Leisure-time physical activity, body size, and colon cancer in women. Nurses' Health Study Research Group

Recreational physical activity and breast cancer risk by menopausal status and tumor hormone receptor status: results from the Nurses' Health Studies

PURPOSE

Physical activity is associated with lower breast cancer risk, especially in postmenopausal women. Associations in premenopausal women are less well established.

METHODS

We evaluated recreational physical activity and breast cancer risk in the Nurses' Health Study (NHS) and NHSII (187,278 women; n = 12,785 breast cancers; follow-up: NHS = 1986-2016, NHSII = 1989-2017) by menopausal status and estrogen (ER) and progesterone (PR) receptor status. Physical activity was evaluated as updated cumulative average of metabolic equivalent of task (MET)-h/week. Cox proportional hazards models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Recreational physical activity was inversely associated with breast cancer risk in pre- and postmenopausal women. Higher activity levels were associated with lower risk of ER+/PR + breast cancer in both pre- and postmenopausal women (e.g., total recreational activity, ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83, 95%CI = (0.70-0.99), postmenopausal HR = 0.86 (0.78-0.95); pheterogeneity = 0.97). Results were attenuated with adjustment for current body mass index (BMI) among postmenopausal, but not premenopausal, women (e.g., ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83 (0.69-0.98); postmenopausal HR = 0.95 (0.85-1.05); pheterogeneity = 0.99). In analyses of moderate-vigorous activity and breast cancer risk, no heterogeneity by menopausal status was observed (phet ≥ 0.53; e.g., ≥ 27 vs < 3 MET-h/week, ER+/PR+, premenopausal HR = 0.88 (0.69-1.11); postmenopausal HR = 0.71 (0.58-0.88). No associations were observed for ER-/PR- disease.

CONCLUSIONS

Recreational physical activity was associated with lower breast cancer risk in both pre- and postmenopausal women, supporting recreational physical activity as an accessible, modifiable exposure associated with reduced breast cancer risk regardless of menopausal status.

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Abdominal obesity and digestive system cancer: a systematic review and meta-analysis of prospective studies

BACKGROUND

The diagnostic criteria for abdominal obesity are usually waist circumference or waist-to-hip ratio. The magnitude of the risks for cancers of the digestive system and abdominal obesity is unknown. To assess whether abdominal obesity increases the risk of digestive cancer, we conducted a systematic review and meta-analysis of prospective cohort studies in a database.

METHODS

PubMed, Embase, and Web of Science databases were searched from their inception to December 2022. The 9-star Newcastle Ottawa Scale was used to assess  study quality. Pooled relative risks and 95% confidence intervals were calculated using fixed or random effect models respectively. The stability of the results was explored by one-by-one exclusion. Subgroup analysis was conducted to explore sources of heterogeneity. Publication bias was evaluated by Begg's and Egger's tests.

RESULTS

A total of 43 cohort studies were included. There were 42 and 31 studies in the meta-analysis of waist circumference and waist-to-hip ratio on digestive system cancer, respectively. The results of the meta-analysis revealed that the greater waist circumference and waist-to-hip ratio were correlated with increased incidence of digestive system cancers: waist circumference: RR 1.48, 95% CI 1.38-1.59, p < 0.001; waist-to-hip ratio: RR 1.33, 95% CI 1.28-1.38, p = 0.001. Subgroup analysis by cancer type showed that higher WC and WHR would increase the prevalence of LC, PC, GC, EC, and CRC. The sensitivity analysis was conducted by a one-by-one elimination method, and the results of the meta-analysis remained stable. It is proved that the results were robust by the trim-and-fill method.

CONCLUSIONS

There was evidence to suggest that abdominal obesity increased the incidence of digestive cancer, it is necessary to take appropriate measures to reduce abdominal obesity. Waist circumference and waist-to-hip ratio may be better predictors of digestive system cancers. However, the association between waist circumference and digestive system cancer was greater, so more attention should be paid to measuring abdominal obesity with waist circumference.

Associations of Albumin and BMI with Colorectal Cancer Risk in the Southern Community Cohort Study: a Prospective Cohort Study

BACKGROUND

Obesity may increase colorectal cancer (CRC) risk through mechanisms of increased inflammation. Although BMI is the most used adiposity indicator, it may less accurately measure adiposity in Black populations. Herein, we investigate associations between BMI, low albumin as an inflammation biomarker, and CRC risk in a racially diverse cohort.

METHODS

Participant data arise from 71,141 participants of the Southern Community Cohort Study, including 724 incident CRC cases. Within the cohort, 69% are Black. Blood serum albumin concentrations, from samples taken at enrollment, were available for 235 cases and 567 controls. Controls matched by age, sex, and race were selected through incidence density sampling. Cox proportional hazards calculated BMI and CRC risk associations (hazard ratios [HRs]; 95% confidence intervals [CIs]. Conditional logistic regression calculated albumin and CRC risk associations (odds ratios [ORs]; 95%CIs).

RESULTS

Underweight, but not overweight or obese, compared to normal BMI was associated with increased CRC risk (HR:1.75, 95%CI:1.00-3.09). Each standard deviation increase of albumin was associated with decreased CRC risk, particularly for those who self-identified as non-Hispanic Black (OR: 0.56, 95%CI:0.34-0.91), or female (OR:0.54, 95%CI:0.30-0.98), but there was no evidence for interaction by these variables (p-interactions > 0.05). Moreover, albumin concentration was lower in Black than White participants. Mediation analysis suggested that the relation between albumin and CRC was not mediated by BMI.

CONCLUSIONS

Null associations of overweight/obesity with CRC risk demonstrates limited utility of BMI, especially among Black populations. Low albumin may indicate CRC risk. In Black individuals, albumin may better predict adiposity related risks than BMI.

Association between regular physical activity and lower incidence of colorectal cancer in patients with diabetes mellitus: a nationwide cohort study

AIM

The aim of this work was to investigate the association between changes in physical activity (PA) status and the development of colorectal cancer (CRC) in patients with diabetes.

METHOD

This nationwide population study included 1 439 152 patients with diabetes who underwent a health screening provided by the Korean National Health Insurance Service between January 2009 and December 2012 and a follow-up screening after 2 years. Based on changes in PA status, participants were categorized into four groups: remained inactive, remained active, active-to-inactive and inactive-to-active.

RESULTS

During the median follow-up period of 5.2 years, 38 244 new cases of CRC were diagnosed. Compared with the remained inactive group, among the three other groups, the remained active group had the lowest risk of CRC [adjusted hazard ratio (aHR) 0.93; 95% CI 0.90-0.96], followed by the inactive-to-active group (aHR 0.97; 95% CI 0.94-1.00) and active-to-inactive group (aHR 0.99; 95% CI 0.96-1.02), after adjusting for confounding variables (p = 0.0007). This reduction in cancer incidence in the remained active group was observed for both rectal cancer (aHR 0.87, 95% CI 0.79-0.95) and colon cancer (aHR 0.93, 95% CI 0.90-0.97), irrespective of sex. In terms of the intensity and amount of PA, moderate intensity PA was the most effective, and a positive correlation was found between the amount of PA and the reduction in CRC incidence.

CONCLUSION

Regular PA was independently associated with a decreased risk of CRC in patients with diabetes. The intensity and amount of physical activity both play a role in reducing the risk.

Body size over the adult life course and the risk of colorectal cancer among postmenopausal women

OBJECTIVE

To assess the associations among several anthropometric measures, as well as BMI trajectories and colorectal cancer (CRC) risk in older women.

DESIGN

Prospective cohort study.

SETTING

Forty clinical centres in the USA.

PARTICIPANTS

Totally, 79 034 postmenopausal women in the Women's Health Initiative Observational Study.

RESULTS

During an average of 15·8 years of follow-up, 1514 CRC cases were ascertained. Five BMI trajectories over 18-50 years of age were identified using growth mixture model. Compared with women who had a normal BMI at age 18, women with obesity at age 18 had a higher risk of CRC (HR 1·58, 95 % CI 1·02, 2·44). Compared with women who kept relatively low normal body size during adulthood, women who progressed from normal to obesity (HR 1·29, 95 % CI 1·09, 1·53) and women who progressed from overweight to obesity (HR 1·37, 95 % CI 1·13, 1·68) had higher CRC risks. A weight gain > 15 kg from age 18 to 50 (HR 1·20, 95 % CI 1·04, 1·40) and baseline waist circumference > 88 cm (HR 1·33, 95 % CI 1·19, 1·49) were associated with higher CRC risks, compared with stable weight and waist circumference ≤ 88 cm, respectively.

