The insulin-like growth factor axis: A biological mechanism linking physical activity to colorectal cancer survival

Post-diagnosis physical activity and sedentary behaviour and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

Low physical activity and high sedentary behaviour have been clearly linked with colorectal cancer development, yet data on their potential role in colorectal cancer survival is limited. Better characterisation of these relationships is needed for the development of post-diagnosis physical activity and sedentary behaviour guidance for colorectal cancer survivors. We searched PubMed and Embase through 28 February 2022 for studies assessing post-diagnosis physical activity, and/or sedentary behaviour in relation to all-cause and cause-specific mortality and recurrence after colorectal cancer diagnosis. Total and recreational physical activity were assessed overall and by frequency, duration, intensity, and volume using categorical, linear, and non-linear dose-response random-effects meta-analyses. The Global Cancer Update Programme (CUP Global) independent Expert Committee on Cancer Survivorship and Expert Panel interpreted and graded the likelihood of causality. We identified 16 observational studies on 82,220 non-overlapping patients from six countries. Physical activity was consistently inversely associated with colorectal cancer morbidity and mortality outcomes, with 13%-60% estimated reductions in risk. Sedentary behaviour was positively associated with all-cause mortality. The evidence had methodological limitations including potential confounding, selection bias and reverse causation, coupled with a limited number of studies for most associations. The CUP Global Expert panel concluded limited-suggestive evidence for recreational physical activity with all-cause mortality and cancer recurrence. Total physical activity and its specific domains and dimensions, and sedentary behaviour were all graded as limited-no conclusion for all outcomes. Future research should focus on randomised trials, while observational studies should obtain objective and repeated physical activity measures and better adjustment for confounders.

Exercise and colorectal cancer: prevention and molecular mechanisms

Exercise and physical activity have been shown to be strongly associated with a decreased incidence rate of various chronic diseases especially numerous human malignancies. A huge number of clinical trials and meta-analysis have demonstrated that exercise is significantly effective in lowering the risk of colorectal cancer. In addition, it is suggested as an effective therapeutic modality against this cancer type. Therefore, in this review, we will review comprehensibly the effects of exercise in preventing, treating, and alleviating the adverse effects of conventional therapeutic options in colorectal cancer. Moreover, the possible mechanisms underlying the positive effects of exercise and physical activity in colorectal cancer, including regulation of inflammation, apoptosis, growth factor axis, immunity, epigenetic, etc. will be also discussed.

Exercise is an effective post-treatment management program in colorectal cancer survivals

Exercise improves muscle strength, cardiorespiratory fitness, emotional distress, physical activity, fatigue, and sleep quality in colorectal patients undergoing chemotherapy

Targeting and modulating insulin-like growth factor (IGF) system, inflammation, apoptosis, immunity, epigenetic, Leptin and Ghrelin, and signaling pathways are major underlying mechanisms for preventive effects of exercise in colorectal cancer

New perspective of ceria nanodots for precise tumor therapy via oxidative stress pathway

Ceria-based nanomaterials have aroused major attentions among the biomedical application research field in recent years. Most of the researches have mainly focused on promoting the functional healing therapies of normal cells/organs with cerium oxide compounds, while the applications of ceria-based materials employed on cancer curing processes have been merely mentioned. To explore the possible capabilities of cerium oxide nanomaterials exterminating tumor cells, innovatively, we synthesized the eco-friendly pure cerium oxide nanodots (CNDs), proving the prominent ability of CNDs used in tumor chemotherapy (CDT) via Fenton reaction with the highly presence of H2O2 (acidic pH) in tumor tissues. CNDs reacted with the self-produced H2O2 of tumor cells, which generated piled up toxic hydroxyl radical (·OH). The accumulated virulent ·OH restrained the growth of cancer cells intensively. This peroxidase-like activity, provided a distinguished paradigm for effective cancer curing treatment. We also verified the biosafety of CNDs applied on normal cells. Notably, not only did CNDs be harmless to normal cells, but also it protected them from the damages of reactive oxygen species (ROS). In normal cells/tissues, under the microenvironment of neutral pH and low level of H2O2, the CNDs could effectively function as an annihilator inhibiting ROS. They reduced the damages caused by ROS, exhibiting catalase-like activity. The research we studied, which estimated CNDs thoroughly, has provided a new perspective to the future researches of the cerium oxide biomaterial applications.

Linking insulin like growth factor-1 (IGF-1) rs6214 gene polymorphism and its serum level with risk of colorectal cancer

Background

Colorectal Cancer is found one of the most profound type of cancer around globe, affecting men and women with different ethnic and racial groups. Insulin-like growth factor 1 is known as peptide growth factor found to increase the proliferation of cell and prevent apoptosis. Insulin pathway might have linked with progression of colorectal cancer.

Methods

This study conducted on total 160 subjects, including 80 patients with colorectal cancer with 80 age and gender match controls. Clinical parameters were compared between the control group and Colorectal cancer group. Blood serum IGF-1 was quantified by using ELISA and IGF-1 rs6214(C/T) variations were investigated using TaqMan allelic discrimination assay.

Results

Blood serum level of Insulin growth factor-I (ng/ml) showed substantial association concerning groups while IGF-1 rs6214(C/T) genotype distribution observed increased in colorectal cancer patients as compared to controls with significant association. The variant TT and CT genotype frequency observed more common in cases as compared to control. However, the wild type CC genotype were common in cases used to compared with controls. The Odds Ratio reveal the risk of variant IGF-1 rs6214 T allele to increase 3 times compared to wild type allele.

