE methods. MAIN RESULTS: We included 22 studies involving 43,637 women. We derived nearly 70% of the data from two well-conducted studies (HERS 1998; WHI 1998). Most participants were postmenopausal American women with at least some degree of comorbidity, and mean participant age in most studies was over 60 years. None of the studies focused on perimenopausal women.In relatively healthy postmenopausal women (i.e. generally fit, without overt disease), combined continuous HT increased the risk of a coronary event (after 1 year's use: from 2 per 1000 to between 3 and 7 per 1000), venous thromboembolism (after 1 year's use: from 2 per 1000 to between 4 and 11 per 1000), stroke (after 3 years' use: from 6 per 1000 to between 6 and 12 per 1000), breast cancer (after 5.6 years' use: from 19 per 1000 to between 20 and 30 per 1000), gallbladder disease (after 5.6 years' use: from 27 per 1000 to between 38 and 60 per 1000) and death from lung cancer (after 5.6 years' use plus 2.4 years' additional follow-up: from 5 per 1000 to between 6 and 13 per 1000).Oestrogen-only HT increased the risk of venous thromboembolism (after 1 to 2 years' use: from 2 per 1000 to 2 to 10 per 1000; after 7 years' use: from 16 per 1000 to 16 to 28 per 1000), stroke (after 7 years' use: from 24 per 1000 to between 25 and 40 per 1000) and gallbladder disease (after 7 years' use: from 27 per 1000 to between 38 and 60 per 1000) but reduced the risk of breast cancer (after 7 years' use: from 25 per 1000 to between 15 and 25 per 1000) and clinical fracture (after 7 years' use: from 141 per 1000 to between 92 and 113 per 1000) and did not increase the risk of coronary events at any follow-up time.Women over 65 years of age who were relatively healthy and taking continuous combined HT showed an increase in the incidence of dementia (after 4 years' use: from 9 per 1000 to 11 to 30 per 1000). Among women with cardiovascular disease, use of combined continuous HT significantly increased the risk of venous thromboembolism (at 1 year's use: from 3 per 1000 to between 3 and 29 per 1000). Women taking HT had a significantly decreased incidence of fracture with long-term use.Risk of fracture was the only outcome for which strong evidence showed clinical benefit derived from HT (after 5.6 years' use of combined HT: from 111 per 1000 to between 79 and 96 per 1000; after 7.1 years' use of oestrogen-only HT: from 141 per 1000 to between 92 and 113 per 1000). Researchers found no strong evidence that HT has a clinically meaningful impact on the incidence of colorectal cancer.One trial analysed subgroups of 2839 relatively healthy women 50 to 59 years of age who were taking combined continuous HT and 1637 who were taking oestrogen-only HT versus similar-sized placebo groups. The only significantly increased risk reported was for venous thromboembolism in women taking combined continuous HT: Their absolute risk remained low, at less than 1/500. However, other differences in risk cannot be excluded, as this study was not designed to have the power to detect differences between groups of women within 10 years of menopause.For most studies, risk of bias was low in most domains. The overall quality of evidence for the main comparisons was moderate. The main limitation in the quality of evidence was that only about 30% of women were 50 to 59 years old at baseline, which is the age at which women are most likely to consider HT for vasomotor symptoms. AUTHORS' CONCLUSIONS: Women with intolerable menopausal symptoms may wish to weigh the benefits of symptom relief against the small absolute risk of harm arising from short-term use of low-dose HT, provided they do not have specific contraindications. HT may be unsuitable for some women, including those at increased risk of cardiovascular disease, increased risk of thromboembolic disease (such as those with obesity or a history of venous thrombosis) or increased risk of some types of cancer (such as breast cancer, in women with a uterus). The risk of endometrial cancer among women with a uterus taking oestrogen-only HT is well documented.HT is not indicated for primary or secondary prevention of cardiovascular disease or dementia, nor for prevention of deterioration of cognitive function in postmenopausal women. Although HT is considered effective for the prevention of postmenopausal osteoporosis, it is generally recommended as an option only for women at significant risk for whom non-oestrogen therapies are unsuitable. Data are insufficient for assessment of the risk of long-term HT use in perimenopausal women and in postmenopausal women younger than 50 years of age.

The Effect of Sex on the Azoxymethane/Dextran Sulfate Sodium-treated Mice Model of Colon Cancer

Background

The colitis-associated cancer exhibits different characteristics according to sex in the initiation and progression of the tumors. The aim of this study was to investigate the sex-associated difference in the azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated cancer model.

Methods

The AOM/DSS ICR mouse model was established to compare male with female, and then the severity of colitis-associated carcinogenesis was examined macroscopically and histologically regarding the number, size, and location of tumors. Subsequently, levels of colonic mucosal cytokine, interleukin (IL)-1β and myeloperoxidase (MPO) were assessed.

Results

At the 16th week, the tumor multiplicity and the pro-inflammatory factors differed according to sex. The total tumor number was significantly higher in male (P = 0.020) and the number of large tumors (diameter > 2 mm) was higher in male (P = 0.026). In male, the tumors located more in distal colon (P = 0.001). MPO was significantly higher in AOM/DSS-treated male mice compared to the control group (P = 0.003), whereas the corresponding female group showed no significant change (P = 0.086). Colonic IL-1β level significantly increased in AOM/DSS groups compared to control groups both in male and female (male, P = 0.014; female, P = 0.005). It was higher in male group; however, there was no statistical significance (P = 0.226).

Conclusions

In AOM/DSS murine model, colitis-associated colon tumorigenesis are induced more severely in male mice than female probably by way of inflammatory mediators such as IL-1β and MPO. The sex-related differences at the animal model of colon cancer suggest the importance of approach to disease with sex-specific medicine in human.

