Hormone replacement therapy, body mass, and the risk of colorectal cancer among postmenopausal women from Germany

The underestimated impact of excess body weight on colorectal cancer risk: Evidence from the UK Biobank cohort

BACKGROUND

The association between excess weight and colorectal cancer (CRC) risk may have been underestimated due to potential weight loss during pre-clinical sojourn time of CRC. We aimed to investigate this association and the corresponding population attributable fraction (PAF), accounting for prediagnostic weight loss.

METHODS

Data from the UK Biobank prospective cohort were used. Multivariable adjusted hazard ratios (HR) and their 95% confidence intervals (CI) for various periods of follow-up and the corresponding PAF of excess weight were calculated.

RESULTS

During a median of 10.0 years of follow-up, of 453,049 participants, 4794 developed CRC. The excess weight-CRC association became substantially stronger with including increasing lengths of follow-up in the analyses and further excluding the initial years of follow-up. HRs (95% CIs) for overweight and obesity were 1.06 (0.97-1.16) and 1.14 (1.03-1.26) after 7 years of follow-up, 1.13 (1.05-1.21) and 1.23 (1.14-1.33) when including complete follow-up length, and 1.26 (1.12-1.43) and 1.42 (1.24-1.63) when excluding the initial 7 years of follow-up. The corresponding PAFs of excess weight were estimated as 6.8%, 11.3%, and 19.0%, respectively.

CONCLUSIONS

Comprehensive consideration of the potential effect of prediagnostic weight loss discloses a much stronger impact of excess body weight on CRC risk than previously assumed.

Hormone replacement therapy in relation to the risk of colorectal cancer in women by BMI: a multicentre study with propensity score matching

BACKGROUND

Epidemiological evidence about hormone replacement therapy and colorectal carcinogenesis by demographic and clinical traits remains unclear. We aimed to assess this postulated association in a large multicentre study and further explore the modification effect by BMI and others.

METHODS

We retrospectively collected records of women diagnosed with colorectal cancer (CRC) at the age of 50 years and older during 2014-2017 and their HRT dispensing prior to CRC diagnosis in three tertiary hospitals in China. CRC cases were matched with controls at a ratio of 1:3 using nearest neighbour propensity scores matching to better control for the remaining imbalance between groups, which generated a total of 824 cases with 2472 controls.

RESULTS

Our study confirmed the inversed association between colorectal cancer risk and hormone replacement therapy (OR, 0.62; 95% CI, 0.54-0.75), which was more prominent among women having multiple HRT dispenses (OR, 0.60; 95% CI, 0.52-0.76). Furthermore, significant associations were consistently observed for the short-term (OR, 0.69; 95% CI, 0.57-0.88), middle-term (OR, 0.51; 95% CI, 0.41-0.66), and long-term HRT users (OR, 0.70; 95% CI, 0.43-0.90). Estrogen-related regimen reduced CRC risk more than progestogen-only. We, for the first time, found that the modifying effect of BMI on HRT use and CRC risk was in different ways when BMI was categorized by a medium level of 27.

CONCLUSION

Our findings mainly suggest that there might be a different mechanism for the reversed association between HRT and colorectal tumorigenesis by BMI level, providing thoughts on clinical treatment of CRC.

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.

DNA methylation profiling to explore colorectal tumor differences according to menopausal hormone therapy use in women

Aim: Use of menopausal hormone therapy (MHT) has been associated with a reduced risk for colorectal cancer, but mechanisms underlying this relationship are not well understood. In the colon, MHT appears to act through estrogen receptor β (ERβ) which may influence DNA methylation by binding to DNA. Using genome-wide methylation profiling data, we aimed to identify genes that may be differentially methylated according to MHT use. Materials & methods: DNA methylation was measured using Illumina HumanMethylation450k arrays in two independent tumor sample sets of colorectal cancer patients. Differential methylation was determined using R/limma. Results: In the discovery analysis, two CpG sites showed differential DNA methylation according to MHT use, both were not replicated. In stratified analyses, 342 CpG sites were associated with current MHT use only in ERβ-positive tumors. Conclusion: The suggestive findings of differential methylation according to current MHT use in ERβ-positive tumors warrant further investigation.