CONCLUSION

Women who have a normal weight in early adult life and gain substantial weight later, as well as those who are persistently heavy over adulthood, demonstrated a higher risk of developing CRC. Our study highlights the importance of maintaining a healthy body weight over the life course for reducing the risk of developing CRC in women.

Physical activity and breast cancer survival: results from the Nurses' Health Studies

BACKGROUND

Physical activity is generally associated with better outcomes following diagnosis; however, few studies have evaluated change in pre- to postdiagnosis activity and repeated measures of activity by intensity and type.

METHODS

We evaluated physical activity and survival following a breast cancer diagnosis in the Nurses' Health Study and Nurses' Health Study II (n = 9308 women, n = 1973 deaths). Physical activity was evaluated as updated cumulative average of metabolic equivalent of task (MET)-h/wk (assigned per activity based on duration and intensity) and change in pre- to postdiagnosis activity. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Higher postdiagnosis activity was inversely associated with breast cancer-specific mortality in categories from ≥9 MET-h/wk (vs <3 MET h/wk, HR≥9 to <18 = 0.74 [95% CI = 0.55 to 0.99]; HR≥27 = 0.69 [95% CI = 0.50 to 0.95]; Ptrend = .04) and all-cause mortality from ≥3 MET-h/wk (HR≥3 to <9 = 0.73 [95% CI = 0.61 to 0.88]; HR≥27 = 0.51 [95% CI = 0.41 to 0.63]; Ptrend < .001). Associations were predominantly observed for estrogen receptor-positive tumors and in postmenopausal women. Walking was associated with lower risk of all-cause mortality (≥9 vs <3 MET-h/wk, HR= 0.69 [95% CI = 0.57 to 0.84]) as was strength training. Relative to stable activity pre- to postdiagnosis (±3 MET-h/wk), increases from ≥3 to 9 MET-h/wk were associated with lower all-cause mortality risk (Ptrend < .001). Results were robust to adjustment for prediagnosis physical activity.

CONCLUSIONS

Physical activity was associated with lower risk of death following diagnosis. Increased pre- to postdiagnosis activity corresponding to at least 1-3 h/wk of walking was associated with lower risk of death. These results provide further impetus for women to increase their activity after a breast cancer diagnosis, though reverse causation cannot be fully excluded.

Low-Intensity Exercise Modulates Gut Microbiota to Fight Against Radiation-Induced Gut Toxicity in Mouse Models

Radiation-induced gastrointestinal (GI) tract toxicity halts radiotherapy and degrades the prognosis of cancer patients. Physical activity defined as “any bodily movement produced by skeletal muscle that requires energy expenditure” is a beneficial lifestyle modification for health. Here, we investigate whether walking, a low-intensity form of exercise, could alleviate intestinal radiation injury. Short-term (15 days) walking protected against radiation-induced GI tract toxicity in both male and female mice, as judged by longer colons, denser intestinal villi, more goblet cells, and lower expression of inflammation-related genes in the small intestines. High-throughput sequencing and untargeted metabolomics analysis showed that walking restructured the gut microbiota configuration, such as elevated Akkermansia muciniphila, and reprogramed the gut metabolome of irradiated mice. Deletion of gut flora erased the radioprotection of walking, and the abdomen local irradiated recipients who received fecal microbiome from donors with walking treatment exhibited milder intestinal toxicity. Oral gavage of A. muciniphila mitigated the radiation-induced GI tract injury. Importantly, walking did not change the tumor growth after radiotherapy. Together, our findings provide novel insights into walking and underpin that walking is a safe and effective form to protect against GI syndrome of patients with radiotherapy without financial burden in a preclinical setting.

Colorectal Cancer, Age, and Obesity-Related Comorbidities: A Large Database Study

BACKGROUND AND AIMS

The association between obesity and colorectal cancer (CRC) is well established in older individuals, but evidence is limited in the younger population. The study aims to analyze the relationship of obesity and its related comorbidities in early-onset CRC (E-CRC) and compare it to late-onset CRC (L-CRC).

METHODS

A retrospective, cross-sectional study was performed on average-risk individuals ≥ 20 years who were active patients in the commercial database, IBM Watson Health Explorys in the last 5 years. Individuals with CRC were compared to those without CRC across different age groups (20-39, 40-49, and 50-74 years). Individuals with CRC diagnosed < 50 years (E-CRC) were compared to those with CRC between 50 and 74 years (L-CRC). Variables included sex, smoking, obese BMI, diabetes mellitus type 2 (DM2), hypertension (HTN), and hyperlipidemia (HLD). Since Explorys aggregates population-level, de-identified data, approval from institutional review board was not required.

RESULTS

Among 37,483,140 individuals, 162,150 cases of sporadic CRC were identified. Compared to the general population, obesity and HLD were independent risk factors for CRC across all age groups; DM2, HTN, and smoking were independent risk factors for CRC in men of all age groups and women with L-CRC. Compared to L-CRC, individuals with E-CRC had lower percentages of obesity-related comorbidities.

CONCLUSION

In E-CRC, obesity, DM2, HTN, HLD, and smoking are independent risk factors for CRC among men; obesity and HLD are independent risk factors for CRC in women. These subgroups may benefit from a personalized screening approach to detect early-onset CRC.

Sugar-Sweetened Beverages, Artificially Sweetened Beverages, and Breast Cancer Risk: Results From 2 Prospective US Cohorts

BACKGROUND

Whether consumption of sugar-sweetened beverages (SSBs) or artificially sweetened beverages (ASBs) is associated with the risk of breast cancer is of public health interest.

OBJECTIVES

We sought to evaluate associations between consumption of SSBs and ASBs and risks of total and subtype-specific breast cancer.

METHODS

We followed 82,713 women from the Nurses' Health Study (1980 to 2016) and 93,085 women from the Nurses' Health Study II (1991 to 2017). Cumulatively averaged intakes of SSBs and ASBs from FFQs were tested for associations with incident breast cancer cases and subtypes using Cox regression models. We also evaluated the associations stratified by menopausal status, physical activity, BMI, and alcohol intake.

RESULTS

We documented 11,379 breast cancer cases during 4,655,153 person-years of follow-up. Consumption of SSBs or ASBs was not associated with total breast cancer risk: pooled HRs comparing extreme categories (≥1/day compared with <1/month) were 1.03 (95% CI, 0.95-1.12) and 0.96 (95% CI, 0.91-1.02), respectively. We observed a suggestive interaction by BMI using pooled data (P-interaction = 0.08), where a modestly higher risk of breast cancer with each serving per day increment of SSBs was found in lean women (HR, 1.06; 95% CI, 1.01-1.11) but not among overweight or obese women (HR, 1.00; 95% CI, 0.95-1.06). Moreover, in the pooled, fully adjusted analysis, compared to infrequent consumers (<1/month), those who consumed ≥1 serving of ASBs per day had a lower risk of luminal A breast tumors (HR, 0.90; 95% CI, 0.80-1.01; P-trend = 0.02).

CONCLUSIONS

Although no significant associations were observed overall, consumption of SSBs was associated with a slightly higher risk of breast cancer among lean women. This finding could have occurred by chance and needs confirmation. Our findings also suggest no substantial increase in the risk of breast cancer with consumption of ASBs.

Expression of long non-coding RNA H19 in colorectal cancer patients with type 2 diabetes

The aim of this study was to explore the lncRNAs expression in colorectal cancer (CRC) patients with type 2 diabetes (T2DM) and evaluate the diagnostic value of lncRNAs expression in CRC patients with T2DM. The present study was conducted on two cohorts with CRC patients. The tissues levels of lncRNAs were measured by real-time PCR analysis. The results showed that H19 and MALAT1 expression were higher in CRC tissues than in normal colorectal mucosa (p = 1.59 × 10^-6 and p = 6.95 × 10^-9, respectively), whereas lincRNA-p21 showed lower expression in CRC tissues (p = 1.10 × 10^-4). Logistic regression analysis results indicated that the expression of H19 was significantly lower in CRC patients with T2DM compared with CRC patients without T2DM (p = .032). H19 expression in CRC group without T2DM was significantly associated with hypertension (p = .040). Additionally, the area under the receiver operating characteristic curve of H19 was 0.672 of the group CRC with T2DM, which suggests that H19 could be a useful biomarker and predictive targets for diagnosis of T2DM in CRC patients.

Obesity Has a Stronger Relationship with Colorectal Cancer in Postmenopausal Women than Premenopausal Women

BACKGROUND

To examine the relationship between obesity measured by waist circumference (WC) and body mass index (BMI) and the incidence of colorectal cancer in premenopausal and postmenopausal women.