Menopausal Hormone Therapy, Age, and Chronic Diseases: Perspectives on Statistical Trends

The release of the Women's Health Initiative (WHI) study in 2002 was a shock to the medical community. Hormone therapy (HT) had generally been considered to be highly beneficial for postmenopausal women since it was the gold standard for relief of menopausal symptoms (hot flashes, night sweats, vaginal atrophy) and it was thought to protect women from osteoporosis, heart disease, and cognitive decline and to generally improve quality of life. However, WHI showed a statistically significant increase in a number of disease states, including breast cancer, cardiovascular disease, and stroke. One problem with the WHI study was that the average age of women in the study was 63, which is considerably older than the age at which most women enter menopause (about 51). The timing hypothesis attempts to rationalize the effect of age on response to HT and risk of various diseases. The data suggests that younger women (50-60) may be protected from heart disease with only a slight increase in breast cancer risk. In contrast, older women (>65) are more susceptible to breast cancer and heart disease and should avoid HT. This Perspective on Statistical Trends evaluates the current data on HT and risk for chronic diseases as a function of age.

How significant is the association between metabolic syndrome and prevalence of colorectal neoplasia?

The incidence and prevalence of metabolic syndrome (MS) and colorectal cancer (CRC) has been rising in developed countries. The association between these two diseases has been widely studied and reported. Less evidence is available about the relationship between MS and CRC precancerous lesions (adenomatous polyps, adenomas). The aim of this paper is to present an overview of our scientific understanding of that topic and its implication in clinical practice. One of the principal goals of current CRC secondary prevention efforts is to detect and remove the precancerous lesions in individuals with an average CRC risk to prevent the development of invasive cancer. MS is not currently considered a high-risk CRC factor and is therefore not included in the guidelines of organized screening programs. However, in light of growing scientific evidence, the approach to patients with MS should be changed. Metabolic risk factors for the development of adenomas and cancers are the same - obesity, impaired glucose tolerance, dyslipidemia, hypertension, cardiovascular diseases and diabetes mellitus type 2. Therefore, the key issue in the near future is the development of a simple scoring system, easy to use in clinical practice, which would identify individuals with high metabolic risk of colorectal neoplasia and would be used for individual CRC secondary prevention strategies. Currently, such scoring systems have been published based on Asian (Asia-Pacific Colorectal Screening Score; APCS) and Polish populations.

Menopausal hormone therapy in cancer survivors: A narrative review of the literature

Decision making regarding the use of menopausal hormone therapy (MHT) for the treatment of bothersome menopausal symptoms in a cancer survivor can be complex, and includes assessment of its impact on disease-free or overall survival. Estrogen receptors are present in several cancer types, but this does not always result in estrogen-mediated tumor proliferation and adverse cancer-related outcomes. Estrogen may even be protective against certain cancers. Menopausal hormone therapy is associated with an increased risk of recurrence and mortality after diagnosis of some cancer types, but not others. We provide a narrative review of the medical literature regarding the risk of cancer recurrence and associated mortality with initiation of MHT after the diagnosis of breast, gynecologic, lung, colorectal, hematologic cancers, and melanoma. Menopausal hormone therapy may be considered for management of bothersome menopausal symptoms in women with some cancer types (e.g., colorectal and hematologic cancer, localized melanoma, and most cervical, vulvar and vaginal cancers), while nonhormonal treatment options may be preferred for others (e.g., breast cancer). In women with other cancer types, recommendations are less straightforward, and the use of MHT must be individualized.

Diet Quality and Colorectal Cancer Risk in the Women's Health Initiative Observational Study

Diet quality index scores on Healthy Eating Index 2010 (HEI-2010), Alternative HEI-2010, alternative Mediterranean Diet Index, and the Dietary Approaches to Stop Hypertension (DASH) index have been inversely associated with all-cause and cancer-specific death. This study assessed the association between these scores and colorectal cancer (CRC) incidence as well as CRC-specific mortality in the Women's Health Initiative Observational Study (1993-2012), a US study of postmenopausal women. During an average of 12.4 years of follow-up, there were 938 cases of CRC and 238 CRC-specific deaths. We estimated multivariate hazard ratios and 95% confidence intervals for relationships between quintiles of diet scores (from baseline food frequency questionnaires) and outcomes. HEI-2010 score (hazard ratios were 0.81, 0.77, and 0.73 with P values of 0.04, 0.01, and <0.01 for quintiles 3-5 vs. quintile 1, respectively) and DASH score (hazard ratios were 0.72, 0.74, and 0.78 with P values of <0.01, <0.01, and 0.03 for quintiles 3-5 vs. quintile 1, respectively), but not other diet scores, were associated with a lower risk of CRC in adjusted models. No diet scores were significantly associated with CRC-specific mortality. Closer adherence to HEI-2010 and DASH dietary recommendations was inversely associated with risk of CRC in this large cohort of postmenopausal women.

Bisphenol a exposure promotes the migration of NCM460 cells via estrogen receptor-mediated integrin β1/MMP-9 pathway

Bisphenol A (BPA) is a widely used industrial chemical and also an environmental endocrine disruptor (EED), which serves as a monomer in the manufacture of polycarbonate plastics. BPA enters human body mainly through oral intake, and has been reported as being linked to oncogenesis in many tissues. However, the association of BPA intake with gastrointestinal cancer, such as colon cancer, has received less attention. The present study was conducted to investigate the effects of BPA on the migration of normal colon epithelial cells (NCM460 cells) and further elucidate the underlying mechanisms. Our data showed that 1 × 10(-8) M (equivalent to environmental concentration) of BPA potently promoted the migration of NCM460 cells. Interestingly, BPA treatment induced an increase of integrin β1 expression, and the functional blocking of integrin β1 abolished the migration-promoting effects of BPA. Moreover, the results showed that it was estrogen receptor β but not estrogen receptor α that was involved in this migration promotion. In addition, cellular exposure of BPA stimulated the expression and activity of MMP-9, a well-known factor of cell migration. Taken together, these results indicate that environmental concentration of BPA exposure promotes cell migration through activating ERβ-mediated integrin β1/MMP-9 pathway, suggesting exposure to BPA in the colon may present a potential cancer risk. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 799-807, 2016.

