Survival Benefit of Exercise Differs by Tumor IRS1 Expression Status in Colorectal Cancer

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.

An immune-related gene prognostic prediction risk model for neoadjuvant chemoradiotherapy in rectal cancer using artificial intelligence

Background

This study aimed to establish and validate a prognostic model based on immune-related genes (IRGPM) for predicting disease-free survival (DFS) in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy, and to elucidate the immune profiles associated with different prognostic outcomes.

Methods

Transcriptomic and clinical data were sourced from the Gene Expression Omnibus (GEO) database and the West China Hospital database. We focused on genes from the RNA immune-oncology panel. The elastic net approach was employed to pinpoint immune-related genes significantly impacting DFS. We developed the IRGPM for rectal cancer using the random forest technique. Based on the IRGPM, we calculated prognostic risk scores to categorize patients into high-risk and low-risk groups. Comparative analysis of immune characteristics between these groups was conducted.

Results

In this study, 407 LARC samples were analyzed. The elastic net identified a signature of 20 immune-related genes, forming the basis of the IRGPM. Kaplan-Meier survival analysis revealed a lower 5-year DFS in the high-risk group compared to the low-risk group. The receiver operating characteristic (ROC) curve affirmed the model's robust predictive capability. Validation of the model was performed in the GSE190826 cohort and our institution's cohort. Gene expression differences between high-risk and low-risk groups predominantly related to cytokine-cytokine receptor interactions. Notably, the low-risk group exhibited higher immune scores. Further analysis indicated a greater presence of activated B cells, activated CD8 T cells, central memory CD8 T cells, macrophages, T follicular helper cells, and type 2 helper cells in the low-risk group. Additionally, immune checkpoint analysis revealed elevated PDCD1 expression in the low-risk group.

Conclusions

The IRGPM, developed through random forest and elastic net methodologies, demonstrates potential in distinguishing DFS among LARC patients receiving standard treatment. Notably, the low-risk group, as defined by the IRGPM, showed enhanced activation of adaptive immune responses within the tumor microenvironment.

Hippo pathway in intestinal diseases: focusing on ferroptosis

The incidence of intestinal diseases, such as inflammatory bowel disease, gastric cancer, and colorectal cancer, has steadily increased over the past decades. The Hippo pathway is involved in cell proliferation, tissue and organ damage, energy metabolism, tumor formation, and other physiologic processes. Ferroptosis is a form of programmed cell death characterized by the accumulation of iron and lipid peroxides. The Hippo pathway and ferroptosis are associated with various intestinal diseases; however, the crosstalk between them is unclear. This review elaborates on the current research on the Hippo pathway and ferroptosis in the context of intestinal diseases. We summarized the connection between the Hippo pathway and ferroptosis to elucidate the underlying mechanism by which these pathways influence intestinal diseases. We speculate that a mutual regulatory mechanism exists between the Hippo pathway and ferroptosis and these two pathways interact in several ways to regulate intestinal diseases.

Exercise Training Reduces the Inflammatory Response and Promotes Intestinal Mucosa-Associated Immunity in Lynch Syndrome

PURPOSE

Lynch syndrome (LS) is a hereditary condition with a high lifetime risk of colorectal and endometrial cancers. Exercise is a non-pharmacologic intervention to reduce cancer risk, though its impact on patients with LS has not been prospectively studied. Here, we evaluated the impact of a 12-month aerobic exercise cycling intervention in the biology of the immune system in LS carriers.

PATIENTS AND METHODS

To address this, we enrolled 21 patients with LS onto a non-randomized, sequential intervention assignation, clinical trial to assess the effect of a 12-month exercise program that included cycling classes 3 times weekly for 45 minutes versus usual care with a one-time exercise counseling session as control. We analyzed the effects of exercise on cardiorespiratory fitness, circulating, and colorectal-tissue biomarkers using metabolomics, gene expression by bulk mRNA sequencing, and spatial transcriptomics by NanoString GeoMx.

RESULTS

We observed a significant increase in oxygen consumption (VO2peak) as a primary outcome of the exercise and a decrease in inflammatory markers (prostaglandin E) in colon and blood as the secondary outcomes in the exercise versus usual care group. Gene expression profiling and spatial transcriptomics on available colon biopsies revealed an increase in the colonic mucosa levels of natural killer and CD8+ T cells in the exercise group that were further confirmed by IHC studies.

CONCLUSIONS

Together these data have important implications for cancer interception in LS, and document for the first-time biological effects of exercise in the immune system of a target organ in patients at-risk for cancer.