METHODS

A total of 1,418,180 premenopausal and 4,854,187 postmenopausal women without cancer at baseline and ages over 40 were identified using the Korean National Health Insurance System Cohort during 2009 to 2014. The hazard ratio (HR) for colorectal cancer incidence was assessed according to menopausal state using Cox proportional hazards models.

RESULTS

During a mean follow-up period of 7.2 years, 7,094 and 57,449 colorectal cancer cases occurred in premenopausal and postmenopausal women, respectively. Compared with the reference group (WC 65-75), the HRs [95% confidence interval (CI)] of colorectal cancer in WC <65, 75-85, 85-95, and >95 groups were 1.01 (0.91-1.11), 1.02 (0.97-1.07), 1.09 (1.00-1.18), and 1.31 (1.12-1.52), respectively, in premenopausal women and 1.01 (0.95-1.17), 1.09 (1.07-1.12), 1.19 (1.00-1.18), and 1.30 (1.25-1.35), respectively, in postmenopausal women. Compared with the reference group (BMI 18.5-22.9), HRs (95% CI) for colorectal cancer in BMI <18.5, 23-25, 25-30, and >30 groups were 0.99 (0.87-1.14), 0.99 (0.94-1.06), 0.98 (0.92-1.04), and 1.06 (0.92-1.20), respectively, in premenopausal women. In postmenopausal women, those values were 0.99 (0.93-1.05), 1.05 (1.03-1.08), 1.11 (1.09-1.13), and 1.20 (1.16-1.25), respectively.

CONCLUSIONS

WC is associated with the risk of colorectal cancer in both groups of women, but this association was stronger in postmenopausal women than in premenopausal women. BMI increased the incidence of colorectal cancer only in postmenopausal women IMPACT: Obesity has a stronger relationship with colorectal cancer in postmenopausal women than in premenopausal women.

Body Mass Index and Weight Loss in Metastatic Colorectal Cancer in CALGB (Alliance)/SWOG 80405

Background

In nonmetastatic colorectal cancer, overweight and mild-to-moderately obese patients experience improved outcomes compared with other patients. Obesity’s influence on advanced or metastatic colorectal cancer (mCRC) is relatively unexplored.

Methods

We conducted a prospective body mass index (BMI) companion study in Cancer and Leukemia Group B (now Alliance)/SWOG 80405, a phase III metastatic colorectal cancer (mCRC) treatment trial. BMI was measured at trial registration. Primary and secondary endpoints were overall and progression-free survival, respectively. To minimize confounding by poor and rapidly declining health, we used Cox proportional hazards regression to adjust for known prognostic factors, comorbidities, physical activity, and weight loss during the 6 months prior to study entry. We also examined weight loss prior to enrollment as an independent predictor of patient outcome. All statistical tests were two-sided.

Results

Among 2323 patients with mCRC, there were no statistically significant associations between BMI and overall or progression-free survival (adjusted P_trend = .12 and .40, respectively). Weight loss during the 6 months prior to study entry was associated with shorter overall and progression-free survival; compared with individuals with stable weight ±4.9%, individuals with weight loss greater than 15% experienced an adjusted hazard ratio of 1.52 for all-cause mortality (95% confidence interval [CI] = 1.26 to 1.84; P_trend < .001) and of 1.23 for disease progression or death (95% CI = 1.02 to 1.47; P_trend = .006).

Conclusions

In this prospective study of patients with mCRC, BMI at time of first-line chemotherapy initiation was not associated with patient outcome. Weight loss prior to study entry was associated with increased risk of patient mortality and disease progression.

Association of Obesity With Risk of Early-Onset Colorectal Cancer Among Women

Importance

Colorectal cancer (CRC) incidence and mortality among individuals younger than 50 years (early-onset CRC) are increasing. The reasons for such increases are largely unknown, although the increasing prevalence of obesity may be partially responsible.

Objective

To investigate prospectively the association between obesity and weight gain since early adulthood with the risk of early-onset CRC.

Design, Setting, and Participants

The Nurses' Health Study II is a prospective, ongoing cohort study of US female nurses aged 25 to 42 years at study enrollment (1989). A total of 85 256 women free of cancer and inflammatory bowel disease at enrollment were included in this analysis, with follow-up through December 31, 2011. Validated anthropomorphic measures and lifestyle information were self-reported biennially. Statistical analysis was performed from June 12, 2017, to June 28, 2018.

Exposures

Current body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared), BMI at 18 years of age, and weight gain since 18 years of age.

Main Outcomes and Measures

Relative risk (RR) for incident early-onset CRC.

Results

Among the 85 256 women studied, 114 cases of early-onset CRC were documented (median age at diagnosis, 45 years; interquartile range, 41-47 years) during 1 196 452 person-years of follow-up. Compared with women with a BMI of 18.5 to 22.9, the multivariable RR was 1.37 (95% CI, 0.81-2.30) for overweight women (BMI, 25.0-29.9) and 1.93 (95% CI, 1.15-3.25) for obese women (BMI, ≥30.0). The RR for each 5-unit increment in BMI was 1.20 (95% CI, 1.05-1.38; P = .01 for trend). Similar associations were observed among women without a family history of CRC and without lower endoscopy within the past 10 years. Both BMI at 18 years of age and weight gain since 18 years of age contributed to this observation. Compared with women with a BMI of 18.5 to 20.9 at 18 years of age, the RR of early-onset CRC was 1.32 (95% CI, 0.80-2.16) for women with a BMI of 21.0 to 22.9 and 1.63 (95% CI, 1.01-2.61) for women with a BMI of 23.0 or greater at 18 years of age (P = .66 for trend). Compared with women who had gained less than 5.0 kg or had lost weight, the RR of early-onset CRC was 1.65 (95% CI, 0.96-2.81) for women gaining 20.0 to 39.9 kg and 2.15 (95% CI, 1.01-4.55) for women gaining 40.0 kg or more (P = .007 for trend).

Conclusions and Relevance

Obesity was associated with an increased risk of early-onset CRC among women. Further investigations among men and to elucidate the underlying biological mechanisms are warranted.

Long-Term Physical Activity and Subsequent Risk for Rheumatoid Arthritis Among Women: A Prospective Cohort Study

OBJECTIVE

To evaluate the effects of long-term physical activity on subsequent risk of rheumatoid arthritis (RA) in a prospective cohort study.

METHODS

This study investigated physical activity and RA risk among women from the Nurses' Health Study II (1989-2015). Physical activity exposures and covariates were prospectively obtained using biennial questionnaires. Two rheumatologists independently reviewed the medical records of women who self-reported a new diagnosis of RA on biennial questionnaires and who screened positive for RA based on a supplemental survey. All incident RA cases met the 1987 American College of Rheumatology (ACR) or 2010 ACR/European League Against Rheumatism (EULAR) classification criteria for RA. The primary analysis investigated the long-term cumulative average number of hours spent in recreational physical activity 2-8 years prior to the RA diagnosis, a time span chosen to reduce the potential for reverse causation bias, since early RA affects physical activity prior to diagnosis. Estimated Cox regression hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to assess the risk of RA serologic phenotypes (all, seropositive, or seronegative) in relation to physical activity categories. The analyses were adjusted for body mass index (BMI) at age 18 years and time-varying potential confounders, and the mediating effect of updated BMI on the interaction between physical activity and RA risk was quantified.

RESULTS

Among the 113,366 women analyzed, 506 incident RA cases (67.0% with seropositive RA) were identified during 2,428,573 person-years of follow-up. After adjustment for confounders, including smoking, dietary quality, and BMI at age 18 years, increasing cumulative average total hours of recreational physical activity was associated with a reduced risk of RA, as follows: HR 1.00 for <1 hour/week (reference), HR 1.00 (95% CI 0.78-1.29) for 1 to <2 hours/week, HR 0.92 (95% CI 0.72-1.17) for 2 to <4 hours/week, HR 0.84 (95% CI 0.63-1.12) for 4 to <7 hours/week, and HR 0.67 (95% CI 0.47-0.98) for ≥7 hours/week (P for trend = 0.02). The proportion of the effect between physical activity and RA mediated by updated BMI was 14.0% (P = 0.002) for all RA and 20.0% (P = 0.001) for seropositive RA.

CONCLUSION

Higher levels of physical activity were associated with reduced RA risk. These results add to the literature implicating metabolic factors in the pathogenesis of RA.

Associations of Physical Activity With Survival and Progression in Metastatic Colorectal Cancer: Results From Cancer and Leukemia Group B (Alliance)/SWOG 80405

PURPOSE

Regular physical activity is associated with reduced risk of recurrence and mortality in patients with nonmetastatic colorectal cancer. Its influence on patients with advanced/metastatic colorectal cancer (mCRC) has been largely unexplored.