Progesterone receptor activation is required for folic acid-induced anti-proliferation in colorectal cancer cell lines

Previously, we demonstrated that folic acid (FA) could inhibit proliferation of colorectal cancer cell lines through activating the folate receptor (FR)α/cSrc/ERK1/2/NFκB/p53 pathway and anti-COLO-205 tumor growth in vivo. Since we recently also demonstrated that female sex hormones could affect the FA's action in regulating endothelial cell proliferation and migration, the aim of this study was to investigate the effect of progesterone (P4) on the FA-induced anti-proliferation in colorectal cancer cells. Treatment with FA significantly reduced the proliferation of the P4 receptor (PR)-positive colon cancer cell lines, COLO-205, HT-29 and LoVo, but did not significantly affect the proliferation of the PR-negative colon cancer cell lines, HCT116 and DLD-1. Pre-treatment with Org 31710, a PR specific antagonist, abolished the FA-induced proliferation inhibition and activation in the signaling pathway involved in regulating proliferation inhibition in these PR positive colorectal cancer cell lines. The involvement of PR in the FA-induced activation of cSrc and up-regulations in cell cycle inhibitory proteins (p21, p27 and p53) was confirmed by knock-down of PR expression using the siRNA technique. Importantly, we show direct protein interaction between FR and PR in COLO-205. Moreover, treatment with FA induced PR activation in COLO-205. Taken together, these data suggest that FA induced proliferation inhibition in colon cancer cells through activation of PR. This finding might explain some of the controversies of FA's effects on cancer growth and provide valuable reference for clinical applications of FA in treating colorectal cancer.

Molecular cancer prevention: Current status and future directions

The heterogeneity and complexity of advanced cancers strongly support the rationale for an enhanced focus on molecular prevention as a priority strategy to reduce the burden of cancer. Molecular prevention encompasses traditional chemopreventive agents as well as vaccinations and therapeutic approaches to cancer-predisposing conditions. Despite challenges to the field, we now have refined insights into cancer etiology and early pathogenesis; successful risk assessment and new risk models; agents with broad preventive efficacy (eg, aspirin) in common chronic diseases, including cancer; and a successful track record of more than 10 agents approved by the US Food and Drug Administration for the treatment of precancerous lesions or cancer risk reduction. The development of molecular preventive agents does not differ significantly from the development of therapies for advanced cancers, yet it has unique challenges and special considerations given that it most often involves healthy or asymptomatic individuals. Agents, biomarkers, cohorts, overall design, and endpoints are key determinants of molecular preventive trials, as with therapeutic trials, although distinctions exist for each within the preventive setting. Progress in the development and evolution of molecular preventive agents has been steadier in some organ systems, such as breast and skin, than in others. In order for molecular prevention to be fully realized as an effective strategy, several challenges to the field must be addressed. Here, the authors provide a brief overview of the context for and special considerations of molecular prevention along with a discussion of the results from major randomized controlled trials.

Reproductive and hormonal factors and mortality among women with colorectal cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Although use of menopausal hormone therapy (MHT) and some reproductive factors have been associated with colorectal cancer (CRC) risk, relations between these factors and survival after CRC diagnosis are unclear.

METHODS

Among 2053 post-menopausal women diagnosed with incident CRC in the NIH-AARP Diet and Health Study, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) using multivariable Cox proportional hazards regression to test associations between oral contraceptive (OC) use, menarche age, age at first birth, parity, menopausal age, and MHT use with all-cause and CRC-specific mortality.

RESULTS

There were 759 deaths (332 CRC-related deaths) over a median follow-up of 7.7 years. We observed no statistically significant associations between OC use, menarche age, age at first birth, parity, menopausal age, and mortality. Compared with never MHT use, former use was not associated with mortality, but we found an inverse association among baseline current users, for both all-cause (HR=0.79, 95% CI 0.66-0.94) and CRC mortality (0.76, 0.59-0.99).

CONCLUSION

Future studies should further focus on the mechanisms by which exogenous oestrogen exposure might affect tumour progression and CRC survival.

Sex- and gender-specific disparities in colorectal cancer risk

Colorectal cancer is one of the most common causes of cancer morbidity both in men and in women. However, females over 65 years old show higher mortality and lower 5-year survival rate of colorectal cancer compared to their age-matched male counterparts. The objective of this review is to suggest gender-based innovations to improve colorectal cancer outcomes in females. Women have a higher risk of developing right-sided (proximal) colon cancer than men, which is associated with more aggressive form of neoplasia compared to left-sided (distal) colon cancer. Despite differences in tumor location between women and men, most of scientific researchers do not consider sex specificity for study design and interpretation. Also, colorectal cancer screening guidelines do not distinguish females from male, which may explain the higher frequency of more advanced neoplasia when tumors are first detected and false negative results in colonoscopy in females. Moreover, socio-cultural barriers within females are present to delay screening and diagnosis. Few studies, among studies that included both men and women, have reported sex-specific estimates of dietary risk factors which are crucial to establish cancer prevention guidelines despite sex- and gender-associated differences in nutrient metabolism and dietary practices. Furthermore, anti-cancer drug use for colorectal cancer treatment can cause toxicity to the reproductive system, and gender-specific recurrence and survival rates are reported. Therefore, by understanding sex- and gender-related biological and socio-cultural differences in colorectal cancer risk, gender-specific strategies for screening, treatment and prevention protocols can be established to reduce the mortality and improve the quality of life.

