Resistance training and the risk of colon and rectal cancers

The Physical Activity and Cancer Control (PACC) framework: update on the evidence, guidelines, and future research priorities

BACKGROUND

We proposed the Physical Activity and Cancer Control (PACC) framework in 2007 to help organise, focus, and stimulate research on physical activity in eight cancer control categories: prevention, detection, treatment preparation/coping, treatment coping/effectiveness, recovery/rehabilitation, disease prevention/health promotion, palliation, and survival.

METHODS

This perspective paper provides a high-level overview of the scientific advances in physical activity research across cancer control categories, summarises current guidelines, updates the PACC framework, identifies remaining and emerging knowledge gaps, and provides future research directions.

RESULTS

Many scientific advances have been made that are reflected in updated physical activity guidelines for six of the cancer control categories apart from detection and palliation. Nevertheless, the minimal and optimal type, dose, and timing of physical activity across cancer control categories remain unknown, especially for the understudied population subgroups defined by cancer type, age, race/ethnicity, and resource level of regions/countries.

CONCLUSION

To achieve the full benefit of physical activity in cancer control, future research should use innovative study designs that include diverse at-risk populations and understudied cancer sites. Additionally, effective behaviour change strategies are needed to increase physical activity levels across populations that use implementation science to accelerate the translation from evidence generation into practical, real-world interventions.

Muscle-strengthening activities and cancer incidence and mortality: a systematic review and meta-analysis of observational studies

Background

Physical activity has been associated with reduced risk of seven types of cancer. It remains unclear, however, whether muscle-strengthening activities also reduce cancer incidence and mortality.

Methods

PubMed, Embase, Web of Science and Scopus were searched from inception to March 2020. Summary hazard ratio (HR) and 95% confidence intervals (CI) were estimated using random-effects models.

Results

Twelve studies (11 cohorts; 1 case-control), 6 to 25 years of follow-up, including 1,297,620 participants, 32,196 cases and 31,939 deaths, met inclusion criteria. Muscle-strengthening activities were associated with a 26% lower incidence of kidney cancer (HR for high vs low levels of muscle-strengthening activities: 0.74; 95% CI 0.56 to 0.98; I² 0%; 2 studies), but not with incidence of other 12 types of cancer. Muscle-strengthening activities were associated with lower total cancer mortality: HRs for high vs low levels of muscle-strengthening activities was 0.87 (95% CI 0.73 to 1.02; I² 58%; 6 studies); and HR for ≥2 times/week vs < 2 times/week of muscle-strengthening activities was 0.81 (95% CI 0.74 to 0.87; I² 0%; 4 studies). Regarding the weekly duration of muscle-strengthening activities, HR for total cancer mortality were 0.91 (95% CI 0.82 to 1.01; I² 0%; 2 studies) for 1–59 min/week and 0.98 (95% CI 0.89 to 1.07; I² 0%) for ≥60 min/week vs none. Combined muscle-strengthening and aerobic activities (vs none) were associated with a 28% lower total cancer mortality (HR 0.72; 95% CI 0.53 to 0.98; I² 85%; 3 studies).

Conclusions

Muscle-strengthening activities were associated with reduced incidence of kidney cancer and total cancer mortality. Combined muscle-strengthening and aerobic activities may provide a greater reduction in total cancer mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01142-7.

The association of resistance training with risk of ovarian cancer

Background

Increasing evidence, including multiple putative inflammatory risk factors (e.g., c‐reactive protein, and adiposity), supports that inflammation plays an important role in ovarian carcinogenesis. Resistance training (RT) is associated with lower levels of circulating inflammatory markers, independent of physical activity.

Methods

We evaluated the relationship between RT and risk of ovarian cancer accounting for other physical activity (e.g., walking) in two large prospective cohorts, the Nurses’ Health Study (NHS) and NHSII.

Key Results

In total, analyses included 42,005 NHS participants (2000–2016) and 67,289 NHSII participants (2001–2017) with RT assessed every 4 years. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of RT with ovarian cancer risk overall and by tumor subtype, adjusting for known and putative ovarian cancer risk factors. We identified a total of 609 cases over 1,748,884 person‐years. No association was observed with overall ovarian cancer risk (RT ≥60 vs 0 min/wk, HR = 0.95, 95%CI: 0.74–1.22) or by histotype (comparable HR = 0.86 and 0.98 for type I and II tumors, respectively). Results did not differ by body mass index (Pinteraction = 0.97), or other physical activity (Pinteraction = 0.31).