PATIENTS AND METHODS

We conducted a prospective cohort study nested in Cancer and Leukemia Group B (Alliance)/SWOG 80405 (ClinicalTrials.gov identifier: NCT00265850), a National Cancer Institute-sponsored phase III trial of systemic therapy for mCRC. Within 1 month after therapy initiation, patients were invited to complete a validated questionnaire that reported average physical activity over the previous 2 months. On the basis of responses, we calculated metabolic equivalent task (MET) hours per week to quantify physical activity. The primary end point of the clinical trial and this companion study was overall survival (OS). Secondary end points included progression-free survival (PFS) and first grade 3 or greater treatment-related adverse events. To minimize confounding by poor and declining health, we excluded patients who experienced progression or died within 60 days of activity assessment and used Cox proportional hazards regression analysis to adjust for known prognostic factors, comorbidities, and weight loss.

RESULTS

The final cohort included 1,218 patients. Compared with patients engaged in less than 3 MET hours per week of physical activity, patients engaged in 18 or more MET hours per week experienced an adjusted hazard ratio for OS of 0.85 (95% CI, 0.71 to 1.02; P_Trend = .06) and for PFS of 0.83 (95% CI, 0.70 to 0.99; P_Trend = .01). Compared with patients engaging in less than 9 MET hours per week, patients engaging in 9 or more MET hours per week experienced an adjusted hazard ratio for grade 3 or greater treatment-related adverse events of 0.73 (95% CI, 0.62 to 0.86; P_Trend < .001).

CONCLUSION

Among patients with mCRC in Cancer and Leukemia Group B (Alliance)/SWOG 80405, association of physical activity with OS was not statistically significant. Greater physical activity was associated with longer PFS and lower adjusted risk for first grade 3 or greater treatment-related adverse events.

Voluntary wheel running reduces colon inflammation in female but not male mice fed a high-fat diet

The influence of diet and exercise on intestinal mucus and the spatial organisation of the microbiota is poorly understood. Though, it has been observed that the spatial organisation of the microbiota can be altered extensively in Crohn’s disease and ulcerative colitis. This study aims to investigate the pathophysiological events in mouse colon that are associated with a high fat diet and lack of exercise. Forty-eight, 6-week old C57BL/6NTac male and female mice were fed a normal or high-fat diet for 12 weeks and randomly assigned to free wheel running or sedentary groups. After 12 weeks, animals were sacrificed and distal colon tissue sections with and without faecal material were fixed for histomorphometric analysis, immunohistochemistry for cyclooxygenase-2 and mucin-2, or fluorescent in situ hybridization with the universal bacterial probe EUB338 (5’-GCTGCCTCCCGTAGGAGT-3’). Goblet cell counts and distance between the microbiota and epithelial surface were determined using ImageJ software. All mice had a normal colon morphology except for high-fat fed female mice who ran, demonstrating a reduction of goblet cells that approached significance and a reduced mucin-2 expression. Voluntary wheel running attenuated high-fat diet induced COX-2 expression in female mice only. The distance between the microbiota and epithelial surface remained the same. Taken together, these results show that voluntary wheel running protect against high-fat diet-induced inflammation in the distal colon of female mice and responses to changes in host behaviour may differ between sex.

Physical activity patterns and the risk of colorectal cancer in the Norwegian Women and Cancer study: a population-based prospective study

Introduction

Colorectal cancer (CRC) remains the second most common cancer in women worldwide. Physical activity (PA) has been associated with reduced risk of CRC; however, this has been demonstrated more consistently in men, while results of studies in women have been largely equivocal. We aimed to further examine the relationship between PA patterns and the risk of CRC in women, using repeated measurements.

Methods

We followed participants of the Norwegian Women and Cancer (NOWAC) Study - a nationally representative cohort. Baseline information was available for 79,184 women, and we used this information in addition to follow-up information collected 6–8 years later, for repeated measurement analysis. At enrollment, participants were cancer-free and aged 30–70 years, with a median age of 51 years. We used Cox proportional hazards regression to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During an average of 14.6 years of follow-up and 1.16 million person-years, 885 cases of colon and 426 cases of rectal cancer were identified through linkage to the Norwegian Cancer Registry (median age at diagnosis: 65 years). We found no association between PA level and the risk of colon cancer in baseline or repeated measurements analyses when comparing women with PA level 1–2 to those with PA level 5–6 (reference) (baseline: HR = 0.90, 95% CI 0.66–1.23, p-trend = 0.76; repeated measurements: HR = 0.78, 95% CI 0.55–1.10, p-trend = 0.27). Results were the same when comparing PA level 9–10 to the reference level (baseline: HR = 0.80, 95% CI 0.56–1.12, p-trend = 0.76; repeated measurements: HR = 0.82, 95% CI 0.58–1.16, p-trend = 0.27). Similarly, we found no association between PA levels and the risk of rectal cancer.

Conclusions

Women may need to look beyond PA in order to reduce their risk of CRC.

Height and body fatness and colorectal cancer risk: an update of the WCRF-AICR systematic review of published prospective studies

PURPOSE

There is no published dose-response meta-analysis on the association between height and colorectal cancer risk (CRC) by sex and anatomical sub-site. We conducted a meta-analysis of prospective studies on the association between height and CRC risk with subgroup analysis and updated evidence on the association between body fatness and CRC risk.

METHODS

PubMed and several other databases were searched up to November 2016. A random effects model was used to calculate dose-response summary relative risks (RR's).

RESULTS

47 studies were included in the meta-analyses including 50,936 cases among 7,393,510 participants. The findings support the existing evidence regarding a positive association of height, general and abdominal body fatness and CRC risk. The summary RR were 1.04 [95% (CI)1.02-1.05, I² = 91%] per 5 cm increase in height, 1.02 [95% (CI)1.01-1.02, I² = 0%] per 5 kg increase in weight, 1.06 [95% (CI)1.04-1.07, I² = 83%] per 5 kg/m2 increase in BMI, 1.02 [95% (CI)1.02-1.03, I² = 4%] per 10 cm increase in waist circumference, 1.03 [95% (CI)1.01-1.05, I² = 16%] per 0.1 unit increase in waist to hip ratio. The significant association for height and CRC risk was similar in men and women. The significant association for BMI and CRC risk was stronger in men than in women.

CONCLUSION

The positive association between height and risk of CRC suggests that life factors during childhood and early adulthood might play a role in CRC aetiology. Higher general and abdominal body fatness during adulthood are risk factors of CRC and these associations are stronger in men than in women.

Association of physical activity and sitting time with incident colorectal cancer in postmenopausal women

Findings from epidemiological studies have found that physical activity (PA) is associated with a lower risk of colorectal cancer (CRC). Recent studies have found an increased CRC risk with higher sitting time (ST); however, many studies did not include PA as a potential confounder. The objective of this project was to investigate the independent and combined associations of ST and PA with the risk of incident CRC, specifically colon and rectal cancer. Participants in the Women's Health Initiative Observational Study (n=74 870), 50-79 years of age self-reported ST and PA at baseline, years 3 and 6. Incident CRC was the primary outcome; colon and rectal cancers were the secondary outcomes, which were centrally adjudicated. Over a 13-year follow-up period, 1145 incident cases of CRC were documented. A positive age-adjusted association was found between higher ST (≥10 vs. <5 h/day) and CRC (P for trend=0.04) and colon cancer (P for trend=0.05); however, these associations were attenuated and no longer significant in multivariable-adjusted models. Compared with inactive women (≤1.7 MET-h/week), the multivariable risk of CRC in the high PA (>20 MET-h/week) group was 0.81 (95% confidence interval: 0.66-1.00; P for trend 0.04). Compared with inactive women with high ST (≥10 h/day), there was a trend toward reduced multivariable CRC risks with higher PA irrespective of ST level (interaction=0.64). We observed an inverse association between leisure time PA and the risk of CRC, particularly for rectal cancer. There was no association between ST and CRC in multivariable models.

Physical activity, obesity and sedentary behaviour and the risks of colon and rectal cancers in the 45 and up study

Background

Obesity and physical activity (PA) are predictors of colon (CC) and rectal (RC) cancers. Prolonged sitting is also emerging as a potential predictor for these cancers. Little knowledge exists about the interactive effects of obesity, PA and prolonged sitting on cancer risk. This analysis assessed independent and interactive effects of PA, body mass index (BMI) and sitting time on CC and RC risks.