Conclusion

The homozygous TT genotypes and T variant allele of IGF-1 rs6214(C/T) showed association with high serum Insulin growth factor level 1, may increase susceptibility to the colorectal cancer. This work will use to investigate the associations between Insulin-like growth factor 1 and rs6214(C/T) gene variant and blood serum level with the vulnerability to treat Colorectal. In summary, we have investigated the relationship between Insulin growth factor level hormone and colorectal cancer. Further studies are required to understand the association between colorectal cancer and polymorphism. However, this study can be serve as an informative study to uncover mechanisms behind main cause of colon cancer. Therefore, the genomic profiling of Insulin-like growth factor-1 can be helpful to treat colorectal cancer patients.

Role of physical exercise in modulating the insulin-like growth factor system for improving breast cancer outcomes: A meta-analysis

BACKGROUND

Physical activity prevents cancer and improves cancer outcomes. Insulin-like growth factor (IGF) signaling plays a significant role in cancer development and progression. However, there are heterogeneous results regarding physical activity and its effect on the IGF system. This study meta-analyzed the results of randomized clinical trials which evaluated the effects of physical exercise on the changes of physiologic markers to identify the role of physical exercise in modulating the IGF system in women with breast cancer.

METHODS

PubMed, Embase, CENTRAL, and SPORTDiscus were systematically searched until October 2020. Eligibility criteria included randomized controlled trials that evaluated the effects of physical exercise on the insulin-like growth factor system among women with breast cancer.

RESULTS

Twelve randomized controlled studies involving 736 participants were analyzed. Physical exercise significantly reduced levels of serum insulin (MD -1.24 μIU/mL, 95% CI -2.12 to -0.36, p = 0.006), IGF-II (MD -54.21 ng/mL, 95% CI -61.41 to -47.00, p < 0.00001), IGFBP-1 (MD -2.90 ng/mL, 95% CI -3.91 to -1.90, p < 0.00001), and HOMA score (MD -0.47, 95% CI -0.87 to -0.06, p = 0.02). In addition, serum glucose (MD -0.71 mg/dL, 95% CI -2.57 to 1.15; p = 0.45) and IGF-I levels (MD -5.23 ng/mL, 95% CI -13.00 to 2.53; p = 0.19) were decreased after physical exercise although they did not show a statistical significance.

CONCLUSION

Physical exercise had a positive effect on the IGF system in women with breast cancer.

Insulin-Like Growth Factor 1 (IGF-1) Signaling in Glucose Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common aggressive carcinoma types worldwide, characterized by unfavorable curative effect and poor prognosis. Epidemiological data re-vealed that CRC risk is increased in patients with metabolic syndrome (MetS) and its serum components (e.g., hyperglycemia). High glycemic index diets, which chronically raise post-prandial blood glucose, may at least in part increase colon cancer risk via the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway. However, the underlying mechanisms linking IGF-1 and MetS are still poorly understood. Hyperactivated glucose uptake and aerobic glycolysis (the Warburg effect) are considered as a one of six hallmarks of cancer, including CRC. However, the role of insulin/IGF-1 signaling during the acquisition of the Warburg metabolic phenotypes by CRC cells is still poorly understood. It most likely results from the interaction of multiple processes, directly or indirectly regulated by IGF-1, such as activation of PI3K/Akt/mTORC, and Raf/MAPK signaling pathways, activation of glucose transporters (e.g., GLUT1), activation of key glycolytic enzymes (e.g., LDHA, LDH5, HK II, and PFKFB3), aberrant expression of the oncogenes (e.g., MYC, and KRAS) and/or overexpression of signaling proteins (e.g., HIF-1, TGF-β1, PI3K, ERK, Akt, and mTOR). This review describes the role of IGF-1 in glucose metabolism in physiology and colorectal carcinogenesis, including the role of the insulin/IGF system in the Warburg effect. Furthermore, current therapeutic strategies aimed at repairing impaired glucose metabolism in CRC are indicated.

Colorectal Cancer Risk Following Bariatric Surgery in a Nationwide Study of French Individuals With Obesity

Importance

Although bariatric surgery is effective against morbid obesity, the association of this surgery with the risk of colorectal cancer remains controversial.

Objective

To assess whether bariatric surgery is associated with altered risk of colorectal cancer among individuals with obesity.

Design, Setting, and Participants

This retrospective, population-based, multicenter, cohort study based on French electronic health data included 1 045 348 individuals with obesity, aged 50 to 75 years, and free of colorectal cancer at baseline. All inpatients with obesity having data recorded during a hospital stay between 2009 and 2018 by the French national health insurance information system database were followed up for a mean (SD) of 5.3 (2.1) years for those who did not undergo bariatric surgery and 5.7 (2.2) years for those who underwent bariatric surgery. Two groups of patients comparable in terms of age, sex, body mass index, follow-up, comorbidities, and conditions who did or did not undergo surgery were also obtained by propensity score matching.

Exposures

Bariatric surgery (n = 74 131), including adjustable gastric banding, sleeve gastrectomy, gastric bypass; or no bariatric surgery (n = 971 217).