MOTS-c peptide regulates adipose homeostasis to prevent ovariectomy-induced metabolic dysfunction

The postmenopausal state is associated with an increased risk of metabolic disorder including reduced energy expenditure and weight gain, leading to higher cardiovascular and cancer risks among other diseases. Mitochondrial-derived peptide (MOTS-c) is a 16-amino acid peptide encoded by mitochondrial DNA. Here, we showed that MOTS-c treatment in mice prevented ovariectomy-induced obesity and insulin resistance. After ovariectomy, low levels of estrogens increased fat mass overload and disturbed normal adipose function, forcing the development of insulin resistance. MOTS-c treatment increased brown fat activation and reduced OVX-induced fat accumulation and inflammatory invasion in white adipose tissue, which contributes to the lower level of fatty acid in serum and liver. Moreover, MOTS-c activated AMPK pathway to improve energy dissipation and insulin sensitivity. And a blocker of AMPK pathway was found to attenuate the role of MOTS-c in the regulation of adipocyte lipid metabolism. In conclusion, MOTS-c is a high potential candidate for chronic treatment of menopausal induced metabolic dysfunction. KEY MESSAGES: • MOTS-c prevents ovariectomy (OVX)-induced body weight gain and insulin resistance. • MOTS-c reduces fat mass and suppresses inflammatory response under OVX condition. • MOTS-c sustains the activity of the brown adipose under OVX condition. • MOTS-c mediates AMPK pathway activation to control adipose metabolic homeostasis.

Leptin gene variants and colorectal cancer risk: Sex-specific associations

BACKGROUND

High levels of serum leptin and low levels of serum adiponectin are strongly correlated with obesity, a well-established risk factor for colorectal cancer (CRC). Growing evidence suggests that dysregulation of leptin and adiponectin levels may play an etiological role in colorectal carcinogenesis. We evaluated 20 candidate variants in 4 genes previously shown to alter serum leptin and adiponectin levels for associations with obesity (BMI>30 kg/m2) and CRC risk.

METHODS

We analyzed 6,246 CRC cases and 7,714 population-based controls from 11 studies within the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Associations of each variant with obesity or CRC were evaluated using multivariate logistic regression models stratified by sex and adjusted for age, a study variable, and the first three principal components of genetic ancestry. Gene-specific False Discovery Rate (FDR)-adjusted p-values <0.05 denoted statistical significance.

RESULTS

Two variants in the leptin gene showed statistically significant associations with CRC among women: LEP rs2167270 (OR = 1.13, 95% CI: 1.06-1.21) and LEP rs4731426 (OR = 1.09, 95% CI: 1.02-1.17). These associations remained significant after adjustment for obesity, suggesting that leptin SNPs may influence CRC risk independent of obesity. We observed statistically significant interactions of the leptin variants with hormone replacement therapy (HRT) for CRC risk; these variant associations were strengthened when analyses were restricted to post-menopausal women with low estrogen exposure, as estimated by 'never use' of HRT and/or non-obese BMI. No variants were associated with CRC among men.

CONCLUSIONS

Leptin gene variants may exhibit sex-specific associations with CRC risk. Endogenous and exogenous estrogen exposure may modify the association between these variants, leptin levels, and CRC risk.

Results from a retrospective analysis of colonoscopies for Inflammatory bowel disease and colorectal cancer in a Lebanese tertiary care centre

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBDs) and colorectal cancer have an increased impact on the Lebanese population's morbidity and mortality. This study evaluated the situation of IBD and colorectal cancer at a tertiary hospital centre in Lebanon.

METHODS

1007 patients underwent colonoscopy over a period of 12 months by qualified physicians. 91 patients were excluded from the study. Biopsy results were divided into normal versus abnormal colonic tissue. The abnormal section was further subdivided into number of polyps, IBD, dysplasia and cancer.

RESULTS

Out of 916 individuals included, 61 cases of Crohn's colitis (CC) (6.7%) and 24 cases of ulcerative colitis (UC) (2.7%) were identified. A total of 92 cases of colorectal cancer (10.04%) were also identified. There was a slight male predominance in both groups of IBD without any statistical significance. One statistical significance was reported in favour to age<50 years in both IBD groups with a mean age of 37.9±9.7 years and 34.4±6.4 years for CC and UC, respectively. The incidence of granuloma in the CC group was 8.9% without any correlation compared with age or gender. No correlation was made between colorectal cancer and the existence of any IBD type. The data showed that age >50 years and male gender significantly correlate with an increased incidence of precancerous and cancerous polyps in the colon. They significantly correlate with adenocarcinoma. The estimated incidence of colorectal cancer, CC and UC was 54.1, 35.8 and 14.1 per 100 000, respectively, with a denominator of 169 959 patients per year.

CONCLUSION

Within the limitations of this study, the incidence of colorectal cancer and IBD falls in the high range compared with similar European and American studies. Our data are biased because of the tertiary centre setting but they can be considered as base for further investigations.