Methods

This analysis used data from a prospective study of 226,584 participants aged 45 years and over in New South Wales (NSW), Australia, who joined the 45 and Up study between 2006 and 2009. Baseline data were linked with data relating to mortality, cancer registration, hospital admission and Department of Human Services to December 2010. Multivariable Cox regression was used to estimate adjusted hazard ratios (referred to as relative risks, RRs) and 95% confidence intervals (Cis). Statistical significance was defined as p < 0.05.

Results

There were 846 and 369 ascertained cases of CC and RC. BMI was positively associated with CC risk (p = 0.003, P-trend = 0.0006) but not with RC. CC risk was increased in participants in the highest BMI quartile (≥29.4-≤50 kg/m²) compared to the lowest (15- < 23.6 kg/m²), (RR = 1.32, 95% CI:1.08–1.63). PA was associated with CC risk (p = 0.02) but not with RC. Specifically, CC risk was lower in individuals partaking in any amount of vigorous activity (time/week) compared to participants with no engagement (RR = 0.78, 95% CI:0.65–0.93). Sitting time was not associated with CC or RC. We found no evidence of interactive effects of PA, BMI and prolonged sitting on cancer risk.

Conclusion

This evidence suggests that a healthy weight and vigorous activity are essential to reduce CC risk since these factors may be independent of each other.

The Biased G-Protein-Coupled Receptor Agonism Bridges the Gap between the Insulin Receptor and the Metabolic Syndrome

Insulin signaling, as mediated through the insulin receptor (IR), plays a critical role in metabolism. Aberrations in this signaling cascade lead to several pathologies, the majority of which are classified under the umbrella term "metabolic syndrome". Although many of these pathologies are associated with insulin resistance, the exact mechanisms are not well understood. One area of current interest is the possibility of G-protein-coupled receptors (GPCRs) influencing or regulating IR signaling. This concept is particularly significant, because GPCRs have been shown to participate in cross-talk with the IR. More importantly, GPCR signaling has also been shown to preferentially regulate specific downstream signaling targets through GPCR agonist bias. A novel study recently demonstrated that this GPCR-biased agonism influences the activity of the IR without the presence of insulin. Although GPCR-IR cross-talk has previously been established, the notion that GPCRs can regulate the activation of the IR is particularly significant in relation to metabolic syndrome and other pathologies that develop as a result of alterations in IR signaling. As such, we aim to provide an overview of the physiological and pathophysiological roles of the IR within metabolic syndrome and its related pathologies, including cardiovascular health, gut microflora composition, gastrointestinal tract functioning, polycystic ovarian syndrome, pancreatic cancer, and neurodegenerative disorders. Furthermore, we propose that the GPCR-biased agonism may perhaps mediate some of the downstream signaling effects that further exacerbate these diseases for which the mechanisms are currently not well understood.

Women at war: The crucible of Vietnam

Relatively little has been written about the military women who served in Vietnam, and there is virtually no literature on deployed civilian women (non-military). We examined the experiences of 1285 American women, military and civilian, who served in Vietnam during the war and responded to a mail survey conducted approximately 25 years later in which they were asked to report and reflect upon their experiences and social and health histories.

We compare civilian women, primarily American Red Cross workers, to military women stratified by length of service, describe their demographic characteristics and warzone experiences (including working conditions, exposure to casualties and sexual harassment), and their homecoming following Vietnam. We assess current health and well-being and also compare the sample to age- and temporally-comparable women in the General Social Survey (GSS), with which our survey shared some measures.

Short-term (<10 years) military service women (28%) were more likely to report their Vietnam experience as “highly stressful” than were career (>20 years; 12%) and civilian women (13%). Additional differences regarding warzone experiences, homecoming support, and health outcomes were found among groups. All military and civilian women who served in Vietnam were less likely to have married or have had children than women from the general population, χ² (8) = 643.72, p < .001. Career military women were happier than women in the general population (48% were “very happy”, as compared to 38%). Civilian women who served in Vietnam reported better health than women in the other groups. Regression analyses indicated that long-term physical health was mainly influenced by demographic characteristics, and that mental health and PTSD symptoms were influenced by warzone and homecoming experiences. Overall, this paper provides insight into the experiences of the understudied women who served in Vietnam, and sheds light on subgroup differences within the sample.

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Physical health of women deployed to Vietnam was influenced by warzone experiences.

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Career military women Vietnam veterans are happier than women in general population.

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Military and non-military Vietnam service women less likely to marry or have kids.

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Paper provides insight to mostly unstudied lives of American women of Vietnam War.

Adiponectin, Leptin, IGF-1, and Tumor Necrosis Factor Alpha As Potential Serum Biomarkers for Non-Invasive Diagnosis of Colorectal Adenoma in African Americans

The potential role of adiponectin, leptin, IGF-1, and tumor necrosis factor alpha (TNF-α) as biomarkers in colorectal adenoma is not clear. Therefore, we aimed to investigate the blood serum levels of these biomarkers in colorectal adenoma. The case-control study consisted of serum from 180 African American patients with colon adenoma (cases) and 198 healthy African Americans (controls) at Howard University Hospital. We used ELISA for adiponectin, leptin, IGF-1, and TNF-α detection and quantification. Statistical analysis was performed by t-test and multivariate logistic regression. The respective differences in median leptin, adiponectin, IGF-1, and TNF-α levels between control and case groups (13.9 vs. 16.4), (11.3 vs. 46.0), (4.5 vs. 12.9), and (71.4 vs. 130.8) were statistically significant (P < 0.05). In a multivariate model, the odds ratio for adiponectin, TNF-α, and IGF-1 were 2.0 (95% CI = 1.6-2.5; P < 0.001), 1.5 (95% CI = 1.5(1.1-2.0); P = 0.004), and 1.6 (95% CI = 1.3-2.0; P < 0.001), respectively. There was a positive correlation between serum adiponectin and IGF-1 concentrations with age (r = 0.17, P < 0.001 and r = 0.13, P = 0.009), TNF-α, IGF-1, and leptin concentration with body mass index (BMI) (r = 0.44, P < 0.001; r = 0.11, P = 0.03; and r = 0.48, P < 0.001), respectively. Also, there was a negative correlation between adiponectin and leptin concentrations with BMI (r = -0.40, P < 0.001), respectively. These data support the hypothesis that adiponectin, IGF-1, and TNF-α high levels correlate with higher risk of colon adenoma and can thus be used for colorectal adenomas risk assessment.

Abdominal obesity and colorectal cancer risk: systematic review and meta-analysis of prospective studies

The association between abdominal obesity (as measured by waist circumference (WC) and waist-to-hip ratio (WHR)) and colorectal cancer (CRC) has not been fully quantified, and the magnitude of CRC risk associated with abdominal obesity is still unclear. A meta-analysis of prospective studies was performed to elucidate the CRC risk associated with abdominal obesity. Pubmed and Embase were searched for studies assessing the association between abdominal obesity and CRC risk. Relative risks (RRs) with 95% confidence intervals (95% CIs) were pooled using random-effects model of meta-analysis. Nineteen prospective cohort studies from eighteen publications were included in this meta-analysis. A total of 12,837 CRC cases were identified among 1,343,560 participants. Greater WC and WHR were significantly associated with increased risk of total colorectal cancer (WC: RR 1.42, 95% CI 1.30, 1.55; WHR: RR 1.39, 95% CI 1.25, 1.53), colon cancer (WC: RR 1.53, 95% CI 1.36, 1.72; WHR: 1.39, 95% CI 1.18, 1.63), and rectal cancer (WC: RR 1.20, 95% CI 1.03, 1.39; WHR: RR 1.22, 95% CI 1.05, 1.42). Subgroup analyses further identified the robustness of the association above. No obvious risk of publication bias was observed. In summary, abdominal obesity may play an important role in the development of CRC.

Obesity-related parameters and colorectal adenoma development

BACKGROUND

Obesity increases the risk of colorectal adenoma and colorectal cancer. However, the obesity-related parameters that are best for assessing the risk of colorectal adenoma development remain unclear. We analyzed the parameters that may best describe the association between obesity and colorectal adenoma development.

METHODS

In this retrospective cohort study, 3405 individuals underwent screening colonoscopy during routine health examinations. We measured body mass index; waist circumference; and metabolic parameters such as high-density lipoprotein-cholesterol, glucose, triglyceride, and systolic blood pressure. We analyzed the risk of developing colorectal adenoma, relative to obesity-related parameters, over a mean interval of 5.8 years from baseline colonoscopy.