Main Outcomes and Measures

Primary outcome was incident colorectal cancer. Standardized incidence ratios were calculated using age-, sex-, and calendar year-matched colorectal cancer incidence among the general French population during the corresponding years. Secondary outcome was incident colorectal benign polyps.

Results

Among a total of 1 045 348 patients, the mean (SD) age was 57.3 (5.5) years for the 74 131 patients in the surgical cohort vs 63.4 (7.0) years for the 971 217 patients in the nonsurgical cohort. The mean (SD) follow-up was 6.2 (2.1) years for patients who underwent adjustable gastric banding, 5.5 (2.1) years for patients who underwent sleeve gastrectomy, and 5.7 (2.2) years for patients who underwent gastric bypass. In total, 13 052 incident colorectal cancers (1.2%) and 63 649 colorectal benign polyps were diagnosed. The rate of colorectal cancer was 0.6% in the bariatric surgery cohort and 1.3% in the cohort without bariatric surgery. In the latter cohort, 9417 cases were expected vs 12 629 observed, a standardized incidence ratio of 1.34 (95% CI, 1.32-1.36). In the bariatric surgery cohort, 428 cases were expected and 423 observed, a standardized incidence ratio of 1.0 (95% CI, 0.90-1.09). Propensity score-matched hazard ratios in comparable operated vs nonoperated groups were 0.68 (95% CI, 0.60-0.77) for colorectal cancer and 0.56 (95% CI, 0.53-0.59) for colorectal benign polyp. There were fewer new diagnoses of colorectal cancer after gastric bypass (123 of 22 343 [0.5%]) and sleeve gastrectomy (185 of 35 328 [0.5%]) than after adjustable gastric banding (115 of 16 460 [0.7%]), and more colorectal benign polyps after adjustable gastric banding (775 of 15 647 [5.0%]) than after gastric bypass (639 of 20 863 [3.1%]) or sleeve gastrectomy (1005 of 32 680 [3.1%]).

Conclusion and Relevance

The results of this nationwide cohort study suggested that following bariatric surgery, patients with obesity share the same risk of colorectal cancer as the general population, whereas for patients with obesity who do not undergo bariatric surgery, the risk is 34% above that of the general population.

What is the gut feeling telling us about physical activity in colorectal carcinogenesis?

In the last decades, more efforts are focused on the prevention and treatment of malignant diseases, given the increase in all cancers incidence A lifestyle change, including healthy eating habits and regular physical activity, has significantly impacted colorectal cancer prevention. The effect of dose-dependent physical activity on mortality and recurrence rates of colorectal carcinoma has been unequivocally demonstrated in observational studies. However, clear recommendations are not available on the frequency, duration, and intensity of exercise in patients with colorectal cancer due to the lack of evidence in randomized clinical trials. Regarding pathophysiological mechanisms, the most plausible explanation appears to be the influence of physical activity on reducing chronic inflammation and insulin resistance with a consequent positive effect on insulin growth factor 1 signaling pathways.

Exercise testing and cardiac rehabilitation in patients treated for cancer

Cardiovascular disease (CVD) is a major competing cause of morbidity and mortality in patients with cancer. Cancer treatment can have detrimental short- and long-term cardiovascular effects. Moreover, cancer patients may have a significant loss in cardiorespiratory fitness, a key CVD risk factor, during and after cancer treatment. Exercise training has emerged as a potential intervention to improve fitness and reduce the risk of CVD in cancer. In this review, we discuss the role of cardiorespiratory fitness to predict cancer and CVD outcomes, as well as explore the impact of exercise training to improve fitness and other key outcomes in patients with cancer. The role of cardio-oncology rehabilitation will also be highlighted.

IGF-Binding Proteins, Adiponectin, and Survival in Metastatic Colorectal Cancer: Results From CALGB (Alliance)/SWOG 80405

Background

Energy balance-related biomarkers are associated with risk and prognosis of various malignancies. Their relationship to survival in metastatic colorectal cancer (mCRC) requires further study.

Methods

Baseline plasma insulin-like growth factor (IGF)-1, IGF-binding protein (IGFBP)-3, IGFBP-7, C-peptide, and adiponectin were measured at time of trial registration in a prospective cohort of patients with mCRC participating in a National Cancer Institute–sponsored trial of first-line systemic therapy. We used Cox proportional hazards regression to adjust for confounders and examine associations of each biomarker with overall survival (OS) and progression-free survival (PFS). P values are 2-sided.

Results

Median follow-up for 1086 patients was 6.2 years. Compared with patients in the lowest IGFBP-3 quintile, patients in the highest IGFBP-3 quintile experienced an adjusted hazard ratio (HR) for OS of 0.57 (95% confidence interval [CI] = 0.42 to 0.78; P_nonlinearity < .001) and for PFS of 0.61 (95% CI = 0.45 to 0.82; P_trend = .003). Compared with patients in the lowest IGFBP-7 quintile, patients in the highest IGFBP-7 quintile experienced an adjusted hazard ratio for OS of 1.60 (95% CI = 1.30 to 1.97; P_trend < .001) and for PFS of 1.38 (95% CI = 1.13 to 1.69; P_trend < .001). Plasma C-peptide and IGF-1 were not associated with patient outcomes. Adiponectin was not associated with OS; there was a nonlinear U-shaped association between adiponectin and PFS (P_nonlinearity = .03).