Conclusions & Inferences

We observed no evidence that moderate levels of RT were associated with risk of ovarian cancer. Further investigations are required to confirm these findings.

Association between physical activity and digestive-system cancer: An updated systematic review and meta-analysis

BACKGROUND

Physical activity (PA) may have an impact on digestive-system cancer (DSC) by improving insulin sensitivity and anticancer immune function and by reducing the exposure of the digestive tract to carcinogens by stimulating gastrointestinal motility, thus reducing transit time. The current study aimed to determine the effect of PA on different types of DSC via a systematic review and meta-analysis.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched for relevant studies in PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure. Using a random effects model, the relationship between PA and different types of DSC was analyzed.

RESULTS

The data used for meta-analysis were derived from 161 risk estimates in 47 studies involving 5,797,768 participants and 55,162 cases. We assessed the pooled associations between high vs. low PA levels and the risk of DSC (risk ratio (RR)  = 0.82, 95% confidence interval (95%CI): 0.79-0.85), colon cancer (RR = 0.81, 95%CI: 0.76-0.87), rectal cancer (RR = 0.88, 95%CI: 0.80-0.98), colorectal cancer (RR = 0.77, 95%CI: 0.69-0.85), gallbladder cancer (RR = 0.79, 95%CI: 0.64-0.98), gastric cancer (RR = 0.83, 95%CI: 0.76-0.91), liver cancer (RR = 0.73, 0.60-0.89), oropharyngeal cancer (RR = 0.79, 95%CI: 0.72-0.87), and pancreatic cancer (RR = 0.85, 95%CI: 0.78-0.93). The findings were comparable between case-control studies (RR = 0.73, 95%CI: 0.68-0.78) and prospective cohort studies (RR = 0.88, 95%CI: 0.80-0.91). The meta-analysis of 9 studies reporting low, moderate, and high PA levels, with 17 risk estimates, showed that compared to low PA, moderate PA may also reduce the risk of DSC (RR = 0.89, 95%CI: 0.80-1.00), while compared to moderate PA, high PA seemed to slightly increase the risk of DSC, although the results were not statistically significant (RR = 1.11, 95%CI: 0.94-1.32). In addition, limited evidence from 5 studies suggested that meeting the international PA guidelines might not significantly reduce the risk of DSC (RR = 0.96, 95%CI: 0.91-1.02).

CONCLUSION

Compared to previous research, this systematic review has provided more comprehensive information about the inverse relationship between PA and DSC risk. The updated evidence from the current meta-analysis indicates that a moderate-to-high PA level is a common protective factor that can significantly lower the overall risk of DSC. However, the reduction rate for specific cancers may vary. In addition, limited evidence suggests that meeting the international PA guidelines might not significantly reduce the risk of DSC. Thus, future studies must be conducted to determine the optimal dosage, frequency, intensity, and duration of PA required to reduce DSC risk effectively.

Weight Training and Risk of 10 Common Types of Cancer

INTRODUCTION

Ample data support that leisure time aerobic moderate to vigorous physical activity (MVPA) is associated with lower risk of at least seven types of cancer. However, the link between muscle-strengthening activities and cancer etiology is not well understood. Our objective was to determine the association of weight lifting with incidence of 10 common cancer types.

METHODS

We used multivariable Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for association of weight lifting with incidence of 10 cancer types in the National Institutes of Health-American Association of Retired Persons Diet and Health Study follow-up. Weight lifting was modeled continuously and categorically. Dose-response relationships were evaluated using cubic restricted spline models. We explored whether associations varied by subgroups defined by sex, age, and body mass index using the Wald test for homogeneity. We examined joint categories of MVPA and weight lifting in relation to cancer risk for significant associations.

RESULTS

After adjusting for all covariates including MVPA, we observed a statistically significant lower risk of colon cancer (Ptrend = 0.003) in individuals who weight lifted; the HR and 95% CI associated with low and high weight lifting as compared with no weight lifting were 0.75 (95% CI, 0.66-0.87) and 0.78 (95% CI, 0.61-0.98), respectively. The weight lifting-colon cancer relationship differed between men and women (any weight lifting vs no weight lifting: HRmen = 0.91; 95% CI, 0.84-0.98; HRwomen = 1.00; 95% CI, 0.93-1.08; Pinteraction = 0.008). A lower risk of kidney cancer among weight lifters was observed but became nonsignificant after adjusting for MVPA (Ptrend = 0.06), resulting in an HR of 0.94 (95% CI, 0.78-1.12) for low weight lifting and 0.80 (95% CI, 0.59-1.11) for high weight lifting.