RESULTS

In a multivariate analysis, waist circumference was the only obesity-related marker associated with an increased risk of metachronous colorectal adenoma. Men with waist circumferences ≥85 cm and women with waist circumference ≥82 cm had a 31% increased risk of metachronous colorectal adenoma compared to those with smaller waist circumferences [odds ratio (OR) 1.31; 95% confidence interval (CI, 1.09-1.57)]. Other factors associated with metachronous colorectal adenoma were age (OR, 1.03; 95% CI 1.02-1.04), male sex (OR 1.49; 95% CI 1.17-1.88), alcohol consumption ≥3/week (OR 1.33; 95% CI 1.10-1.62), the number of adenoma at baseline (OR 1.21; 95% CI 1.10-1.33), and the presence of advanced adenoma at baseline (OR 1.60; 95% CI 1.24-2.06).

CONCLUSIONS

Our findings suggest that central obesity, represented by waist circumference, is a significant predictor of metachronous colorectal adenoma, independent of body mass index and other metabolic variables.

Body fatness at an early age and risk of colorectal cancer

While there is convincing evidence that excess body fatness in adulthood is positively associated with colorectal cancer risk, the association between body fatness at an early age (≤30 years) and the risk of colorectal cancer has been equivocal. The present meta-analysis was performed to clarify this association. PubMed and Web of Science databases were searched for relevant studies that investigated this association. The risk estimates from each study were transformed into a continuous variable for each 5 kg/m² increase in body mass index (BMI). A random effects model was used to calculate the summary relative risks (RRs) with 95% confidence intervals (CIs). A total of 15 observational studies (13 cohort studies and two case-control studies) were included in this meta-analysis. Each 5 kg/m² increase in BMI was significantly associated with a 13% (RR 1.13, 95% CI 1.08, 1.19), 17% (RR 1.17, 95% CI 1.09, 1.25) and 8% (RR 1.08, 95% CI 1.04, 1.11) higher risk of colorectal cancer overall, in men, and in women, respectively. Substantial heterogeneity was observed across studies. Based on the anatomic subsite, each 5 kg/m² increase in BMI was significantly associated with a 14% (RR 1.14, 95% CI 1.07, 1.22) higher risk of colon cancer, whereas no association (RR 1.03, 95% CI 0.95, 1.13) was observed with rectal cancer. In summary, body fatness at an early age may affect colon cancer risk later in life. Prevention of overweight and obesity in young individuals should be emphasized to prevent early-onset colon cancer attributed to excess body fatness.

Obesity-associated digestive cancers: A review of mechanisms and interventions

The prevalence of obesity has steadily increased over the past few decades. Previous studies suggest that obesity is an oncogenic factor and that over 20% of all cancers are obesity-related. Among such cancers, digestive system malignancies (including esophageal adenocarcinomas, colorectal cancers, and cancers of the gastric cardia, liver, and pancreas) are reported most frequently. While the 5-year survival rates of cancers of the breast and prostate are 90%, that rate is only 45% for digestive cancers. In this review, the mechanisms of obesity-associated digestive cancers are discussed, with an emphasis on obesity-related gene mutations, insulin and insulin-like growth factor signaling pathways, chronic inflammation, and altered adipokine levels. Evidence that these factors often function interdependently rather than independently in carcinogenesis is presented. Recommended interventions that may reduce the burden of obesity-associated digestive cancers, such as participation in physical activity, diet modulation, and calorie restriction, are also described.

Exploring the Linkage between Activity-Friendly Zoning, Inactivity, and Cancer Incidence in the United States

Background: Physical activity (PA) protects against cancer and enhances cancer survivorship. Given high inactivity rates nationwide, population-level physical activity facilitators are needed. Several authoritative bodies have recognized that zoning and planning helps create activity-friendly environments. This study examined the association between activity-friendly zoning, inactivity, and cancer in 478 of the most populous U.S. counties.Methods: County geocodes linked county-level data: cancer incidence and smoking (State Cancer Profiles), inactivity (Behavioral Risk Factor Surveillance System), 11 zoning measures (compiled by the study team), and covariates (from the American Community Survey and NAVTEQ). For each zoning measure, single mediation regression models and Sobel tests examined whether activity-friendly zoning was associated with reduced cancer incidence, and whether inactivity mediated those associations. All models were clustered on state with robust SEs and significance at the P < 0.05 level.Results: Zoning for crosswalks, bike-pedestrian connectivity, and bike-pedestrian trails/paths were associated with reduced cancer incidence (β between -0.71 and -1.27, P < 0.05), about 1 case per 100,000 for each 10 percentage-point increase in county population exposure to zoning. Except for crosswalks, each association was mediated by inactivity. However, county smoking attenuated these results, with only crosswalks remaining significant. Results were similar for males (with zoning for bike-pedestrian connectivity, street connectivity, and bike-pedestrian trails/paths), but not females, alone.Conclusions: Zoning can help to create activity-friendly environments that support decreased inactivity, and possibly reduced cancer incidence.Impact: Given low physical activity levels nationwide, cross-sectoral collaborations with urban planning can inform cancer prevention and public health efforts to decrease inactivity and cancer. Cancer Epidemiol Biomarkers Prev; 26(4); 578-86. ©2017 AACRSee all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences."

Predictive and prognostic biomarkers in colorectal cancer: A systematic review of recent advances and challenges

BACKGROUND

Colorectal cancer (CRC) is one of the leading cause of cancer deaths worldwide. Since CRC is largely asymptomatic until alarm features develop to advanced stages, the implementation of the screening programme is very much essential to reduce cancer incidence and mortality rates. CRC occurs predominantly from accumulation of genetic and epigenetic changes in colon epithelial cells, which later gets transformed into adenocarcinomas.

SCOPE OF REVIEW

The current challenges of screening paradigm and diagnostic ranges are from semi-invasive methods like colonoscopy to non-invasive stool-based test, have resulted in over-diagnosis and over-treatment of CRC. Hence, new screening initiatives and deep studies are required for early diagnosis of CRC. In this regard, we not only summarise current predictive and prognostic biomarkers with their potential for diagnostic and therapeutic applications, but also describe current limitations, future perspectives and challenges associated with the progression of CRC.

MAJOR CONCLUSIONS

Currently many potential biomarkers have already been successfully translated into clinical practice eg. Fecal haemoglobin, Carcinoembryonic antigen (CEA) and CA19.9, although these are not highly promising diagnostic target for personalized medicine. So there is a critical need for reliable, minimally invasive, highly sensitive and specific genetic markers of an individualised and optimised patient treatment at the earliest disease stage possible.

GENERAL SIGNIFICANCE

Identification of a new biomarker, or a set of biomarkers to the development of a valid, and clinical sensible assay that can be served as an alternative tool for early diagnosis of CRC and open up promising new targets in therapeutic intervention strategies.

Physical activity and the incidence of multiple sclerosis

OBJECTIVE

To study whether physical activity during adulthood or early life is associated with multiple sclerosis (MS) incidence in 2 prospective cohorts of women.

METHODS

Women in the Nurses' Health Study (NHS) (n = 81,723; 1986-2004) and NHS II (n = 111,804; 1989-2009) reported recent physical activity at baseline and in selected follow-up questionnaires. Using this information, we calculated total metabolic equivalent hours of physical activity per week, a measure of energy expenditure. There were 341 confirmed MS cases with first symptoms after baseline. Participants also reported early-life activity. To estimate relative rates (RRs) and 95% confidence intervals (CIs), we used Cox proportional hazards models, adjusting for age, latitude of residence at age 15, ethnicity, smoking, supplemental vitamin D, and body mass index at age 18.

RESULTS

Compared with women in the lowest baseline physical activity quartile, women in the highest quartile had a 27% reduced rate of MS (RR_pooled = 0.73, 95% CI 0.55-0.98; p-trend 0.08); this trend was not present in 6-year lagged analyses. Change in physical activity analyses suggested that women reduced activity before onset of MS symptoms. In NHS and NHS II, higher strenuous activity at ages 18-22 years was weakly associated with a decreased MS rate. However, in NHS II, total early-life activity at ages 12-22 was not associated with MS.

CONCLUSIONS

Though higher physical activity at baseline was weakly associated with lower MS risk, this may have been due to women reducing physical activity in response to subclinical MS.

Is obesity an advantage in patients with colorectal cancer?