Conclusions

Among patients with mCRC, high plasma IGFBP-3 and low IGFBP-7 were associated with longer OS and PFS. Extreme levels of adiponectin were associated with shorter PFS. These findings suggest potential avenues for prognostic and therapeutic innovation.

Insulin-Like Growth Factor 2 (IGF2) Signaling in Colorectal Cancer-From Basic Research to Potential Clinical Applications

Colorectal cancer (CRC) is one of the most common cancers in men and women worldwide as well as is the leading cause of death in the western world. Almost a third of the patients has or will develop liver metastases. While genetic as well as epigenetic mechanisms are important in CRC pathogenesis, the basis of the most cases of cancer is unknown. High spatial and inter-patient variability of the molecular alterations qualifies this cancer in the group of highly heterogeneous tumors, which makes it harder to elucidate the mechanisms underlying CRC progression. Determination of highly sensitive and specific early diagnosis markers and understanding the cellular and molecular mechanism(s) of cancer progression are still a challenge of the current era in oncology of solid tumors. One of the accepted risk factors for CRC development is overexpression of insulin-like growth factor 2 (IGF2), a 7.5-kDa peptide produced by liver and many other tissues. IGF2 is the first gene discovered to be parentally imprinted. Loss of imprinting (LOI) or aberrant imprinting of IGF2 could lead to IGF2 overexpression, increased cell proliferation, and CRC development. IGF2 as a mitogen is associated with increased risk of developing colorectal neoplasia. Higher serum IGF2 concentration as well as its tissue overexpression in CRC compared to control are associated with metastasis. IGF2 protein was one of the three candidates for a selective marker of CRC progression and staging. Recent research indicates dysregulation of different micro- and long non-coding RNAs (miRNAs and lncRNAs, respectively) embedded within the IGF2 gene in CRC carcinogenesis, with some of them indicated as potential diagnostic and prognostic CRC biomarkers. This review systematises the knowledge on the role of genetic and epigenetic instabilities of IGF2 gene, free (active form of IGF2) and IGF-binding protein (IGFBP) bound (inactive form), paracrine/autocrine secretion of IGF2, as well as mechanisms of inducing dysplasia in vitro and tumorigenicity in vivo. We have tried to answer which molecular changes of the IGF2 gene and its regulatory mechanisms have the most significance in initiation, progression (including liver metastasis), prognosis, and potential anti-IGF2 therapy in CRC patients.

Association between greater leg length and increased incidence of colorectal cancer: the atherosclerosis risk in communities (ARIC) study

PURPOSE

Previous studies have reported that taller people have an increased risk of colorectal cancer (CRC). We examined the association of two height components-leg length and sitting height-with CRC risk in 14,532 individuals aged 45-64 years in the Atherosclerosis Risk in Communities study.

METHODS

Anthropometrics were measured at baseline (1987-1989). Incident CRC cases (n = 382) were ascertained from 1987 to 2012. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios for CRC and colon cancer across quintiles of sex-specific leg length and sitting height.

RESULTS

The highest (versus the lowest) quintile of leg length was associated with a 36% greater CRC risk (p-trend = 0.04), and 51% greater colon cancer risk (p-trend = 0.01). For the top four quintiles combined, risk was increased by 34% for CRC and by 45% for colon cancer versus the lowest quintile. Total height and sitting height were not significantly associated with CRC or colon cancer risk. A small number of cases (n = 57) limited our ability to conduct subgroup analyses for rectal cancer.

CONCLUSIONS

A positive association of leg length with CRC and colon cancer risk suggests that biological mechanisms leading to greater leg length during puberty may explain the association between taller height and CRC.

Peer support for the maintenance of physical activity and health in cancer survivors: the PEER trial - a study protocol of a randomised controlled trial

Background

Despite an overwhelming body of evidence showing the benefits of physical activity (PA) and exercise for cancer survivors, few survivors meet the exercise oncology guidelines. Moreover, initiating, let alone maintaining exercise programs with cancer survivors continues to have limited success. The aim of this trial is to evaluate the influence of peer support on moderate-to-vigorous PA (MVPA) and various markers of health 12 months following a brief supervised exercise intervention in cancer survivors.

Methods

Men and women previously diagnosed with histologically-confirmed breast, colorectal or prostate cancer (n = 226), who are >1-month post-treatment, will be invited to participate in this trial. Once enrolled, participants will complete 4 weeks (12 sessions) of supervised high intensity interval training (HIIT). On completion of the supervised phase, both groups will be provided with written recommendations and verbally encouraged to achieve three HIIT sessions per week, or equivalent exercise that meets the exercise oncology guidelines. Participants will be randomly assigned to receive 12 months of peer support, or no peer support (control). Primary and secondary outcomes will be assessed at baseline, after the 4-week supervised HIIT phase and at 3-, 6- and 12-months. Primary outcomes will include accelerometry-derived MVPA and prescribed HIIT session adherence; whilst secondary outcomes will include cardiorespiratory fitness (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}} $$\end{document}V˙O2peak), body composition, quality of life and select cytokines, myokines and inflammatory markers. Random effects mixed modelling will be used to compare mean changes in outcomes between groups at each time point. A group x time interaction will be used to formally test for differences between groups (alpha =0.05); utilising intention-to-treat analyses.