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.

Comparison of anthropometric measures as predictors of cancer incidence: A pooled collaborative analysis of 11 Australian cohorts

Obesity is a risk factor for cancer. However, it is not known if general adiposity, as measured by body mass index (BMI) or central adiposity [e.g., waist circumference (WC)] have stronger associations with cancer, or which anthropometric measure best predicts cancer risk. We included 79,458 men and women from the Australian and New Zealand Diabetes and Cancer Collaboration with complete data on anthropometry [BMI, WC, Hip Circumference (HC), WHR, waist to height ratio (WtHR), A Body Shape Index (ABSI)], linked to the Australian Cancer Database. Cox proportional hazards models assessed the association between each anthropometric marker, per standard deviation and the risk of overall, colorectal, post-menopausal (PM) breast, prostate and obesity-related cancers. We assessed the discriminative ability of models using Harrell's c-statistic. All anthropometric markers were associated with overall, colorectal and obesity-related cancers. BMI, WC and HC were associated with PM breast cancer and no significant associations were seen for prostate cancer. Strongest associations were observed for WC across all outcomes, excluding PM breast cancer for which HC was strongest. WC had greater discrimination compared to BMI for overall and colorectal cancer in men and women with c-statistics ranging from 0.70 to 0.71. We show all anthropometric measures are associated with the overall, colorectal, PM breast and obesity-related cancer in men and women, but not prostate cancer. WC discriminated marginally better than BMI. However, all anthropometric measures were similarly moderately predictive of cancer risk. We do not recommend one anthropometric marker over another for assessing an individuals' risk of cancer.

Associations of hormone replacement therapy and oral contraceptives with risk of colorectal cancer defined by clinicopathological factors, beta-catenin alterations, expression of cyclin D1, p53, and microsatellite-instability

Background

Postmenopausal hormone therapy (HRT) and oral contraceptive (OC) use have in several studies been reported to be associated with a decreased colorectal cancer (CRC) risk. However, data on the association between HRT and OC and risk of different clinicopathological and molecular subsets of CRC are lacking. The aim of this molecular pathological epidemiology study was therefore to evaluate the associations between HRT and OC use and risk of specific CRC subgroups, overall and by tumour site.

Method

In the population-based prospective cohort study Mamö Diet and Cancer, including 17035 women, 304 cases of CRC were diagnosed up until 31 December 2008. Immunohistochemical expression of beta-catenin, cyclin D1, p53 and MSI-screening status had previously been assessed in tissue microarrays with tumours from 280 cases. HRT was assessed as current use of combined HRT (CHRT) or unopposed oestrogen (ERT), and analysed among 12583 peri-and postmenopausal women. OC use was assessed as ever vs never use among all women in the cohort. A multivariate Cox regression model was applied to determine hazard ratios for risk of CRC, overall and according to molecular subgroups, in relation to HRT and OC use.

Results

There was no significantly reduced risk of CRC by CHRT or ERT use, however a reduced risk of T-stage 1–2 tumours was seen among CHRT users (HR: 0.24; 95% CI: 0.09-0.77).

Analysis stratified by tumour location revealed a reduced overall risk of rectal, but not colon, cancer among CHRT and ERT users, including T stage 1–2, lymph node negative, distant metastasis-free, cyclin D1 - and p53 negative tumours.

In unadjusted analysis, OC use was significantly associated with a reduced overall risk of CRC (HR: 0.56; 95% CI: 0.44-0.71), but this significance was not retained in adjusted analysis (HR: 1.05: 95% CI: 0.80-1.37). A similar risk reduction was seen for the majority of clinicopathological and molecular subgroups.

Conclusion

Our findings provide information on the relationship between use of HRT and OC and risk of clinicopathological and molecular subsets of CRC.

Meta-analyses of colorectal cancer risk factors

PURPOSE

Demographic, behavioral, and environmental factors have been associated with increased risk of colorectal cancer (CRC). We reviewed the published evidence and explored associations between risk factors and CRC incidence.

METHODS

We identified 12 established non-screening CRC risk factors and performed a comprehensive review and meta-analyses to quantify each factor's impact on CRC risk. We used random-effects models of the logarithms of risks across studies: inverse-variance weighted averages for dichotomous factors and generalized least squares for dose-response for multi-level factors.