Sex- and gender-specific disparities in colorectal cancer risk

Colorectal cancer is one of the most common causes of cancer morbidity both in men and in women. However, females over 65 years old show higher mortality and lower 5-year survival rate of colorectal cancer compared to their age-matched male counterparts. The objective of this review is to suggest gender-based innovations to improve colorectal cancer outcomes in females. Women have a higher risk of developing right-sided (proximal) colon cancer than men, which is associated with more aggressive form of neoplasia compared to left-sided (distal) colon cancer. Despite differences in tumor location between women and men, most of scientific researchers do not consider sex specificity for study design and interpretation. Also, colorectal cancer screening guidelines do not distinguish females from male, which may explain the higher frequency of more advanced neoplasia when tumors are first detected and false negative results in colonoscopy in females. Moreover, socio-cultural barriers within females are present to delay screening and diagnosis. Few studies, among studies that included both men and women, have reported sex-specific estimates of dietary risk factors which are crucial to establish cancer prevention guidelines despite sex- and gender-associated differences in nutrient metabolism and dietary practices. Furthermore, anti-cancer drug use for colorectal cancer treatment can cause toxicity to the reproductive system, and gender-specific recurrence and survival rates are reported. Therefore, by understanding sex- and gender-related biological and socio-cultural differences in colorectal cancer risk, gender-specific strategies for screening, treatment and prevention protocols can be established to reduce the mortality and improve the quality of life.

Prevention of colorectal cancer and dietary management

OBJECTIVES

This systematic review focuses on dietary and lifestyle risk factors for colorectal cancer (CRC) prevention and chemoprevention among high-risk populations.

METHODS AND MATERIALS

We searched PubMed for English-language articles about dietary components, lifestyle risk factors, and chemoprevention agents in relation to colorectal cancer and their references published from 1980 through 2013. We reviewed articles jointly for the most clinically important information, emphasizing randomized trials and meta-analyses where available.

RESULTS

There is convincing evidence that intake of garlic, vitamin B6 and magnesium, active living, maintaining a healthy weight and waist, avoiding or reducing red meat, alcohol, and smoking, as well as hormone replacement therapy among women may significantly protect against developing colorectal cancer. There is less consistent evidence for fruit and vegetable intake (fiber and folate), fish and Omega-3 fatty acids, selenium, dairy, calcium and vitamin D. For high-risk populations, aspirin have been shown to protect against the development of colonic adenomas and CRC, while a minimal effective dose remains unclear.

CONCLUSIONS

Colorectal cancer can be prevented in general population through dietary and lifestyle interventions, and aspirin may be a good choice of chemoprevention agent among high risk individuals.

Menopausal hormone therapy and cancer: changing clinical observations of target site specificity

Menopausal hormone therapy with estrogen plus progestin or estrogen alone (for women with prior hysterectomy) is still used by millions of women for climacteric symptom management throughout the world. Until 2002, hormone therapy influence on cancer risk and other chronic diseases was determined through observational study reports. Since then, results from the Women's Health Initiative randomized, placebo-controlled hormone therapy trials have substantially changed concepts regarding estrogen plus progestin and estrogen alone influence on the most common cancers in postmenopausal women. In these trials, estrogen plus progestin significantly increased breast cancer incidence and deaths from breast cancer, significantly increased deaths from lung cancer, significantly decreased endometrial cancer, and did not have a clinically significant influence on colorectal cancer. In contrast, estrogen alone use in women with prior hysterectomy significantly reduced breast cancer incidence and deaths from breast cancer without significant influence on colorectal cancer or lung cancer. These complex results are discussed in the context of known potential mediating mechanisms of action involved in interaction with steroid hormone receptors.

Nonlinear reduction in risk for colorectal cancer by oral contraceptive use: a meta-analysis of epidemiological studies

PURPOSE

Although the relationship between oral contraceptive (OC) use and colorectal cancer (CRC) risk has been studied extensively, the results of epidemiological studies are controversial. Therefore, we carried out a meta-analysis of epidemiological studies to summarize the available evidence and to quantify the potential dose-response relation.

METHODS

We searched PubMed database for studies of OC use and CRC risk that were published until the end of March 2014. Random- and fixed-effects models were applied to estimate summary relative risks (RRs) and 95 % confidence intervals (CIs).

RESULTS

Twelve cohorts and seventeen case-control studies with a total of 15,790 CRC cases were included in the final analysis. The summary RR for the ever versus never category of OC use was 0.82 (95 % CI 0.76-0.88). Similar result was observed when we compared the longest duration of OC use with the shortest duration (RR = 0.86, 95 % CI 0.76-0.96). Furthermore, the results of stratified analysis were comparable to those of overall meta-analysis. In dose-response analysis, significant inverse associations emerged in nonlinear models for the duration of OC use and CRC (P nonlinearity = 0.001). The greatest risk reduction was observed when the duration of OC use was approximately 42 months. There was moderate heterogeneity in the analysis, and no evidence of small-study bias was observed.

CONCLUSIONS

Based on the findings of this meta-analysis, ever use of OC is associated with lower risk of CRC. Additionally, there is a statistically significant nonlinear inverse association between the duration of OC use and CRC risk.