Association Between Recreational Physical Activity and mTOR Signaling Pathway Protein Expression in Breast Tumor Tissue

Physical activity (PA) is associated with decreased signaling in the mTOR pathway in animal models of mammary cancer, which may indicate favorable outcomes. We examined the association between PA and protein expression in the mTOR signaling pathway in breast tumor tissue. Data on 739 patients with breast cancer, among which 125 patients had adjacent-normal tissue, with tumor expression for mTOR, phosphorylated (p)-mTOR, p-AKT, and p-P70S6K were analyzed. Self-reported recreational PA levels during the year prior to diagnosis were classified using the Centers for Disease Control and Prevention guideline as sufficient (for moderate or vigorous) PA or insufficient PA (any PA but not meeting the guideline) or no PA. We performed linear models for mTOR protein and two-part gamma hurdle models for phosphorylated proteins. Overall, 34.8% of women reported sufficient PA; 14.2%, insufficient PA; 51.0%, no PA. Sufficient (vs. no) PA was associated with higher expression for p-P70S6K [35.8% increase; 95% confidence interval (CI), 2.6-80.2] and total phosphoprotein (28.5% increase; 95% CI, 5.8-56.3) among tumors with positive expression. In analyses stratified by PA intensity, sufficient versus no vigorous PA was also associated with higher expression levels of mTOR (beta = 17.7; 95% CI, 1.1-34.3) and total phosphoprotein (28.6% higher; 95% CI, 1.4-65.0 among women with positive expression) in tumors. The study found that guideline-concordant PA levels were associated with increased mTOR signaling pathway activity in breast tumors. Studying PA in relation to mTOR signaling in humans may need to consider the complexity of the behavioral and biological factors.

Significance

PA increases energy expenditure and limits energy utilization in the cell, which can influence the mTOR pathway that is central to sensing energy influx and regulating cell growth. We studied exercise-mediated mTOR pathway activities in breast tumor and adjacent-normal tissue. Despite the discrepancies between animal and human data and the limitations of our approach, the findings provide a foundation to study the mechanisms of PA and their clinical implications.

High Expression MicroRNA-206 Inhibits the Growth of Tumor Cells in Human Malignant Fibrous Histiocytoma

Background: Malignant fibrous histiocytoma (MFH) is a common type of soft tissue sarcoma and a serious threat to human health. MFH often relapses locally after the curettage is related to the residual cancer stem cells (CSCs). Currently, the dysregulation of microRNA (miRNA) has been found to be closely related to the recurrence of CSCs. However, whether dysregulations of miRNAs exist in MFH, CSCs remained unknown.

Methods: In this study, miRNAs in MFH CSCs and MFH common cells were examined by gene probe. Then, target genes and their functions involved in the signal pathway were predicted by the relevant database. Finally, the miRNAs’ target regulatory network was constructed. Furthermore, the miRNAs and target genes were identified by quantitative polymerase chain reaction, whereas miRNA analogs and antagonists were transfected in tumor cells to investigate cell proliferation ability further.

Results: Results showed that a total of 47 miRNAs were found, including 16 that were upregulated and 31 that were downregulated. The screened differential miRNA showed a different expression in the cell resistant strains compared with the control group. Quantitative polymerase chain reaction analysis confirmed that the relative abundance of seven miRNAs and four target genes varied significantly. The encouraging issue is that we found Hsa-miR-206 significantly inhibited MFH proliferative activity.

Conclusion: Hsa-miR-206 played a key role in regulating MFH CSC properties that might be a representative marker and target for the diagnosis and treatment of MFH in the future.

Factors influencing physical activity participation among people living with or beyond cancer: a systematic scoping review

BACKGROUND

It has been posited that physical activity (PA) has the potential to improve health outcomes and the health-related quality of life of people living with or beyond cancer. Despite the well-documented health benefits of PA, there is a low level of PA among cancer patients. A systematic scoping review was conducted to investigate attitudes, perceptions, preferences and barriers vs. facilitators to cancer patients' PA participation.

METHODS

A systematic search was performed across four automated databases (PubMed, Embase, PsycINFO and Medline) in keeping with the PRISMA guideline. All cancer types were included, and any age/gender groups were eligible. Both qualitative and quantitative studies were included. The Health Belief Model provided a conceptual framework for the conduct of the scoping review as well as guiding thinking to inform evidence-based interventions.