Discussion

If successful, peer support may be proposed, adopted and implemented as a strategy to encourage cancer survivors to maintain exercise beyond the duration of a short-term, supervised intervention. A peer support-exercise model has the long-term potential to reduce comorbidities, improve physical and mental wellbeing, and significantly reduce the burden of disease in cancer survivors.

Ethics

Human Research Ethics Committee of Bellberry Ltd. (#2015–12-840).

Trial registration

Australian New Zealand Clinical Trial Registry 12618001855213. Retrospectively registered 14 November 2018.

Trial registration includes all components of the WHO Trial Registration Data Set, as recommended by the ICMJE.

Effect of exercise on colorectal cancer prevention and treatment

In recent years, because of improved cancer screening, detection and treatment modalities, a rapid increase in the population of colorectal and other cancer survivors has been observed. The increasing population has justified the requirement of preventive strategies such as lifestyle modifications with regard to obesity, physical activity, diet and smoking. Physical activity may prevent approximately 15% of the colon cancers. Furthermore, several observational studies have demonstrated the efficacy and dose-dependent and anti-cancer effects of exercise on decreasing the mortality and risk of recurrence before and after the colorectal cancer (CRC) diagnosis. However, the required exercise dose, type and intensity are yet unclear. The results of randomised prospective studies are expected to determine the optimal amount, type and intensity of exercise and formulate the most appropriate exercise plan and guidelines, according to the requirements and comorbidities of the patients. In addition, recent studies have focused on the molecular and genetic mechanisms underlying the effect of physical activity on disease outcomes and recurrence rates. This review aimed to investigate the effects of physical activity and the biological basis of these effects in preventing the risk and recurrence of CRC and decreasing the hazards of cancer and cancer treatment.

Integrative Treatment for Colorectal Cancer: A Comprehensive Approach

A comprehensive approach to integrative treatment of colorectal cancer (CRC) patients involves three spheres of intervention: lifestyle, biology, and conventional treatment. Individualization of treatment is emphasized. The lifestyle sphere includes nutritional therapies, biobehavioral strategies with circadian interventions, and physical care modalities. The biology sphere comprises six host factors in the patient's internal biochemical environment or "terrain": inflammation, glycemia, oxidative stress, immune dysregulation, coagulopathy, and stress chemistries. Laboratory testing of these factors guides integrative lifestyle and supplement recommendations. The conventional treatment sphere includes individualized lifestyle recommendations, and supplements or drugs used to enhance tolerability or effectiveness of conventional treatments. Innovative strategies are implemented, including chronomodulated chemotherapy, chemosensitivity testing, and using results of molecular genomic testing to guide nutritional infusions and supplement recommendations. In the lifestyle sphere, substantial evidence from cohort studies supports recommendations for a diet that emphasizes plant and fish proteins, healthful fats in amounts that are tailored to the clinical circumstance of the patient, and carbohydrates based on unrefined whole grains, vegetables and whole fruits. High glycemic diets and refined carbohydrates, especially sugar-sweetened beverages, should be avoided. Biobehavioral strategies include practice of the relaxation response and related approaches. In addition, specific strategies to promote robust circadian organization (CO) are used to combat quality of life concerns and worsened survival that accompany disrupted CO. Physical activity, including aerobic activity and muscle strengthening, is recommended at all disease stages. In the biology sphere, supplements and lifestyle recommendations for inflammation and glycemia are discussed. In the conventional treatment sphere, supplements and innovative and complementary therapies that may remedy treatment toxicities are reviewed. Approaching CRC treatment with a comprehensive, individualized intervention enables safe and beneficial outcomes in this patient population, which can vary widely in individual biology, treatment toxicities, and disease complications. Further research in integrative therapies for CRC patients is needed.

Pre- and post-diagnosis physical activity is associated with survival benefits of colorectal cancer patients: a systematic review and meta-analysis

OBJECTIVE

Physical activity is associated with reduced risk of colorectal cancer. However, whether physical activity could impart cancer patients' survival benefits remains uncertain. The aim of this study is to systematically evaluate the relationship between physical activity and colorectal cancer mortality.

RESULTS

Our meta-analysis included 11 studies involving 17,295 patients with a follow-up period ranging from 3.8 to 11.9 years. Results indicated that physical activity was inversely associated with overall (RR = 0.81, 95% CI = 0.72-0.91) and colorectal cancer-specific mortality (RR = 0.79, 95% CI = 0.71-0.89) before the diagnosis of cancer, respectively. For physical activity after diagnosis, the pooled RRs of colorectal cancer-specific and total mortality were 0.77 (95% CI, 0.63-0.94) and 0.71 (95% CI, 0.63-0.81), respectively. Similar inverse associations between exercise and prognosis were found among colorectal cancer survivors who had high-level exercise compared with those who had low-level exercise or were inactive. There was no obvious evidence for publication bias among studies.

MATERIALS AND METHODS

We performed a systematic data search in PubMed, Cochrane Library databases and Web of Science for relevant articles before Jan 2016. We adopted adjusted estimates to calculate pooled relative risks (RRs) with 95% confidence intervals (CI) by the random-effects model. The publication bias was assessed by Begg's test.

CONCLUSIONS

Our meta-analysis provides comprehensive evidence that physical activity, whether before or after the diagnosis of colorectal cancer, is related to reduced overall and cancer-specific mortality. Our findings may have significant public health implications and more prospective randomized clinical trials should be warranted to certify this protective association.