Postmenopausal hormone therapy and the risks of coronary heart disease, breast cancer, and stroke

The principal findings are briefly reviewed from the Women's Health Initiative trials of the most commonly used postmenopausal hormone regimens in the United States-conjugated equine estrogens and these same estrogens plus medroxyprogesterone acetate. A more detailed review is presented for three major clinical outcomes: coronary heart disease (CHD), the primary trial outcome for which a major benefit was hypothesized; invasive breast cancer, the primary safety outcome for which some adverse effect was expected; and stroke which surfaced as an important adverse effect with both regimens, and one that is influential in decisions concerning the continued use of postmenopausal estrogens alone. The review for these outcomes includes an update on interactions of treatment effects with study subject characteristics and exposures and with prerandomization biomarker levels. It also includes a focus on timing issues that are important to the understanding of treatment effects. Specifically, with combined estrogen plus progestin, CHD risk was elevated early with the elevation dissipating after a few years of treatment, whereas breast cancer elevations increased during the treatment period, and climbed to about a threefold increase following 5 years of adherence. Importantly, breast cancer risk elevations appear to be higher among women who initiate treatment at the menopause, or soon thereafter, compared with women having a longer gap time. Stroke effects, on the contrary, did not seem to vary appreciably with these timing issues. The adverse effect was evidently localized to ischemic strokes, for which there was an approximate 50% increase with either regimen. The rather limited knowledge concerning the biomarkers and biological pathways that mediate the hormone therapy effects on these diseases is also briefly reviewed.

Oestrogens promote tumorigenesis in a mouse model for colitis-associated cancer

BACKGROUND

Hormone replacement therapy increases the risk of developing ulcerative colitis in postmenopausal women. Chronic intestinal inflammation predisposes to colon cancer development, but effects of female hormones on colitis-associated cancer development have not been examined.

AIM

To investigate the role of female hormones in the dextran sodium sulfate (DSS)-azoxymethane (AOM) mouse model for colitis-associated cancer.

DESIGN

We performed ovariectomies, or sham operations, on mice, and supplemented these animals with indicated hormones. Additionally, we used oestrogen receptor α or β (Erα or Erβ) mutant mice. To study colitis or colitis-associated cancer, we used DSS only, or DSS and AOM, respectively.

RESULTS

Ovariectomy protects female mice against colitis-associated tumour development. Hormone replacement in ovariectomised mice with either oestradiol (E2), medroxyprogesterone acetate or a combination of both suggests that oestrogens are the ovary-derived factor that promotes tumour development in the context of inflammatory damage. E2-treated animals showed increased clinical symptoms and Il-6 production upon DSS-induced colitis and enhanced epithelial proliferation. Treatment with E2 markedly increased the numbers of polyps in ovariectomised mice and also strongly promoted tumour progression with all E2-treated animals developing at least one invasive adenocarcinoma, whereas, placebo-treated animals developed adenomas only. Using Er mutant mice, we find that the protumorigenic effect of oestrogen depends on both Erα and Erβ.

CONCLUSIONS

Our results suggest that oestrogens promote inflammation-associated cancer development by impairing the mucosal response to inflammatory damage.

Raloxifene and antiestrogenic gonadorelin inhibits intestinal tumorigenesis by modulating immune cells and decreasing stem-like cells

Studies suggest that estrogen plays a contributing role in colorectal cancer. This project examined the preventive effects of raloxifene, a selective estrogen receptor modulator (SERM), and gonadorelin, an antiestrogenic drug, in female Apc(Min/+) mouse intestinal tumorigenesis. Six-week-old Apc(Min/+)mice were fed diet containing 1 ppm raloxifene or control diet. Gonadorelin (150 ng/mouse) was injected subcutaneously into one treatment group. Intestinal tumors were evaluated for tumor multiplicity and size. Mice treated with raloxifene and gonadorelin showed colon tumor inhibition of 80% and 75%, respectively. Both drugs significantly inhibited small intestinal tumor multiplicity and size (75%-65%, P < 0.0001). Raloxifene and gonadorelin showed significant tumor inhibition with 98% and 94% inhibition of polyps >2 mm in size. In mice fed with raloxifene or injected with gonadorelin, tumors showed significantly reduced proliferating cell nuclear antigen expression (58%-65%, P < 0.0001). Raloxifene treatment decreased β-catenin, cyclin D1, laminin 1β, Ccl6, and stem-like cells (Lgr 5, EpCAM, CD44/CD24), as well as suppressed inflammatory genes (COX-2, mPGES-1, 5-LOX,). Gonadorelin showed significant decrease in COX-2, mPGES-1, iNOS, and stem-like cells or increased NK cells and chemokines required for NK cells. Both drugs were effective in suppressing tumor growth albeit with different mechanisms. These observations show that either suppression of estrogen levels or modulation of estrogen receptor dramatically suppresses small intestinal and colonic tumor formation in female Apc(Min/+) mice. These results support the concept of chemoprevention by these agents in reducing endogenous levels of estrogen or modulating ER signaling.

Chemopreventive efficacy of raloxifene, bexarotene, and their combination on the progression of chemically induced colon adenomas to adenocarcinomas in rats