RESULTS

Ninety-eight articles were included in this review. Nearly half of the studies focused on mixed cancer sites; breast cancer was the most commonly examined cancer type (19%). Post-treatment was the most commonly investigated stage (33%), followed by studies of mixed stages of the cancer trajectory (27%), the acute treatment stage (23%) and pre-treatment stage (1%). Patient treatment stage was not reported in 16% of studies. Cancer patients reported positive attitudes to PA and recognized its benefits for health and wellbeing. Cancer-related side effects (e.g. fatigue) were a leading physiological barrier to PA participation, whereas effective symptom management techniques/tools acted as a powerful facilitator. Psychosocial barriers included low motivation and kinesiophobia, and perceived health benefits and social support/guidance by healthcare providers were significant facilitators. Inaccessible fitness facilities hindered cancer patients' PA engagement though the availability of tailored amenities appeared to be a strong facilitator. PA preferences varied in terms of type, place, time, company and source of information and pointed to the need for individualized PA programs.

CONCLUSIONS

There is a need for further research to identify barriers and facilitators to PA that are faced by patients with particular cancer types. Recommended PA promoting-strategies involve including exercise science professionals in healthcare teams and ensuring that fitness facilities are accessible.

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.

Night-Shift Work Duration and Risk of Colorectal Cancer According to IRS1 and IRS2 Expression

BACKGROUND

We hypothesized that the risk of colorectal cancer in night-shift workers might be different according to insulin receptor substrate status.

METHODS

Among 77,470 eligible women having night work assessed in the Nurses' Health Study, we documented a total of 1,397 colorectal cancer cases, of which 304 or 308 had available data on IRS1 and IRS2, respectively. We used duplication-method Cox proportional hazards regression analysis for competing risks to calculate HRs and 95% confidence intervals (CI) for each colorectal cancer subtype. We measured tumor IRS1 or IRS2 expression by immunohistochemistry (IHC).

RESULTS

Compared with women who never worked night shifts, those working ≥15 years night shifts had a marginal trend of increased overall risk of colorectal cancer (P trend = 0.06; multivariable HR = 1.20; 95% CI, 0.99-1.45). Longer duration of night-shift work was associated with a higher risk of IRS2-positive tumors (multivariable HR = 2.69; 95% CI, 1.48-4.89; P trend = 0.001, ≥15 years night shifts vs. never) but not with IRS2-negative tumors (multivariable HR = 0.90; 95% CI, 0.54-1.51; P trend = 0.72; P heterogeneity for IRS2 = 0.008). Similarly, the corresponding multivariable HRs were 1.81 for IRS1-positive tumors (95% CI, 0.94-3.48; P trend = 0.06) and 1.13 for IRS1-negative tumors (95% CI, 0.71-1.80; P trend = 0.56; P heterogeneity for IRS1 = 0.02).

CONCLUSIONS

Our molecular pathologic epidemiology data suggest a potential role of IRS in mediating carcinogenesis induced by night-shift work.

IMPACT

Although these findings need validation, rotating night shift might increase colorectal cancer risk in women with abnormal insulin receptor pathways.

PYCR1 interference inhibits cell growth and survival via c-Jun N-terminal kinase/insulin receptor substrate 1 (JNK/IRS1) pathway in hepatocellular cancer

BACKGROUND

Liver cancer is the second leading causes of cancer-related death globally. Pyrroline-5-carboxylate reductase 1 (PYCR1) plays a critical role in metabolic profiles of tumors. Therefore, it is necessary to explore the mechanisms of PYCR1 on cell growth and survival in hepatocellular carcinoma (HCC).

METHODS

Protein and mRNA expression levels of PYCR1 in 140 pairs of tumor and adjacent normal liver tissues of HCC patients were analyzed by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). Expressions of PYCR1 were inhibited in BEL-7404 cells and SMMC-7721 cells using gene interference technology. The cell proliferation was detected by Celigo and MTT assay. The colony formation assay was also performed. The cell apoptosis was measured by flow cytometric assay. The effect of PYCR1 interference on tumor growth was observed by xenograft nude mice assay in vivo. The downstream pathway of PYCR1 interference was searched by microarray and bioinformatics analysis, and validated by qRT-PCR and western blot.

RESULTS

PYCR1 levels were significantly up-regulated in HCC tumor tissues than adjacent normal liver tissues in both protein and mRNA levels (P < 0.01). In vitro, the cell proliferation was significantly slower in shPYCR1 group than shCtrl group in BEL-7404 and SMMC-7721 cells (P < 0.001). The colony number was significantly smaller after PYCR1 interference (P < 0.01). The percentage of apoptosis cells significantly increased in shPYCR1 group (P < 0.01). In vivo, PYCR1 interference could obviously suppress tumor growth in xenograft nude mice. The volume and weight of tumors were significantly smaller via PYCR1 interference. The c-Jun N-terminal kinase (JNK) signaling pathway significantly altered, and insulin receptor substrate 1 (IRS1) were significantly down-regulated by PYCR1 interference in both mRNA and protein levels (P < 0.001).