Prediagnosis Sleep Duration, Napping, and Mortality Among Colorectal Cancer Survivors in a Large US Cohort

Study Objectives

Prediagnosis lifestyle factors can influence colorectal cancer (CRC) survival. Sleep deficiency is linked to metabolic dysfunction and chronic inflammation, which may contribute to higher mortality from cardiometabolic conditions and promote tumor progression. We hypothesized that prediagnosis sleep deficiency would be associated with poor CRC survival. No previous study has examined either nighttime sleep or daytime napping in relation to survival among men and women diagnosed with CRC.

Methods

We examined self-reported sleep duration and napping prior to diagnosis in relation to mortality among 4869 CRC survivors in the NIH-AARP Diet and Health Study. Vital status was ascertained by linkage to the Social Security Administration Death Master File and the National Death Index. We examined the associations of sleep and napping with mortality using traditional Cox regression (total mortality) and Compositing Risk Regression (cardiovascular disease [CVD] and CRC mortality). Models were adjusted for confounders (demographics, cancer stage, grade and treatment, smoking, physical activity, and sedentary behavior) as well as possible mediators (body mass index and health status) in separate models.

Results

Compared to participants reporting 7-8 hours of sleep per day, those who reported <5 hr had a 36% higher all-cause mortality risk (Hazard Ratio (95% Confidence Interval), 1.36 (1.08-1.72)). Short sleep (<5 hr) was also associated with a 54% increase in CRC mortality (Substitution Hazard Ratio (95% Confidence Interval), 1.54 (1.11-2.14)) after adjusting for confounders and accounting for competing causes of death. Compared to no napping, napping 1 hr or more per day was associated with significantly higher total and CVD mortality but not CRC mortality.

Conclusion

Prediagnosis short sleep and long napping were associated with higher mortality among CRC survivors.

SNPs in the Insulin-Like Growth Factor Gene and Obesity Impact on Colorectal Cancer in Egyptians

Background and aims:

The insulin pathway may play a role in development of colorectal cancer (CRC). In this study, we investigated associations between CRC and obesity in Egyptians with reference to single nucleotide polymorphisms (SNPs) in the insulin-like growth factor-1 (IGF-I) gene. We also studied serum levels of IGF-1in Egyptian CRC patients with different BMI values.

Methods:

This prospective study included 66 CRC patients and 30 healthy individuals, for whom body mass index (BMI) was estimated, patients and controls being categorized into overweight or obese in one group and average weight in the other. Serum levels of IGF-1 were assessed by ELISA and SNPs in the IGF-I gene at rs6214C/T, rs6220 T/C and rs35767 C/T were examined by PCR- RFLP.

Results:

Serum levels of IGF-1 were significantly lower in both CRC average weight and overweight cases. IGF-1 could negatively predict CRC at a cut-off of 154 ng/ml with 87.5% sensitivity and 72.6 specificity. IGF-1 rs6214 CT and TT (T allele) genotypes were associated with a significantly increased risk of CRC. Univariate logistic regression showed that CRC risk significantly decreases by 0.14 for each one unit increase in IGF1.

Conclusion:

BMI could be considered as effect modifier for CRC risk. IGF-1 SNP rs6214 (TT and CT) are significantly associated with risk regardless of the BMI.

Epidemiology and biology of physical activity and cancer recurrence

Physical activity is emerging from epidemiologic research as a lifestyle factor that may improve survival from colorectal, breast, and prostate cancers. However, there is considerably less evidence relating physical activity to cancer recurrence and the biologic mechanisms underlying this association remain unclear. Cancer patients are surviving longer than ever before, and fear of cancer recurrence is an important concern. Herein, we provide an overview of the current epidemiologic evidence relating physical activity to cancer recurrence. We review the biologic mechanisms most commonly researched in the context of physical activity and cancer outcomes, and, using the example of colorectal cancer, we explore hypothesized mechanisms through which physical activity might intervene in the colorectal recurrence pathway. Our review highlights the importance of considering pre-diagnosis and post-diagnosis activity, as well as cancer stage and timing of recurrence, in epidemiologic studies. In addition, more epidemiologic research is needed with cancer recurrence as a consistently defined outcome studied separately from survival. Future mechanistic research using randomized controlled trials, specifically those demonstrating the exercise responsiveness of hypothesized mechanisms in early stages of carcinogenesis, are needed to inform recommendations about when to exercise and to anticipate additive or synergistic effects with other preventive behaviors or treatments.