Estrogen receptor (ER)-β signaling is associated positively in colon tumor progression, whereas downregulation or loss of function of retinoid X receptor (RXR)-α occurs in colon tumors. The chemopreventive efficacies of the estrogen antagonist raloxifene and the selective RXR agonist bexarotene were tested individually and in combination, during promotion and progression stages of colon tumorigenesis. Colon tumors were induced in male F344 rats with azoxymethane and at early adenoma stage, groups of rats (36 or 45 per group) were fed diets containing raloxifene (1.5 or 3 ppm), bexarotene (50 or 100 ppm), or their low-dose combinations for 40 weeks. Raloxifene or bexarotene alone significantly suppressed colon adenocarcinoma formation in terms of multiplicities (mean ± SE): control, 3.59 ± 0.25; 1.5 ppm raloxifene, 2.51 ± 0.29 (P < 0.004); 3 ppm raloxifene, 2.14 ± 0.28 (P < 0.0001); 50 ppm bexarotene, 2.25 ± 0.32 (P < 0.001); 100 ppm bexarotene, 2.1 ± 0.27 (P < 0.0001); and 1.5 ppm raloxifene + 50 ppm bexarotene, 1.57 ± 0.21 (P < 0.0001). The low-dose combination caused significant (56%) inhibition of adenocarcinomas as compared with control diet fed rats. Tumors exposed to raloxifene, bexarotene and/or the combination showed significant suppression of proliferating cell nuclear antigen, cyclin D1, and β-catenin with an increased apoptotic cells (3-fold) and p21 expression (3.8-fold) as compared tumors of rats fed control diet. The combination of low doses of raloxifene and bexarotene significantly suppressed the progression of colonic adenomas to adenocarcinomas and may be useful for colon cancer prevention and/or treatment in high-risk individuals.

Conjugated estrogens for the treatment of menopausal symptoms: a review of safety data

INTRODUCTION

Conjugated equine estrogens (CEE) are widely used for the treatment of menopausal symptoms, such as vasomotor symptoms and vulvovaginal atrophy, and for the prevention of bone loss, in postmenopausal women. The safety profile of CEE has been extensively published over the past 20 years.

AREAS COVERED

Data from randomized controlled trials and from observational studies on the effects of CEE on the risk of breast cancer, endometrial cancer or hyperplasia, other cancers, cardiovascular outcomes, and cognitive function are reviewed. When used alone, CEE are not associated with an increased risk of breast cancer and may be associated with reduced mortality. The risk of cardiovascular events with CEE may be reduced in women who are more recently postmenopausal.

EXPERT OPINION

Numerous clinical studies have evaluated the safety of CEE. The data reviewed in this article describe the breast, endometrial, and cardiovascular safety of unopposed CEE. International recommendations describe CEE as the menopausal symptom treatment of choice, particularly in young or recently postmenopausal hysterectomized women.

Increased risk of colon cancer in men in the pre-diabetes phase

BACKGROUND

Historically, studies exploring the association between type 2 diabetes mellitus (DM) and cancer lack accurate definition of date of DM onset, limiting temporal analyses. We examined the temporal relationship between colon cancer risk and DM using an electronic algorithm and clinical, administrative, and laboratory data to pinpoint date of DM onset.

METHODS

Subjects diagnosed with DM (N = 11,236) between January 1, 1995 and December 31, 2009 were identified and matched at a 5∶1 ratio with 54 365 non-diabetic subjects by age, gender, smoking history, residence, and diagnosis reference date. Colon cancer incidence relative to the reference date was used to develop Cox regression models adjusted for matching variables, body mass index, insurance status, and comorbidities. Primary outcomes measures included hazard ratio (HR) and number needed to be exposed for one additional person to be harmed (NNEH).

RESULTS

The adjusted HR for colon cancer in men before DM onset was 1.28 (95% CI 1.04-1.58, P = 0.0223) and the NNEH decreased with time, reaching 263 at DM onset. No such difference was observed in women. After DM onset, DM did not appear to alter colon cancer risk in either gender.

CONCLUSIONS

Colon cancer risk is increased in diabetic men, but not women, before DM onset. DM did not alter colon cancer risk in men or women after clinical onset. In pre-diabetic men, colon cancer risk increased as time to DM onset decreased, suggesting that the effects of the pre-diabetes phase on colon cancer risk in men are cumulative.

Oestrogen and colorectal cancer: mechanisms and controversies

AIM

The role of oestrogen metabolism and action in colorectal cancer (CRC) is controversial. An extensive review of the current literature, encompassing epidemiological evidence, systemic and peripheral oestrogen concentrations, 17β-hydroxysteroid dehydrogenase (17β-HSD) and aromatase in CRC, steroid sulphatase (STS)/oestrone sulphotransferase (EST) and in vitro and in vivo genomic effects was therefore undertaken.

METHODS

A literature search (key words: colorectal cancer, oestrogen, oestrogen receptor, 17β-HSD, STS, organic anion transporter) was performed using Embase, Medline, and Pubmed and papers were evaluated on scientific relevance on an individual basis.

RESULTS

Epidemiological data highlights that premenopausal women, or postmenopausal women taking hormone replacement therapy, are significantly less likely than males to develop CRC. This implies that oestrogen signalling is most likely involved in CRC physiology and aetiology. Little is known about oestrogen metabolism in the colon. However, the expression of 17β-HSD, STS, and EST, enzymes involved in oestrogen metabolism, have shown prognostic significance. Evidence also suggests that protective effects are modulated through oestrogen receptor beta, although which metabolite of oestrogen, oestradiol (E2) or oestrone (E1), is more active remains undefined. To complicate matters, the changes in the peripheral ratios of these enzymes, oestrogens and receptors most likely influences CRC progression.

CONCLUSION

Epidemiological evidence, now supported by in vitro and in vivo studies, strongly associates oestrogen action and metabolism with CRC. Initially protective against CRC, once developed, results suggests that oestrogens increase proliferation. Consequently, hormone-ablation therapy, already successful against breast and prostate cancer, may be effective against CRC.