RESULTS

Significant risk factors include inflammatory bowel disease (RR = 2.93, 95 % CI 1.79-4.81); CRC history in first-degree relative (RR = 1.80, 95 % CI 1.61-2.02); body mass index (BMI) to overall population (RR = 1.10 per 8 kg/m(2) increase, 95 % CI 1.08-1.12); physical activity (RR = 0.88, 95 % CI 0.86-0.91 for 2 standard deviations increased physical activity score); cigarette smoking (RR = 1.06, 95 % CI 1.03-1.08 for 5 pack-years); and consumption of red meat (RR = 1.13, 95 % CI 1.09-1.16 for 5 servings/week), fruit (RR = 0.85, 95 % CI 0.75-0.96 for 3 servings/day), and vegetables (RR = 0.86, 95 % CI 0.78-0.94 for 5 servings/day).

CONCLUSIONS

We developed a comprehensive risk modeling strategy that incorporates multiple effects to predict an individual's risk of developing CRC. Inflammatory bowel disease and history of CRC in first-degree relatives are associated with much higher risk of CRC. Increased BMI, red meat intake, cigarette smoking, low physical activity, low vegetable consumption, and low fruit consumption were associated with moderately increased risk of CRC.

Clotting factor gene polymorphisms and colorectal cancer risk

PURPOSE

Increased coagulation has been associated with cancer onset and progression. Mainly small studies have addressed the association between clotting factor gene polymorphisms and the onset of colorectal cancer. We examined the association between six well-known clotting factor gene polymorphisms and colorectal cancer risk in a large case-control study.

PATIENTS AND METHODS

Factor V Leiden (rs6025), prothrombin G20210A (rs1799963), PAI-1 4G/5G (rs1799889), MTHFR 677C>T (rs1801133), fibrinogen gamma 10034C>T (rs2066865), and factor XIII Val34Leu (rs5985) were genotyped in 1,801 patients with colorectal cancer and 1,853 healthy controls from a large German population-based study. The risk of colorectal cancer associated with gene variants was determined by calculating odds ratios (ORs) and their 95% CIs using logistic regression.

RESULTS

Homozygous carriers of the prothrombotic factor V Leiden polymorphism showed a 5.8-fold increased risk (95% CI, 1.69 to 19.72) for colorectal cancer compared with noncarriers. A 30% reduced risk was found for heterozygous carriers of factor V Leiden (OR = 0.68; 95% CI, 0.52 to 0.90) and prothrombin G20210A (OR = 0.69; 95% CI, 0.49 to 0.96), implying an advantage for slightly increased thrombin generation. Carriers of the antithrombotic factor XIII Val34Leu polymorphism showed a 15% reduced risk of developing colorectal cancer (OR = 0.85; 95% CI, 0.74 to 0.97) compared with noncarriers. Our results did not support an effect of PAI-1 4G/5G, MTHFR 677C>T, and fibrinogen gamma 10034C>T on colorectal cancer risk.

CONCLUSION

Our results support a role of clotting factor polymorphisms and thereby the coagulation system in the risk of colorectal cancer.

Colorectal cancer: what should patients and families be told to lower the risk of colorectal cancer?

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the United States. CRC, however, is potentially preventable, and several strategies may be employed to decrease the incidence of and mortality from CRC. Understanding of individual risk and adherence to screening and surveillance recommendations undoubtedly will reduce CRC-associated deaths. Several natural and synthetic chemopreventive agents may prove effective for both primary and secondary CRC chemoprevention. Finally, dietary modifications (ie, increased dietary fiber, fruits and vegetables, and decreased red meat) and other lifestyle changes (i.e., increased physical activity, weight maintenance, avoidance of smoking, and moderation of alcohol intake) also may lower the risk of developing CRC.

Epidemiology of colorectal cancer in Asia

The prevalence of colorectal cancer is increasing in Asia. However, the age-standardized rate has reached a plateau in some countries. Some studies have shown a male predominance difference and increasing risk in the elderly, but not in the younger population. 'Right shifting' of colorectal cancer, not accountable by difference in age or the indications for endoscopic examination, has also been noted. Westernized diet is associated with colorectal cancer, but controversy remains on how it causes colorectal cancer. Alcohol consumption, obesity, diabetes mellitus, consumption of red and processed meat and cigarette smoking are linked to bowel cancer epidemiologically. Only high dietary calcium has a consistent negative (or 'protective') effect. The efficacy of fish oil, vitamin D, soy, phytoestrogens, folate, methionine, riboflavin and vitamin B6 has not been established. Aspirin and non-steroidal anti-inflammatory drugs use decrease risk of colorectal cancer after 5-10 years of use. There is no evidence for a detrimental effect of proton pump inhibitors or benefit of statins in colorectal cancer. In conclusion, there is a rising trend and prevalence of colorectal cancer in Asia. Dietary modification or supplementation may not be effective in preventing colorectal cancer. Surveillance of colorectal cancer in high-risk groups, according to current recommendation, is probably most effective.