Physical activity and survival of colorectal cancer patients: Population-based study from Germany

Increasing evidence shows physical activity to be associated with improved colorectal cancer (CRC) prognosis. However, large-scale prospective patient cohorts, comprehensively ascertaining physical activity, comprehensively considering potential variation by CRC stage and considering specific outcome measures, are sparse. Therefore, we aimed to evaluate the association of lifetime and latest prediagnostic leisure time physical activity with relevant prognostic outcomes in a large population-based cohort of CRC patients. 3,121 patients, diagnosed with CRC in 2003-2010 (median age: 69 years), were interviewed on sociodemographic and lifestyle factors, medication and comorbidities. Cancer recurrence, vital status and cause of death were documented over a median follow-up time of 4.8 years. Associations between lifetime and latest prediagnostic leisure time physical activity and overall, CRC-specific, recurrence-free and disease-free survival were evaluated with Cox regression. Latest but not lifetime leisure time physical activity [in metabolic task hours per week (MET-h/wk)] was associated with decreased overall and CRC-specific mortality (>56.2 vs. ≤13.2 MET-h/wk: adjusted hazard ratio (aHR)_{Overall/latest}  = 0.75; 95% confidence interval (CI) = 0.61-0.91; aHR_{CRC-specific/latest}  = 0.81; 95% CI = 0.64-1.02). In particular lifetime and latest walking were associated with decreased mortality (>20 vs. 0-10 MET-h/wk of walking: aHR_{Overall/latest}  = 0.66; 95% CI = 0.56-0.77; aHR_{CRC-specific/latest}  = 0.72; 95% CI = 0.60-0.87; aHR_{Overall/lifetime}  = 0.78; 95% CI = 0.66-0.93; aHR_{CRC-specific/lifetime}  = 0.71; 95% CI = 0.58-0.86). Associations were particularly pronounced for lifetime walking in metastatic (stage IV) and for latest walking in nonmetastatic disease patients. Prediagnostic physical activity was associated with improved CRC prognosis. Associations might be restricted to certain activities or depend on (non)metastatic disease state. Further optimization of activity recommendations and increase of recommendation adherence may help to improve patients' prognosis.

Physical exercise, reactive oxygen species and neuroprotection

Regular exercise has systemic beneficial effects, including the promotion of brain function. The adaptive response to regular exercise involves the up-regulation of the enzymatic antioxidant system and modulation of oxidative damage. Reactive oxygen species (ROS) are important regulators of cell signaling. Exercise, via intensity-dependent modulation of metabolism and/or directly activated ROS generating enzymes, regulates the cellular redox state of the brain. ROS are also involved in the self-renewal and differentiation of neuronal stem cells and the exercise-mediated neurogenesis could be partly associated with ROS production. Exercise has strong effects on the immune system and readily alters the production of cytokines. Certain cytokines, especially IL-6, IL-1, TNF-α, IL-18 and IFN gamma, are actively involved in the modulation of synaptic plasticity and neurogenesis. Cytokines can also contribute to ROS production. ROS-mediated alteration of lipids, protein, and DNA could directly affect brain function, while exercise modulates the accumulation of oxidative damage. Oxidative alteration of macromolecules can activate signaling processes, membrane remodeling, and gene transcription. The well known neuroprotective effects of exercise are partly due to redox-associated adaptation.

Metabolic syndrome contributes to an increased recurrence risk of non-metastatic colorectal cancer

Objectives

Epidemiological data suggests a close link between metabolic syndrome (MetS) and non-metastatic colorectal cancer (NMCRC). However, the relationship between MetS and the outcome of NMCRC is less well understood. We aim to evaluate the impact of MetS on the prognosis in NMCRC patients.

Methods

We performed a large cohort study of 1069 NMCRC patients. The Kaplan-Meier method was used to calculate the cumulative survival rate. Cox proportional hazard regression models were used to analyze the prognosis associated with MetS adjusting for clinicopathologic variables.

Results

MetS was identified in 20.7% of NMCRC patients. Patients with MetS were more likely to be older, higher levels of blood glucose, triglycerides, high density lipoprotein, and uric acid than patients without MS (P < 0.05 for all). During a mean period of 59.6 months follow-up, patients with MetS had a statistically significantly lower rate of disease-free survival (DFS) than the patients without MetS (P = 0.014), especially local recurrence (P = 0.040). However, there was no difference in overall survival (P = 0.116). Multivariate analysis showed that the presence of MetS was an independent risk factor for DFS (HR = 0.733, 95%CI 0.545–0.987, P = 0.041), but not for OS (P = 0.118).

Conclusions

MetS is associated with an increased recurrence risk of NMCRC.

The Influence of Exercise on the Insulin-like Growth Factor Axis in Oncology: Physiological Basis, Current, and Future Perspectives

Exercise and physical activity have been shown to reduce the risk of many common cancers and strongly influence tumor biology. A cause-effect mechanism explaining this relationship is dependent on cellular pathways that can influence tumor growth and are exercise responsive. The insulin-like growth factor (IGF) axis is reported to promote the development and progression of carcinomas through cellular signaling in cancerous tissues. This review summarizes the physiologic basis of the role of the IGF axis in oncology and the influence of exercise on this process. We examined the effects of exercise prescription on the IGF axis in cancer survivors by evaluating the current scope of the literature. The current research demonstrates a remarkable heterogeneity and inconsistency in the responses of the IGF axis to exercise in breast, prostate, and colorectal cancer survivors. Finally, this review presents an in-depth exploration of the physiologic basis and mechanistic underpinnings of the seemingly disparate relationship between exercise and the IGF axis in oncology. Although there is currently insufficient evidence to categorize the effects of exercise prescription on the IGF axis in cancer survivors, the inconsistency of results suggests a multifaceted relationship, the complexities of which are considered in this review.