Common single-nucleotide polymorphisms in the estrogen receptor β promoter are associated with colorectal cancer survival in postmenopausal women

Loss of estrogen receptor β (ERβ) expression in the gut is associated with colorectal cancer (CRC) initiation and progression. Germline single-nucleotide polymorphisms (SNP) in genes for the sex-steroid hormone receptors are not strongly associated with CRC risk; however, these SNPs have not previously been evaluated in relation to survival after diagnosis. We enrolled 729 women, ages 50 to 74, diagnosed with invasive CRC between 1997 and 2002 in 13 counties covered by the Seattle-Puget Sound Surveillance Epidemiology and End Results cancer registry. Participants provided germline DNA. We selected 99 tag-SNPs for the androgen receptor (AR), ERα (ESR1), ERβ (ESR2), and progesterone receptor (PGR) genes. Mortality outcomes were ascertained from the National Death Index. During a median of 6.6 years of follow-up, 244 deaths occurred (161 from CRC). We identified 20 SNPs (12 of ESR2 and 8 of PGR) for replication in 1,729 women diagnosed with incident invasive CRC (555 deaths; 405 from CRC) from three prospective cohort studies that participate in the Genetics and Epidemiology of Colorectal Cancer Consortium. Three correlated SNPs in the promoter of ESR2 (rs2987983, rs3020443, and rs2978381) were statistically significant predictors of CRC-specific and overall survival. Minor alleles of each were associated with improved survival [for rs2987983, CRC-specific HR, 0.77; 95% confidence interval (CI), 0.60-0.99 in the initial study, and HR, 0.79; CI, 0.64-0.98 in replication]. No associations were noted for SNPs of AR, ESR1, or PGR. SNPs in the promoter of ESR2 may be important to pathways related to the association between ERβ and tumor progression and metastasis.

Gender, anthropometric factors and risk of colorectal cancer with particular reference to tumour location and TNM stage: a cohort study

Background

It remains unclear whether the increased risk of colorectal cancer (CRC) associated with obesity differs by gender, distribution of fat, tumour location and clinical (TNM) stage. The primary aim of this study was to examine these associations in 584 incident colorectal cancer cases from a Swedish prospective population-based cohort including 28098 men and women.

Methods

Seven anthropometric factors; height, weight, bodyfat percentage, hip circumference, waist circumference, BMI and waist-hip ratio (WHR) were categorized into quartiles of baseline anthropometric measurements. Relative risks of CRC, total risk as well as risk of different TNM stages, and risk of tumours located to the colon or rectum, were calculated for all cases, women and men, respectively, using multivariate Cox regression models.

Results

Obesity, as defined by all anthropometric variables, was significantly associated with an overall increased risk of CRC in both women and men. While none of the anthropometric measures was significantly associated with risk of tumour (T)-stage 1 and 2 tumours, all anthropometric variables were significantly associated with an increased risk of T-stage 3 and 4, in particular in men. In men, increasing quartiles of weight, hip, waist, BMI and WHR were significantly associated with an increased risk of lymph node positive (N1 and N2) disease, and risk of both non-metastatic (M0) and metastatic (M1) disease. In women, there were no or weak associations between obesity and risk of node-positive disease, but statistically significant associations between increased weight, bodyfat percentage, hip, BMI and M0 disease. Interestingly, there was an increased risk of colon but not rectal cancer in men, and rectal but not colon cancer in women, by increased measures of weight, hip-, waist circumference and bodyfat percentage.

Conclusions

This study is the first to show a relationship between obesity, measured as several different anthropometric factors, and an increased risk of colorectal cancer of more advanced clinical stage, in particular in men. These findings suggest that risk of CRC differs according to the method of characterising obesity, and also according to gender, location, and tumour stage.

Estrogen plus progestin and colorectal cancer incidence and mortality

PURPOSE

During the intervention phase in the Women's Health Initiative (WHI) clinical trial, use of estrogen plus progestin reduced the colorectal cancer diagnosis rate, but the cancers were found at a substantially higher stage. To assess the clinical relevance of the findings, analyses of the influence of combined hormone therapy on colorectal cancer incidence and colorectal cancer mortality were conducted after extended follow-up.

PATIENTS AND METHODS

The WHI study was a randomized, double-blind, placebo-controlled clinical trial involving 16,608 postmenopausal women with an intact uterus who were randomly assigned to daily 0.625 mg conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate (n = 8,506) or matching placebo (n = 8,102). Colorectal cancer diagnosis rates and colorectal cancer mortality were assessed.

RESULTS

After a mean of 5.6 years (standard deviation [SD], 1.03 years) of intervention and 11.6 years (SD, 3.1 years) of total follow-up, fewer colorectal cancers were diagnosed in the combined hormone therapy group compared with the placebo group (diagnoses/year, 0.12% v 0.16%; hazard ratio [HR], 0.72; 95% CI, 0.56 to 0.94; P = .014). Bowel screening examinations were comparable between groups throughout. Cancers in the combined hormone therapy group more commonly had positive lymph nodes (50.5% v 28.6%; P < .001) and were at higher stage (regional or distant, 68.8% v 51.4%; P = .003). Although not statistically significant, there was a higher number of colorectal cancer deaths in the combined hormone therapy group (37 v 27 deaths; 0.04% v 0.03%; HR, 1.29; 95% CI, 0.78 to 2.11; P = .320).

CONCLUSION

The findings, suggestive of diagnostic delay, do not support a clinically meaningful benefit for combined hormone therapy on colorectal cancer.

Long term hormone therapy for perimenopausal and postmenopausal women

BACKGROUND

Hormone therapy (HT) is widely used for controlling menopausal symptoms and has also been used for the management and prevention of cardiovascular disease, osteoporosis and dementia in older women. This is an updated version of a Cochrane review first published in 2005.

OBJECTIVES

To assess the effects of long term HT on mortality, cardiovascular outcomes, cancer, gallbladder disease, fractures, cognition and quality of life in perimenopausal and postmenopausal women, both during HT use and after cessation of HT use.

SEARCH METHODS

We searched the following databases to February 2012: Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO.