Use of hormone replacement therapy and the risk of colorectal cancer

PURPOSE

Estrogen/progestin replacement therapy is prescribed to women in menopause for purposes of postmenopausal symptom control or prevention of hormone deficiency-related diseases such as osteoporosis. Such treatments have formerly been shown to be associated with lower colorectal cancer risk in an as yet unknown mechanism.

PATIENTS AND METHODS

The Molecular Epidemiology of Colorectal Cancer study was a population-based case-control study in northern Israel of patients with colorectal cancer who were diagnosed between 1998 and 2006, and age-, sex-, clinic-, and ethnicity-matched population controls. Use of hormone replacement therapy (HRT) was assessed using a structured interview and validated by studying prescription records in a subset of patients for whom they were available.

RESULTS

Two thousand four hundred sixty peri/postmenopausal women were studied from among 2,648 patients with colorectal cancer and 2,566 controls. The self-reported use of HRT was associated with a significantly reduced relative risk of colorectal cancer (odds ratio [OR], 0.67; 95% CI, 0.51 to 0.89). This association remained significant after adjustment for age, sex, use of aspirin and statins, sports activity, family history of colorectal cancer, ethnic group, and level of vegetable consumption (OR, 0.37; 95% CI, 0.22 to 0.62). Statistically significant interactions were seen between use of HRT and use of aspirin and involvement in sports activity. Using pharmacy data, only users of combined oral preparations demonstrated a significant negative association with colorectal cancer.

CONCLUSION

The use of oral HRT was associated with a 63% relative reduction in the risk of colorectal cancer in postmenopausal women after adjustment for other known risk factors. This effect was not found in aspirin users and women with intensive sports participation.

Hormone therapy in relation to survival from large bowel cancer

Epidemiologic studies of hormone therapy (HT) and colorectal cancer incidence consistently show an inverse association; however, few studies have considered prediagnostic use of HT on mortality among colorectal cancer patients. We evaluated the relationship of HT and survival among a population-based cohort of women with large bowel cancer. Cases (n=1,297) were newly diagnosed with invasive cancer of the colon or rectum, aged 40-74 years at diagnosis, who were identified by Wisconsin's statewide registry (1988-1991; 1997-2001) for two case-control studies. Information on HT use and other colorectal cancer risk factors was collected by standardized interview. There were 507 deaths (274 of these attributable to colorectal cancer) over 8.4 years of follow-up through December 2005. Hormone use was not associated with colorectal cancer mortality (adjusted hazard rate ratio=1.09, confidence interval=0.81-1.47). Colorectal cancer specific mortality was not associated with HT when considered separately by preparation type. Stage did not modify this relationship. Long-term HT was weakly positively associated with increased mortality after diagnosis of proximal colon, but not distal colon cancer. Because we detected no differences in survival among users of HT compared to non-users, the results suggest that HT use may affect only the incidence of some colorectal tumors.

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

BACKGROUND

In separate Women's Health Initiative randomized trials, combined hormone therapy with estrogen plus progestin reduced colorectal cancer incidence but estrogen alone in women with hysterectomy did not. We now analyze features of the colorectal cancers that developed and examine the survival of women following colorectal cancer diagnosis in the latter trial.

PARTICIPANTS AND METHODS

10,739 postmenopausal women who were 50 to 79 years of age and had undergone hysterectomy were randomized to conjugated equine estrogens (0.625 mg/d) or matching placebo. Colorectal cancer incidence was a component of the monitoring global index of the study but was not a primary study endpoint. Colorectal cancers were verified by central medical record and pathology report review. Bowel exam frequency was not protocol defined, but information on their use was collected.

RESULTS

After a median 7.1 years, there were 58 invasive colorectal cancers in the hormone group and 53 in the placebo group [hazard ratio, 1.12; 95% confidence interval (95% CI), 0.77-1.63]. Tumor size, stage, and grade were comparable in the two randomization groups. Bowel exam frequency was also comparable in the two groups. The cumulative mortality following colorectal cancer diagnosis among women in the conjugated equine estrogen group was 34% compared with 30% in the placebo group (hazard ratio, 1.34; 95% CI, 0.58-3.19).

CONCLUSIONS

In contrast to the preponderance of observational studies, conjugated equine estrogens in a randomized clinical trial did not reduce colorectal cancer incidence nor improve survival after diagnosis.