CONCLUSION

PYCR1 interference could inhibit cell proliferation and promote cell apoptosis in HCC through regluting JNK/IRS1 pathway. Our study will provide a drug target for HCC therapy and a potential biomarker for its diagnosis or prognosis.

Knockdown of long noncoding RNA PVT1 suppresses cell proliferation and invasion of colorectal cancer via upregulation of microRNA-214-3p

Long noncoding RNAs (lncRNAs) have been reported to be involved in the occurrence and tumorigenesis of numerous malignant cancers. Microarray expression profiles were used to screen colorectal cancer (CRC)-related differentially expressed genes and lncRNAs, which revealed that insulin receptor substrate 1 (IRS1) and lncRNA plasmacytoma variant translocation 1 (PVT1) were highly expressed in CRC. This study aimed to investigate the regulatory role of lncRNA PVT1 in CRC. Subcellular localization detected by fluorescence in situ hybridization identified that lncRNA PVT1 was primarily located in the cytoplasm. The interaction between lncRNA PVT1 and microRNA-214-3p (miR-214-3p) and IRS1 was predicted using the RNA22 website. Next the dual luciferase reporter gene assay, RNA pull-down, and RNA immunoprecipitation assays verified lncRNA PVT1 to be a competitive endogenous RNA (ceRNA) against miR-214-3p, and IRS1 was found to be a target of miR-214-3p. The expression pattern of lncRNA PVT1, miR-214-3p, IRS1, phosphoinositide 3-kinase (PI3K), and Akt was characterized in response to lncRNA PVT1 silencing or miR-214-3p upregulation. Meanwhile, their regulatory effects on cell proliferation, invasion, and apoptosis were detected in CRC cells. With increased levels of miR-214-3p and decreased levels of lncRNA PVT1 in CRC cells, the expression of phosphatidylinositol 3-kinase, putative (PI3K) and Akt was reduced, and consequently, the cell apoptosis was stimulated and cell proliferation and invasion were suppressed. All in all, lncRNA PVT1 competitively binds to miR-214-3p to upregulate the expression of IRS1 thus activating the PI3K/Akt signaling pathway, thus accelerating CRC progression. This study suggests that lncRNA PVT1 might be a potential target of therapeutic strategies for CRC treatment.NEW & NOTEWORTHY This study mainly suggests that long noncoding (lnc)RNA plasmacytoma variant translocation 1 (PVT1) is a downregulated lncRNA in colorectal cancer (CRC), accelerating CRC progression. Strikingly, lncRNA PVT1 acts as a competitive endogenous RNA against microRNA (miR)-214-3p, whereas miR-214-3p targets insulin receptor substrate 1, which draws a comprehensive picture of the potential molecular mechanisms of lncRNA PVT1 in CRC.

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.

Physical Activity and Colorectal Cancer Prognosis According to Tumor-Infiltrating T Cells

Background

Evidence suggests that high-level physical activity may potentially reduce cancer mortality through its immune enhancement effect. We therefore hypothesized that survival benefits associated with physical activity might be stronger in colorectal carcinomas with lower immune reaction at diagnosis.

Methods

Using molecular pathological epidemiology databases of 470 colon and rectal carcinoma cases in the Nurses’ Health Study and the Health Professionals Follow-up Study, we assessed the prognostic association of postdiagnosis physical activity in strata of densities of CD3⁺ cells, CD8⁺ cells, CD45RO (PTPRC)⁺ cells, or FOXP3⁺ cells in tumor tissue. Cox proportional hazards regression model was used to adjust for potential confounders, including microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element-1 methylation, KRAS, BRAF, and PIK3CA mutations, and expression of CTNNB1 (beta-catenin), PTGS2 (cyclooxygenase-2), and IRS1.

Results

The association of postdiagnosis physical activity with colorectal cancer-specific mortality differed by CD3⁺ cell density (P_interaction < .001). Multivariable-adjusted colorectal cancer-specific mortality hazard ratios for a quartile-unit increase in physical activity were 0.56 (95% confidence interval = 0.38 to 0.83) among cases with the lowest quartile of CD3⁺ cell density compared with 1.14 (95% confidence interval = 0.79 to 1.65) in cases with the highest quartile. We observed no differential survival association of physical activity by densities of CD8⁺ cells, CD45RO⁺ cells, or FOXP3⁺ cells.

Conclusions

The association between postdiagnosis physical activity and colorectal cancer survival appeared stronger for carcinomas with lower T cell infiltrates, suggesting an interactive effect of exercise and immunity on colorectal cancer progression.