Obesity/higher BMI appears to be important determinants in the development of colon cancer as well as in predicting outcomes in the adjuvant setting in these patients. These associations seem to be stronger for men and tend to be 'J-shaped', with worse outcomes in both lower and upper BMI categories than in the middle categories. How this factors in the metastatic setting is less clear. A recent pooled analysis of patients with metastatic colorectal cancer receiving bevacizumab in the first-line setting observed that patients with the lowest BMI had the lowest median overall survival. An incremental BMI increase of 5 kg/m(2) led to actually a decrease in the risk of death (hazard ratio, 0.911 [95% CI, 0.879-0.944]). The observed association does not necessarily mean that obesity is an advantage for patients with metastatic colorectal cancer. More likely, it is conceivable that, in patients with metastatic colorectal cancer with a lower BMI, the effects of cancer-related cachexia may be more deleterious than the potential adverse events related to a higher BMI. In patients already diagnosed with metastatic disease, studying how body weight affects tumor biology and treatment-related decisions are important considerations.

Colorectal Cancer Epidemiology in the Nurses' Health Study

OBJECTIVES

To review the contribution of the Nurses' Health Study (NHS) to identifying risk and protective factors for colorectal adenomas and colorectal cancer (CRC).

METHODS

We performed a narrative review of the publications using the NHS between 1976 and 2016.

RESULTS

Existing epidemiological studies using the NHS have reported that red and processed meat, alcohol, smoking, and obesity were associated with an increased risk of CRC, whereas folate, calcium, vitamin D, aspirin, and physical activity were associated with decreased risk of CRC. Moreover, modifiable factors, such as physical activity, vitamin D, folate, insulin and insulin-like growth factor binding protein-1, and diet quality, were identified to be associated with survival among CRC patients. In recent years, molecular pathological epidemiological studies have been actively conducted and have shown refined results by molecular subtypes of CRC.

CONCLUSIONS

The NHS has provided new insights into colorectal adenomas, CRC etiology, and pathogenic mechanisms. With its unique strengths, the NHS should continue to contribute to the field of CRC epidemiology and play a major role in public health.

A Cost-Benefit Analysis of Physical Activity Using Bike/Pedestrian Trails

From a public health perspective, a cost-benefit analysis of using bike/pedestrian trails in Lincoln, Nebraska, to reduce health care costs associated with inactivity was conducted. Data was obtained from the city's 1998 Recreational Trails Census Report and the literature. Per capita annual cost of using the trails was U.S.$209.28 ($59.28 construction and maintenance, $150 of equipment and travel). Per capita annual direct medical benefit of using the trails was $564.41. The cost-benefit ratio was 2.94, which means that every $1 investment in trails for physical activity led to $2.94 in direct medical benefit. The sensitivity analyses indicated the ratios ranged from 1.65 to 13.40. Therefore, building trails is cost beneficial from a public health perspective. The most sensitive parameter affecting the cost-benefit ratios were equipment and travel costs; however, even for the highest cost, every $1 investment in trails resulted in a greater return in direct medical benefit.

Metastatic Colorectal Cancer in Hispanics: Treatment Outcomes in a Treated Population

BACKGROUND

In United States Hispanics have disparities in the presentation and outcome of colorectal cancer (CRC) largely attributed to their late presentation and lower socioeconomic status. Impact of treatment, especially in the metastatic setting, in the observed outcome is an unexplored area. We explored the role of treatment in the outcome of metastatic CRC we performed a retrospective analysis to assess the contribution of demographics, tumor characteristics, and health care setting on survival differences.

PATIENTS AND METHODS

We conducted a retrospective study of patients who were treated with metastatic CRC at Los Angeles County Hospital-University of Southern California (LAC-USC, a public hospital) and Norris Comprehensive Cancer Center (NCCC, private hospital) between 2002 and 2012. Both these institutions are staffed by the same providers and therefore treatment algorithms and access to drugs were similar. We identified metastatic CRC patients who received chemotherapy from administrative records. Demographics, tumor, and treatment related factors were collected. The primary end point was time to progression (TTP: time from the first day of chemotherapy to the date of progression). Overall survival (OS) was measured from the first day of chemotherapy to death or last follow-up. Descriptive statistics were used to describe the population and chi-square, Wilcoxon, and log-rank tests were used for comparison between the groups.

RESULTS

A total of 242 patients, 44% Hispanic, 26% non-Hispanic whites (NHWs), 21% Asian and 9% black were included. Median TTP was 9.2 months (95% confidence interval [CI], 7.6-11.6) in Hispanics, and 20.7 months (95% CI, 9.6-27.5; P < .05) in NHWs. Median OS in Hispanics was 16.3 months (95% CI, 13.3-18.5), and in NHWs was 33.5 months (95% CI, 22.1-63.6; P < .001). Hispanics who were treated at LAC-USC had longer TTP in comparison to Hispanics at NCCC (P = .04).

CONCLUSION

Hispanics with metastatic CRC have shorter TTP and OS on first line therapy when adjusted for health care setting, demographics, disease characteristics, and treatment factors.

CT-based compartmental quantification of adipose tissue versus body metrics in colorectal cancer patients

PURPOSE

While obesity is considered a prognostic factor in colorectal cancer (CRC), there is increasing evidence that not simply body mass index (BMI) alone but specifically abdominal fat distribution is what matters. As part of the ColoCare study, this study measured the distribution of adipose tissue compartments in CRC patients and aimed to identify the body metric that best correlates with these measurements as a useful proxy for adipose tissue distribution.

MATERIALS AND METHODS

In 120 newly-diagnosed CRC patients who underwent multidetector computed tomography (CT), densitometric quantification of total (TFA), visceral (VFA), intraperitoneal (IFA), retroperitoneal (RFA), and subcutaneous fat area (SFA), as well as the M. erector spinae and psoas was performed to test the association with gender, age, tumor stage, metabolic equivalents, BMI, waist-to-height (WHtR) and waist-to-hip ratio (WHR).

RESULTS

VFA was 28.8 % higher in men (p_VFA<0.0001) and 30.5 % higher in patients older than 61 years (p_VFA<0.0001). WHtR correlated best with all adipose tissue compartments (r_VFA=0.69, r_TFA=0.84, p<0.0001) and visceral-to-subcutaneous-fat-ratio (VFR, r_VFR=0.22, p=<0.05). Patients with tumor stages III/IV showed significantly lower overall adipose tissue than I/II. Increased M. erector spinae mass was inversely correlated with all compartments.

CONCLUSION

Densitometric quantification on CT is a highly reproducible and reliable method to show fat distribution across adipose tissue compartments. This distribution might be best reflected by WHtR, rather than by BMI or WHR.

KEY POINTS

• Densitometric quantification of adipose tissue on CT is highly reproducible and reliable. • Waist-to-height ratio better correlates with adipose tissue compartments and VFR than BMI or waist-to-hip ratio. • Men have higher a higher visceral fat area than women. • Patients older than 61 years have higher visceral fat area. • Patients with tumor stages III/IV have significantly lower adipose tissue than those in stages I/II.

American Cancer Society Colorectal Cancer Survivorship Care Guidelines

Colorectal cancer (CRC) is the third most common cancer and third leading cause of cancer death in both men and women and second leading cause of cancer death when men and women are combined in the United States (US). Almost two-thirds of CRC survivors are living 5 years after diagnosis. Considering the recent decline in both incidence and mortality, the prevalence of CRC survivors is likely to increase dramatically over the coming decades with the increase in rates of CRC screening, further advances in early detection and treatment and the aging and growth of the US population. Survivors are at risk for a CRC recurrence, a new primary CRC, other cancers, as well as both short-term and long-term adverse effects of the CRC and the modalities used to treat it. CRC survivors may also have psychological, reproductive, genetic, social, and employment concerns after treatment. Communication and coordination of care between the treating oncologist and the primary care clinician is critical to effectively and efficiently manage the long-term care of CRC survivors. The guidelines in this article are intended to assist primary care clinicians in delivering risk-based health care for CRC survivors who have completed active therapy.

Long-term status and change of body fat distribution, and risk of colorectal cancer: a prospective cohort study

BACKGROUND

Although obesity has been linked to an increased risk of colorectal cancer (CRC), the risk associated with long-term status or change of body fat distribution has not been fully elucidated.

METHODS

Using repeated anthropometric assessments in the Nurses' Health Study and Health Professionals Follow-up Study, we prospectively investigated cumulative average waist circumference, hip circumference and waist-to-hip ratio, as well as their 10-year changes over adulthood, in relation to CRC risk over 23-24 years of follow-up. Cox proportional hazards models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

High waist circumference, hip circumference and waist-to-hip ratio were all associated with a higher CRC risk in men, even after adjusting for body mass index. The association was attenuated to null in women after adjusting for body mass index. Ten-year gain of waist circumference was positively associated with CRC risk in men (P for trend = 0.03), but not in women (P for trend = 0.34).Compared with men maintaining their waist circumference, those gaining waist circumference by ≥ 10 cm were at a higher risk of CRC, with a multivariable-adjusted HR of 1.59 (95% CI, 1.01-2.49). This association appeared to be independent of weight change.