SELECTION CRITERIA

We included randomised double-blind studies of HT versus placebo, taken for at least one year by perimenopausal or postmenopausal women. HT included oestrogens, with or without progestogens, via oral, transdermal, subcutaneous or intranasal routes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRS) for dichotomous data and mean differences (MDs) for continuous data, with 95% confidence intervals (CIs). Where findings were statistically significant, we calculated the absolute risk (AR) in the intervention group (the overall risk of an event in women taking HT).

MAIN RESULTS

Twenty-three studies involving 42,830 women were included. Seventy per cent of the data were derived from two studies (WHI 1998 and HERS 1998). Most participants were postmenopausal American women with at least some degree of co-morbidity, and the mean participant age in most studies was over 60 years. None of the studies focused on perimenopausal women. In relatively healthy postmenopausal women (that is generally fit, without overt disease) combined continuous HT significantly increased the risk of a coronary event (after one year's use: AR 4 per 1000, 95% CI 3 to 7), venous thrombo-embolism (after one year's use: AR 7 per 1000, 95% CI 4 to 11), stroke (after three years' use: AR 18 per 1000, 95% CI 14 to 23), breast cancer (after 5.6 years' use: AR 23 per 1000, 95% CI 19 to 29), gallbladder disease (after 5.6 years' use: AR 27 per 1000, 95% CI 21 to 34) and death from lung cancer (after 5.6 years' use plus 2.4 years' additional follow-up: AR 9 per 1000, 95% CI 6 to 13). Oestrogen-only HT significantly increased the risk of venous thrombo-embolism (after one to two years' use: AR 5 per 1000, 95% CI 2 to 10; after 7 years' use: AR 21 per 1000, 95% CI 16 to 28), stroke (after 7 years' use: AR 32 per 1000, 95% CI 25 to 40) and gallbladder disease (after seven years' use: AR 45 per 1000, 95% CI 36 to 57) but did not significantly increase the risk of breast cancer. Among women aged over 65 years who were relatively healthy and taking continuous combined HT, there was a statistically significant increase in the incidence of dementia (after 4 years' use: AR 18 per 1000, 95% CI 11 to 30). Among women with cardiovascular disease, long term use of combined continuous HT significantly increased the risk of venous thrombo-embolism (at one year: AR 9 per 1000, 95% CI 3 to 29). Women taking HT had a significantly decreased incidence of fractures with long term use (after 5.6 years of combined HT: AR 86 per 1000, 95% CI 79 to 84; after 7.1 years' use of oestrogen-only HT: AR 102 per 1000, 95% CI 91 to 112). Risk of fracture was the only outcome for which there was strong evidence of clinical benefit from HT. There was no strong evidence that HT has a clinically meaningful impact on the incidence of colorectal cancer.One trial analysed subgroups of 2839 relatively healthy 50 to 59 year old women taking combined continuous HT and 1637 taking oestrogen-only HT versus similar-sized placebo groups. The only significantly increased risk reported was for venous thrombo-embolism in women taking combined continuous HT: their absolute risk remained low, at less than 1/500. However, other differences in risk cannot be excluded as this study was not designed to have the power to detect differences between groups of women within 10 years of the menopause.

AUTHORS' CONCLUSIONS

HT is not indicated for primary or secondary prevention of cardiovascular disease or dementia, nor for preventing deterioration of cognitive function in postmenopausal women. Although HT is considered effective for the prevention of postmenopausal osteoporosis, it is generally recommended as an option only for women at significant risk, for whom non-oestrogen therapies are unsuitable. There are insufficient data to assess the risk of long term HT use in perimenopausal women or postmenopausal women younger than 50 years of age.

Association of estrogen receptor beta variants and serum levels of estradiol with risk of colorectal cancer: a case control study

Background

Endogenous estrogens may play a vital role in colorectal tumorigenesis. Estrogen receptor beta is the predominant subtype which mediates the biological effect of estrogens, while loss of expression of estrogen receptor beta has been indicated as a common step in the development of colorectal cancer (CRC). Epidemiological studies have revealed several functional polymorphisms of estrogen receptor beta (ESR2) for cancer risk, but relevant study in CRC is limited, particularly in men. This study aimed to investigate the association of circulating estradiol and variations of ESR2 with CRC risk in men.

Methods

We initiated a case–control study consisting of 390 patients with CRC and 445 healthy controls in men only. We genotyped ESR2 single nucleotide polymorphisms (SNPs) rs1256049 and rs4986938 and measured serum estradiol concentration using chemilluminescence immunoassay. Multivariable logistic regression model was performed to evaluate the associations between these variables and CRC risk.

Results

ESR2 rs1256049 CT/TT genotypes were associated with reduced risk of CRC (odds ratio [OR], 0.7, 95% confidence interval [CI], 0.5–1.0), while rs4986938 CT/TT genotypes were associated with increased risk of CRC (OR, 1.5, 95% CI, 1.0–2.1). In addition, the CRC risk increased with the number of risk genotypes of these two SNPs in a dose–response manner (P_trend, 0.003). Specifically, subjects carrying risk genotypes of both SNPs had the highest risk of CRC (OR, 2.0, 95% CI, 1.3–3.3.). Moreover, serum estradiol concentration alone was associated with risk of CRC in men (OR, 1.2, 95% CI, 1.0–1.3). However, individuals presenting both rs4986938 CT/TT genotypes and high level of serum estradiol had a high risk of CRC (OR, 2.3, 95% CI, 1.4–3.9), compared with those presenting CC genotype and low level of serum estradiol. The similar joint results were not observed for SNP rs1256049.

Conclusions

These results suggest that endogenous estrogen and genetic variations in ESR2 may individually, or more likely jointly, affect CRC risk in male Han Chinese population, while larger studies are needed to validate our findings.