Energy balance and gastrointestinal cancer: risk, interventions, outcomes and mechanisms

Obesity increases the risk of multiple gastrointestinal cancers and worsens disease outcomes. Conversely, strong inverse associations have emerged between physical activity and colon cancer and possibly other gastrointestinal malignancies. The effect of weight loss interventions - such as modifications of diet and/or physical activity or bariatric surgery - remains unclear in patients who are obese and have gastrointestinal cancer, although large clinical trials are underway. Human intervention studies have already shed light on potential mechanisms underlying the energy balance-cancer relationship, with preclinical models supporting emerging pathway effects. Central to interventions that reduce obesity or increase physical activity are pluripotent cancer-preventive effects (including reduced systemic and adipose tissue inflammation and angiogenesis, altered adipokine levels and improved insulin resistance) that directly interface with the hallmarks of cancer. Other mechanisms, such as DNA repair, oxidative stress and telomere length, immune function, effects on cancer stem cells and the microbiome, could also contribute to energy balance effects on gastrointestinal cancers. Although some mechanisms are well understood (for instance, systemic effects on inflammation and insulin signalling), other areas remain unclear. The current state of knowledge supports the need to better integrate mechanistic approaches with preclinical and human studies to develop effective, personalized diet and exercise interventions to reduce the burden of obesity on gastrointestinal cancer.

The Impact of Exercise on Cancer Mortality, Recurrence, and Treatment-Related Adverse Effects

The combination of an increasing number of new cancer cases and improving survival rates has led to a large and rapidly growing population with unique health-care requirements. Exercise has been proposed as a strategy to help address the issues faced by cancer patients. Supported by a growing body of research, major health organizations commonly identify the importance of incorporating exercise in cancer care and advise patients to be physically active. This systematic review comprehensively summarizes the available epidemiologic and randomized controlled trial evidence investigating the role of exercise in the management of cancer. Literature searches focused on determining the potential impact of exercise on 1) cancer mortality and recurrence and 2) adverse effects of cancer and its treatment. A total of 100 studies were reviewed involving thousands of individual patients whose exercise behavior was assessed following the diagnosis of any type of cancer. Compared with patients who performed no/less exercise, patients who exercised following a diagnosis of cancer were observed to have a lower relative risk of cancer mortality and recurrence and experienced fewer/less severe adverse effects. The findings of this review support the view that exercise is an important adjunct therapy in the management of cancer. Implications on cancer care policy and practice are discussed.

Physical Activity and Outcomes in Patients with Stage III Colon Cancer: A Correlative Analysis of Phase III Trial NCCTG N0147 (Alliance)

Background: Prior studies have supported an inverse association between physical activity and colon cancer risk and suggest that higher physical activity may also improve cancer survival. Among participants in a phase III adjuvant trial for stage III colon cancer, we assessed the association of physical activity around the time of cancer diagnosis with subsequent outcomes.Methods: Before treatment arm randomization (FOLFOX or FOLFOX + cetuximab), study participants completed a questionnaire including items regarding usual daily activity level and frequency of participation in recreational physical activity (N = 1,992). Using multivariable Cox models, we calculated HRs for associations of aspects of physical activity with disease-free (DFS) and overall survival (OS).Results: Over follow-up, 505 participants died and 541 experienced a recurrence. Overall, 75% of participants reported recreational physical activity at least several times a month; for participants who reported physical activity at least that often (vs. once a month or less), the HRs for DFS and OS were 0.82 [95% confidence interval (CI), 0.69-0.99] and 0.76 (95% CI, 0.63-0.93), respectively. There was no evidence of material effect modification in these associations by patient or tumor attributes, except that physical activity was more strongly inversely associated with OS in patients with stage T3 versus T4 tumors (P_interaction = 0.03).Conclusions: These findings suggest that higher physical activity around the time of colon cancer diagnosis may be associated with more favorable colon cancer outcomes.Impact: Our findings support further research on whether colon cancer survival may be enhanced by physical activity. Cancer Epidemiol Biomarkers Prev; 27(6); 696-703. ©2018 AACR.