Microenvironment acidity as a major determinant of tumor chemoresistance: Proton pump inhibitors (PPIs) as a novel therapeutic approach

Despite the major progresses in biomedical research and the development of novel therapeutics and treatment strategies, cancer is still among the dominant causes of death worldwide. One of the crucial challenges in the clinical management of cancer is primary (intrinsic) and secondary (acquired) resistance to both conventional and targeted chemotherapeutics. Multiple mechanisms have been identifiedthat underlie intrinsic and acquired chemoresistance: these include impaired drug uptake, increased drug efflux, deletion of receptors, altered drug metabolism, quantitative and qualitative alterations in drug targets, increased DNA damage repair and various mechanisms of anti-apoptosis. The fast efflux of anticancer drugs mediated by multidrug efflux pumps and the partial or complete reversibility of chemoresistance combined with the absence of genetic mutations suggests a multifactorial process. However, a growing body of recent evidence suggests that chemoresistance is often triggered by the highly acidic microenvironment of tumors. The vast majority of drugs, including conventional chemotherapeutics and more recent biological agents, are weak bases that are quickly protonated and neutralized in acidic environments, such as the extracellular microenvironment and the acidic organelles of tumor cells. It is therefore essential to develop new strategies to overcome the entrapment and neutralization of weak base drugs. One such strategy is the use of proton pump inhibitors which can enhance tumor chemosensitivity by increasing the pH of the tumor microenvironment. Recent clinical trials in animals with spontaneous tumors have indicated that patient alkalization is capable of reversing acquired chemoresistance in a large percentage of tumors that are refractory to chemotherapy. Of particular interest was the benefit of alkalization for patients undergoing metronomic regimens which are becoming more widely used in veterinary medicine. Overall, these results provide substantial new evidence that altering the acidic tumor microenvironment is an effective, well tolerated and low cost strategy for the overcoming of anticancer drug resistance.

Vitamin D Deficiency Adds an Element of Risk to Insulin Resistance in Colorectal Neoplasms

BACKGROUND

Both insulin resistance (IR) and vitamin D deficiency (VitDdef) have been suggested as risk factors for colorectal neoplasms (CRNs). However, the associations between the two with regard to CRNs are unclear.

AIMS

To determine whether IR is a risk factor for CRNs and whether VitDdef confers an additive risk of CRNs.

METHODS

Colonoscopy-naïve asymptomatic women undergoing a routine health screening program were analyzed. IR was defined as homeostatic model assessment of IR >3 and VitDdef set as <20 ng/mL. Multivariable logistic regression was performed between women with and without CRNs, matched for age and body mass index, to investigate associations with CRNs in IR, VitDdef, and VitDdef combined with IR.

RESULTS

We analyzed 216 women with CRNs and 216 without CRNs. A significant association was found between IR and CRNs (OR 1.838, 95 % CI 1.029-3.285, P = 0.040) but not with VitDdef. IR conferred a higher risk in advanced CRNs (OR 3.244, 95 % CI 1.588-6.631, P = 0.001) than CRNs. When VitDdef was combined with IR, risks of both CRNs and advanced CRNs increased (OR 2.131, 95 % CI 1.077-4.216, P = 0.030 and OR 4.438, 95 % CI 2.058-9.571, P < 0.001, respectively).

CONCLUSIONS

IR increases the risk of CRNs, and a combination of IR and VitDdef further increases this risk. As both VitDdef and IR are modifiable risk factors, such associations may have important clinical implications in the prevention of CRNs.

Genetic and dietary determinants of insulin-like growth factor (IGF)-1 and IGF binding protein (BP)-3 levels among Chinese women

Background

Higher insulin-like growth factor (IGF)-1 and lower IGF binding protein (BP)-3 levels have been associated with higher commoncancer risk, including breast cancer. Dietary factors, genetic polymorphisms, and the combination of both may influence circulating IGF-1 and IGFBP-3 serum concentrations.

Methods

From September 2011 to July 2012, we collected demographic, reproductive and dietary data on 143 women (≥40 years). We genotyped IGF-1 rs1520220 and IGFBP-3 rs2854744 and measured circulating IGF-1 and IGFBP-3 levels in serum. Covariance analyses were used to estimate the associations of serum levels of IGF-1 and IGFBP-3, and the molar ratio of IGF-1to IGFBP-3 with IGF-1 rs1520220 and IGFBP-3 rs2854744 genotypes. We subsequently assessed the combined influence of genetics and diet (daily intake of protein, fat and soy isoflavones) on IGF-1 and IGFBP-3 levels.

Results

Among women aged less than 50 years, circulating IGF-1 serum levels were significantly lower for those with CC genotype for IGF-1 rs1520220 than levels for those with the GC or GG genotypes (in recessive model: P = 0.007).In gene-diet analyses among these women, we found carrying CC genotype for IGF-1 rs1520220 and high soy isoflavone intake tend to be associated with lower circulating IGF-1 levels synthetically (P = 0.002). Women with GG or GC genotypes for IGF-1 rs1520220 and with low intake of soy isoflavones had the highest levels of circulating IGF-1 (geometric mean [95% CI]: 195 [37, 1021] µg/L). Comparatively, women with both the CC genotype and high soy intake had the lowest levels of circulating IGF-1 (geometric mean [95% CI]: 120 [38,378] µg/L).

Conclusions

IGF-1 serum levels are significantly lower among women with the CC genotype for IGF-1-rs1520220. High soy isoflavone intake may interact with carrying CC genotype for IGF-1-rs1520220 to lower women's serum IGF-1 levels more.