CONCLUSIONS

Abdominal adiposity, independent of overall obesity, is associated with an increased CRC risk in men but not in women. Our findings also provide the first prospective evidence that waist circumference gain during adulthood may be associated with higher CRC risk in men, thus highlighting the importance of maintaining a healthy waist for CRC prevention.

Body weight gain and risk of colorectal cancer: a systematic review and meta-analysis of observational studies

While the relationship between body mass index as an indicator of excess body weight and the risk of colorectal cancer (CRC) is well established, the association between body weight gain in adulthood and risk of CRC remains unresolved. We quantified this association in a meta-analysis of 12 observational studies published until November 2014 with a total of 16,151 incident CRC cases. Random effect models were used to obtain summary relative risks (RR) and 95% confidence intervals (95% CIs). Between-study heterogeneity was assessed using I(2) statistics. Overall, the summary RR (95% CI) was 1.22 (1.14-1.30) for high body weight gain (midpoint: 15.2 kg) compared with stable weight (P for heterogeneity = 0.182; I(2) = 21.2%). In a dose-response analysis, each 5 kg weight gain was associated with a 4% (95% CI: 2%-5%) higher risk of CRC. The association persisted after adjustment for body weight at younger age and was present for both men and women, as well as for colon and rectal cancer. Differences by sex were detected for colon cancer (P for interaction = 0.003, with higher risk for men than women), but not for rectal cancer (P for interaction = 0.613). In conclusion, these data underscore the importance of body weight management from early adulthood onwards for the prevention of CRC development.

Proportion of colon cancer attributable to lifestyle in a cohort of US women

BACKGROUND

Many modifiable lifestyle factors have been associated with colon cancer risk, but less is known about their effect on disease when considered together. Estimating the proportion of colon cancer cases that could be prevented by the adoption of combined modifiable lifestyle behaviors will provide important insights into disease prevention.

METHODS

In the Nurses' Health Study, we defined a low-risk group according to a combination of six factors: body mass index < 25 kg/m(2), physical activity of ≥ 21 metabolic equivalent of task per week, alcohol consumption ≤ 30 g/day, cigarette smoking <10 pack-years before the age of 30, current use of multivitamins for ≥ 15 years, and total calcium intake ≥ 700 mg/day. A composite risk score index was created and the population attributable risk (PAR%) was calculated after accounting for other known risk or protective factors.

RESULTS

We documented 1,127 colon cancer cases among 81,092 over 24 years of follow-up. Compared with women in the lowest risk category, the women at all other exposure levels had a hazard ratio of colon cancer of 1.81 (95% confidence interval 1.15-2.85). The score index was significantly and linearly related to an increasing risk of colon cancer (p value for trend <0.0001). The PAR% of the six risk factors considered together in relation to colon cancer was 0.37 (95% CI 0.09-0.60). When regular aspirin use (two tablets/week for six or more years) was included with the other low-risk behaviors, the PAR% increased to 0.43 (95% CI 0.14-0.65).

CONCLUSIONS

Beyond the known benefit from colonoscopy/sigmoidoscopy, key behavior modifications and adherence to a healthy lifestyle could avoid approximately 37% of colon cancer cases among women.

Fetal growth and subsequent maternal risk of colorectal cancer

BACKGROUND

High birth weight has been associated with subsequent increased risk of breast cancer in the infant's mother, possibly related to maternal estrogen and growth factor pathways. However, its association with maternal risk of colorectal cancer, the third most common cancer among women, is unknown.

METHODS

We conducted a national cohort study of 1,838,509 mothers who delivered 3,590,523 babies in Sweden in 1973-2008, followed up for colorectal cancer incidence through 2009.

RESULTS

There were 7,318 mothers diagnosed with colorectal cancer in 36.8 million person-years of follow-up. After adjusting for maternal age, body mass index, diabetes, and other potential confounders, high fetal growth was associated with a subsequent increased risk of colorectal cancer in the mother [incidence rate ratio (IRR) per additional 1 SD relative to mean birth weight for gestational age and sex, 1.05; 95% confidence intervals (CI), 1.03-1.07; P < 0.0001]. Each 1,000 g increase in the infant's birth weight was associated with a 12% increase in the mother's subsequent risk of colorectal cancer (IRR, 1.12; 95% CI, 1.07-1.17; P < 0.0001). Multiple gestation was also independently associated with increased maternal risk of colorectal cancer (IRR for twin or higher order vs. singleton, 1.22; 95% CI, 1.04-1.44; P = 0.02).

CONCLUSION

In this large cohort study, high fetal growth and multiple gestation were independently associated with subsequent higher maternal risk of colorectal cancer. These findings warrant further investigation of maternal growth factor and estrogen pathways in the etiology of colorectal cancer.

IMPACT

If confirmed, our findings may help identify subgroups of women at high risk of colorectal cancer.

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.

Early life body fatness and risk of colorectal cancer in u.s. Women and men-results from two large cohort studies

BACKGROUND

The association between body fatness before adulthood and later risk of colorectal cancer remains unclear. We hypothesized that, independent of adult body fatness, early life body fatness would be associated with a higher risk of developing colorectal cancer.

METHODS

We assessed body fatness during childhood and adolescence using a validated 9-level somatotype and inquired body weight in young adulthood in the Nurses' Health Study and Health Professionals Follow-up Study. We used the Cox proportional hazard regression modeling to estimate relative risks [RR, 95% confidence intervals (CI)] adjusting for adult body mass index (BMI) and other known colorectal cancer risk factors.

RESULTS

We identified 2,100 incident colorectal cancer cases (1,292 in women and 808 in men) during 22 years of follow-up. Among women, the RR (95% CI) for childhood body fatness of level 5 or higher versus level 1 was 1.28 (1.04-1.58; Ptrend = 0.08) and for adolescent body fatness, it was 1.27 (1.01-1.60; Ptrend = 0.23). The corresponding RRs for men were 1.04 (0.82-1.31; Ptrend = 0.48) and 0.98 (0.75-1.27; Ptrend = 0.20), respectively. Results were generally similar across anatomic subsites within the colorectum. In addition, the RRs comparing BMI categories ≥27.5 to <19 kg/m(2) were 1.44 (1.06-1.95, at age 18; Ptrend = 0.009) for women and 1.18 (0.84-1.65, at age 21; Ptrend = 0.57) for men.

CONCLUSION

Increased body fatness in early life, independent of adult obesity, might be a risk factor for colorectal cancer in women, but we observed a weaker association in men.

IMPACT

Our findings support the growing evidence that early life body fatness affects the risk of colorectal cancer many decades later.

Adult weight gain and adiposity-related cancers: a dose-response meta-analysis of prospective observational studies

BACKGROUND

Adiposity, measured by body mass index, is implicated in carcinogenesis. While adult weight gain has diverse advantages over body mass index in measuring adiposity, systematic reviews on adult weight gain in relation to adiposity-related cancers are lacking.

METHODS

PubMed and Embase were searched through September 2014 for prospective observational studies investigating the relationship between adult weight gain and the risk of 10 adiposity-related cancers. Dose-response meta-analyses were performed using a random-effects model to estimate summary relative risk (RR) and 95% confidence interval (CI) for each cancer type. All statistical tests were two-sided.

RESULTS

A total of 50 studies were included. For each 5 kg increase in adult weight gain, the summary relative risk was 1.11 (95% CI = 1.08 to 1.13) for postmenopausal breast cancer among no- or low-hormone replacement therapy (HRT) users, 1.39 (95% CI = 1.29 to 1.49) and 1.09 (95% CI = 1.02 to 1.16) for postmenopausal endometrial cancer among HRT nonusers and users, respectively, 1.13 (95% CI = 1.03 to 1.23) for postmenopausal ovarian cancer among no or low HRT users, 1.09 (95% CI = 1.04 to 1.13) for colon cancer in men. The relative risk of kidney cancer comparing highest and lowest level of adult weight gain was 1.42 (95% CI = 1.11 to 1.81). Adult weight gain was unrelated to cancers of the breast (premenopausal women, postmenopausal HRT users), prostate, colon (women), pancreas, and thyroid. An increase in risk associated with adult weight gain for breast cancer was statistically significantly greater among postmenopausal women (P(heterogeneity) = .001) and HRT nonusers (P(heterogeneity) = .001); that for endometrial cancer was alike among HRT nonusers (P(heterogeneity) = .04).

CONCLUSIONS

Avoiding adult weight gain itself may confer protection against certain types of cancers, particularly among HRT nonusers.