Dose-response effects of exercise on insulin among colon cancer survivors

Physical activity is associated with a lower risk of disease recurrence among colon cancer survivors. The pathways through which physical activity may alter disease outcomes are unknown, but may include changes in metabolic growth factors, such as insulin. Between January 2015 and August 2015, 39 stage I-III colon cancer survivors were randomized to one of the three groups: usual care control, 150 min/week of aerobic exercise (low-dose) and 300 min/week of aerobic exercise (high-dose) for six months. The pre-specified key metabolic growth factor outcome was fasting insulin. Insulin resistance was quantified using the homeostatic model assessment. Mean age was 56.5 ± 10.0 years, 51% had stage III disease, 72% were treated with chemotherapy and the mean time since finishing treatment was 10.9 ± 6.1 months. Over six months, the low-dose group completed 141.5 ± 9.9 min/week of aerobic exercise, and the high-dose group completed 247.2 ± 10.7 min/week of aerobic exercise. Fasting insulin concentrations decreased 7.4 ± 9.4 pmol/L in the control group, 28.0 ± 8.3 pmol/L in the low-dose group and 20.7 ± 9.3 pmol/L in the high-dose group (nonlinear Ptrend = 0.042). Insulin resistance decreased 0.11 ± 0.20 in the control group, 0.63 ± 0.17 in the low-dose group and 0.43 ± 0.19 in the high-dose group (nonlinear Ptrend = 0.012). Aerobic exercise reduces insulin concentrations and insulin resistance among patients with stage I-III colon cancer. Prescribing 150 min/week of aerobic exercise may be sufficient for reducing insulin concentrations and insulin resistance, which may partially mediate the relationship between physical activity and colon cancer prognosis.

Exercise-dependent regulation of the tumour microenvironment

The integrity and composition of the tumour microenvironment (TME) is highly plastic, undergoing constant remodelling in response to instructive signals derived from alterations in the availability and nature of systemic host factors. This 'systemic milieu' is directly modulated by host exposure to modifiable lifestyle factors such as exercise. Host exposure to regular exercise markedly reduces the risk of the primary development of several cancers and might improve clinical outcomes following a diagnosis of a primary disease. However, the molecular mechanisms that underpin the apparent antitumour effects of exercise are poorly understood. In this Opinion article, we explore the putative effects of exercise in reprogramming the interaction between the host and the TME. Specifically, we speculate on the possible effects of exercise on reprogramming 'distant' tissue microenvironments (those not directly involved in the exercise response) by analysing how alterations in the systemic milieu might modulate key TME components to influence cancer hallmarks.

A novel feature ranking method for prediction of cancer stages using proteomics data

Proteomic analysis of cancers' stages has provided new opportunities for the development of novel, highly sensitive diagnostic tools which helps early detection of cancer. This paper introduces a new feature ranking approach called FRMT. FRMT is based on the Technique for Order of Preference by Similarity to Ideal Solution method (TOPSIS) which select the most discriminative proteins from proteomics data for cancer staging. In this approach, outcomes of 10 feature selection techniques were combined by TOPSIS method, to select the final discriminative proteins from seven different proteomic databases of protein expression profiles. In the proposed workflow, feature selection methods and protein expressions have been considered as criteria and alternatives in TOPSIS, respectively. The proposed method is tested on seven various classifier models in a 10-fold cross validation procedure that repeated 30 times on the seven cancer datasets. The obtained results proved the higher stability and superior classification performance of method in comparison with other methods, and it is less sensitive to the applied classifier. Moreover, the final introduced proteins are informative and have the potential for application in the real medical practice.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype

We have previously shown that commonly expressed miRNAs influenced tumor molecular phenotype in colorectal cancer. We hypothesize that infrequently expressed miRNAs, when showing higher levels of expression, help to define tumor molecular phenotype. In this study, we examine 304 miRNAs expressed in at least 30 individuals, but in <50% of the population and with a mean level of expression above 1.0 relative florescent unit. We examine associations in 1893 individuals who have the tumor molecular phenotype data as well as miRNA expression levels for both carcinoma and normal colorectal tissue. We compare miRNAs uniquely associated with tumor molecular phenotype to the RNAseq data to identify genes associated with these miRNAs. This information is used to further identify unique pathways associated with tumor molecular phenotypes of TP53-mutated, KRAS-mutated, CpG island methylator phenotype and microsatellite instability tumors. Thirty-seven miRNAs were uniquely associated with TP53-mutated tumors; 30 of these miRNAs had higher level of expression in TP53-mutated tumors, while seven had lower levels of expression. Of the 34 miRNAs associated with CpG island methylator phenotype-high tumors, 16 were more likely to have a CpG island methylator phenotype-high tumor and 19 were less likely to be CpG island methylator phenotype-high. For microsatellite instability, 13 of the 22 infrequently expressed miRNAs were significantly less likely to be expressed in microsatellite unstable tumors. KRAS-mutated tumors were not associated with any miRNAs after adjustment for multiple comparisons. Of the dysregulated miRNAs, 17 were more likely to be TP53-mutated tumors while simultaneously being less likely to be CpG island methylator phenotype-high and/or microsatellite instability tumors. Genes regulated by these miRNAs were involved in numerous functions and pathways that influence cancer risk and progression. In summary, some infrequently expressed miRNAs, when expressed at higher levels, appear to have significant biological meaning in terms of tumor molecular phenotype and gene expression profiles.

Biomarker correlation network in colorectal carcinoma by tumor anatomic location

Background

Colorectal carcinoma evolves through a multitude of molecular events including somatic mutations, epigenetic alterations, and aberrant protein expression, influenced by host immune reactions. One way to interrogate the complex carcinogenic process and interactions between aberrant events is to model a biomarker correlation network. Such a network analysis integrates multidimensional tumor biomarker data to identify key molecular events and pathways that are central to an underlying biological process. Due to embryological, physiological, and microbial differences, proximal and distal colorectal cancers have distinct sets of molecular pathological signatures. Given these differences, we hypothesized that a biomarker correlation network might vary by tumor location.

Results

We performed network analyses of 54 biomarkers, including major mutational events, microsatellite instability (MSI), epigenetic features, protein expression status, and immune reactions using data from 1380 colorectal cancer cases: 690 cases with proximal colon cancer and 690 cases with distal colorectal cancer matched by age and sex. Edges were defined by statistically significant correlations between biomarkers using Spearman correlation analyses. We found that the proximal colon cancer network formed a denser network (total number of edges, n = 173) than the distal colorectal cancer network (n = 95) (P < 0.0001 in permutation tests). The value of the average clustering coefficient was 0.50 in the proximal colon cancer network and 0.30 in the distal colorectal cancer network, indicating the greater clustering tendency of the proximal colon cancer network. In particular, MSI was a key hub, highly connected with other biomarkers in proximal colon cancer, but not in distal colorectal cancer. Among patients with non-MSI-high cancer, BRAF mutation status emerged as a distinct marker with higher connectivity in the network of proximal colon cancer, but not in distal colorectal cancer.

Conclusion

In proximal colon cancer, tumor biomarkers tended to be correlated with each other, and MSI and BRAF mutation functioned as key molecular characteristics during the carcinogenesis. Our findings highlight the importance of considering multiple correlated pathways for therapeutic targets especially in proximal colon cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-017-1718-5) contains supplementary material, which is available to authorized users.

Dietary glycemic and insulin scores and colorectal cancer survival by tumor molecular biomarkers

Accumulating evidence suggests that post-diagnostic insulin levels may influence colorectal cancer (CRC) survival. Yet, no previous study has examined CRC survival in relation to a post-diagnostic diet rich in foods that increase post-prandial insulin levels. We hypothesized that glycemic and insulin scores (index or load; derived from food frequency questionnaire data) may be associated with survival from specific CRC subtypes sensitive to the insulin signaling pathway. We prospectively followed 1,160 CRC patients from the Nurses' Health Study (1980-2012) and Health Professionals Follow-Up Study (1986-2012), resulting in 266 CRC deaths in 10,235 person-years. CRC subtypes were defined by seven tumor biomarkers (KRAS, BRAF, PIK3CA mutations, and IRS1, IRS2, FASN and CTNNB1 expression) implicated in the insulin signaling pathway. For overall CRC and each subtype, hazard ratio (HR) and 95% confidence interval (95% CI) for an increase of one standard deviation in each of glycemic and insulin scores were estimated using time-dependent Cox proportional hazards model. We found that insulin scores, but not glycemic scores, were positively associated with CRC mortality (HR = 1.19, 95% CI = 1.02-1.38 for index; HR = 1.23, 95% CI = 1.04-1.47 for load). The significant positive associations appeared more pronounced among PIK3CA wild-type cases and FASN-negative cases, with HR ranging from 1.36 to 1.60 across insulin scores. However, we did not observe statistically significant interactions of insulin scores with PIK3CA, FASN, or any other tumor marker (p interaction > 0.12). While additional studies are needed for definitive evidence, a high-insulinogenic diet after CRC diagnosis may contribute to worse CRC survival.

Molecular pathological epidemiology: new developing frontiers of big data science to study etiologies and pathogenesis

Molecular pathological epidemiology (MPE) is an integrative field that utilizes molecular pathology to incorporate interpersonal heterogeneity of a disease process into epidemiology. In each individual, the development and progression of a disease are determined by a unique combination of exogenous and endogenous factors, resulting in different molecular and pathological subtypes of the disease. Based on "the unique disease principle," the primary aim of MPE is to uncover an interactive relationship between a specific environmental exposure and disease subtypes in determining disease incidence and mortality. This MPE approach can provide etiologic and pathogenic insights, potentially contributing to precision medicine for personalized prevention and treatment. Although breast, prostate, lung, and colorectal cancers have been among the most commonly studied diseases, the MPE approach can be used to study any disease. In addition to molecular features, host immune status and microbiome profile likely affect a disease process, and thus serve as informative biomarkers. As such, further integration of several disciplines into MPE has been achieved (e.g., pharmaco-MPE, immuno-MPE, and microbial MPE), to provide novel insights into underlying etiologic mechanisms. With the advent of high-throughput sequencing technologies, available genomic and epigenomic data have expanded dramatically. The MPE approach can also provide a specific risk estimate for each disease subgroup, thereby enhancing the impact of genome-wide association studies on public health. In this article, we present recent progress of MPE, and discuss the importance of accounting for the disease heterogeneity in the era of big-data health science and precision medicine.

Vitamin D and Physical Activity in Patients With Colorectal Cancer: Epidemiological Evidence and Therapeutic Implications

Colorectal cancer (CRC) is a leading cause of cancer incidence and mortality in the United States. Notwithstanding major improvements in the early detection and treatment of CRC, an important proportion of patients who received a diagnosis of localized disease ultimately have a recurrence and die, underscoring the need of new therapeutic approaches. Vitamin D and physical activity (PA) have emerged as 2 potential interventions for both prevention and treatment of CRC. Plausible biological mechanisms have been described for the antineoplastic effects of vitamin D and PA, and a wealth of epidemiological evidence indicates that 25(OH)D (the main circulating form of vitamin D) and PA levels are inversely associated with CRC risk. Recent efforts have now focused on the role of vitamin D and PA as adjunct treatments after a CRC diagnosis. Observational studies evaluating prediagnosis and postdiagnosis circulating 25(OH)D levels among patients with CRC of all stages have found that subjects with levels in the highest quantiles have improved overall and CRC-specific survival compared with those with levels in the lowest quantiles. Similarly, prospective studies of PA have found that higher levels of postdiagnosis PA are associated with lower overall and CRC-specific mortality in patients with nonmetastatic CRC. Meta-analyses of the observational studies of 25(OH)D and postdiagnosis PA have confirmed significant protective associations against overall and CRC-specific mortality, as well as significant dose-response relationships. No randomized controlled trial of vitamin D or PA using survival outcomes as endpoints has been completed to date. Two randomized, placebo-controlled trials of vitamin D in patients with metastatic CRC assessing patient survival as an endpoint are underway: the first is a phase II trial comparing high-dose vitamin D3 (8000 IU/d for 2 weeks followed by 4000 IU/d) versus standard dose (400 IU/d), and the second is a phase I-II trial comparing customized oral doses of vitamin D3 titrated to raise serum 25(OH)D levels to 80 to 100 ng/mL versus 2000 IU/d. For PA, the ongoing phase III CHALLENGE (Colon Health and Life-Long Exercise Change) study is the first randomized controlled trial using survival as an endpoint among patients with stage II-III colon cancer. The results of these trials will pave the way to more conclusive phase III trials that will provide more definitive answers about the role of these interventions in the treatment of CRC. Lastly, the advent of genomic technologies will allow identifying molecular signatures in CRC associated with improved response to vitamin D and PA and will usher in a precision medicine approach to these therapies.

Physical Activity and Cancer Outcomes: A Precision Medicine Approach

There is increasing interest in applying a precision medicine approach to understanding exercise as a potential treatment for cancer. We aimed to inform this new approach by appraising epidemiologic literature relating postdiagnosis physical activity to cancer outcomes overall and by molecular/genetic subgroups. Across 26 studies of breast, colorectal, and prostate cancer patients, a 37% reduction was seen in risk of cancer-specific mortality, comparing the most versus the least active patients (pooled relative risk = 0.63; 95% confidence interval: 0.54-0.73). Risks of recurrence or recurrence/cancer-specific death (combined outcome) were also reduced based on fewer studies. We identified ten studies of associations between physical activity and cancer outcomes by molecular or genetic markers. Two studies showed statistically significant risk reductions in breast cancer mortality/recurrence for the most (versus least) physically active estrogen receptor-positive/progesterone receptor-positive (ER⁺/PR⁺) patients, while others showed risk reductions among ER^-PR^- and triple-negative patients. In colorectal cancer, four studies showed statistically significant risk reductions in cancer-specific mortality for patients with high (versus low) physical activity and P21 expression, P27 expression, nuclear CTNNB1^-, PTGS2 (COX-2)⁺, or IRS1 low/negative status. One prostate cancer study showed effect modification by Gleason score. As a means to enhance this evidence, future observational studies are needed that will measure physical activity objectively before and after diagnosis, use standardized definitions for outcomes, control for competing risks, assess nonlinear dose-response relations, and consider reverse causality. Ultimately, randomized controlled trials with clinical cancer outcomes and a correlative component will provide the best evidence of causality, relating exercise to cancer outcomes, overall and for molecular and genetic subgroups. Clin Cancer Res; 22(19); 4766-75. ©2016 AACR.