CONCLUSIONS

Participants who engaged in weight lifting had a significantly lower risk of colon cancer and a trend toward a lower risk of kidney cancer than participants who did not weight lift.

Lifetime recreational physical activity and the risk of prostate cancer

PURPOSE

Research on the association between physical activity and the risk of prostate cancer is inconsistent. The aim of this study was to investigate whether the timing, intensity, and type of recreational physical activity influence prostate cancer risk.

METHODS

A population-based case-control study was conducted in Western Australia in 2001-2002. Data were collected on lifetime recreational physical activity from a self-reported questionnaire. The estimated effects of recreational physical activity on prostate cancer risk were analyzed using logistic regression, adjusting for demographic and lifestyle factors. This analysis included 569 incident cases and 443 controls.

RESULTS

There was a significant, inverse dose-response relationship between vigorous-intensity recreational physical activity between the ages 19 and 34 years and the risk of prostate cancer (p_Trend = 0.013). Participants in the most active quartile of vigorous-intensity physical activity in this age period had a 33% lower risk of prostate cancer than participants in the least active quartile (Adjusted Odds Ratio = 0.67, 95% confidence interval = 0.45-1.01). Moderate-intensity recreational physical activity was not associated with the risk of prostate cancer. Recreational physical activity performed over the lifetime showed no association with prostate cancer risk. Weight training performed from early adulthood onwards showed a non-significant but consistent inverse association with prostate cancer risk. There was no strong evidence that physical activity was differentially associated with the risks of low-grade and medium-to-high grade prostate cancers.

CONCLUSIONS

A high level of vigorous recreational physical activity in early adulthood may be required to reduce the risk of prostate cancer.

Physical Activity and Gastrointestinal Cancer Risk: A Review

Introduction: Western lifestyle characterized by increased consumption of red meat, fat, processed food, smoking, alcohol drinking, lower consumption of vegetables and physical inactivity has been associated with a higher gastrointestinal cancer risk. Digestive system cancers are diagnosed at late stages when they show poor response to treatment and are associated with a high mortality rate. Colorectal, gastric, esophageal and pancreatic cancers are among the most common cancers worldwide. Studies show that more than 50% of gastrointestinal cancers develop as a result of inappropriate lifestyle. An inverse association between physical activity and many chronic diseases has been proved so far. However, the association between physical activity and some gastrointestinal cancers is still controversial. This study was aimed to determine the association between physical activity and gastrointestinal cancers risk.

Methods: We conducted a comprehensive search of English and Persian databases from February 2007 till December 2017, for studies investigating the association of physical activity and risk of gastrointestinal cancers. Finally, after reading full text of articles, 123 studies were included.

Results: Physical activity can be helpful in reducing the risk of gastrointestinal cancer, especially colon and pancreatic cancers. The risk reduction is not similar for different types of gastrointestinal cancers and also among males and females.

Conclusion: Different types of physical activity are associated with a lower risk of gastrointestinal cancer. However, it is unknown which type and intensity of physical activity are associated with a protective effect against gastro-intestinal cancer.

Effects of physical activity on colorectal cancer risk among family history and body mass index subgroups: a systematic review and meta-analysis

Background

Physical activity is consistently associated with a reduced risk of colorectal cancer in epidemiologic studies. This association among higher risk subgroups, such as those with a first-degree family history of colorectal cancer or high body mass index remains unclear.

Methods

We searched MEDLINE for studies examining physical activity and colorectal cancer risk among higher risk subgroups through July 11, 2017. Fifteen and three studies were eligible for inclusion for body mass index and first-degree family history of colorectal cancer subgroups, respectively. Estimates of the highest to lowest comparison of physical activity for each subgroup of risk were pooled using random-effects models.

Results

The pooled associations of physical activity and colorectal cancer risk for those without and with a first-degree family history of colorectal cancer were 0.56 (95% confidence interval (CI) = 0.39–0.80) and 0.72 (95% CI = 0.39–1.32), respectively (p_{heterogeneity} = 0.586). The pooled associations of physical activity and colorectal cancer risk for the low and high body mass index groups were 0.74 (95% CI = 0.66–0.83) and 0.65 (95% CI = 0.53–0.79), respectively (p_{heterogeneity} = 0.389).

Conclusions

Overall, a stronger relative risk of physical activity on colorectal cancer risk was observed in the higher body mass index group, although the difference was not statistically significant, suggesting an added benefit of physical activity as a cancer prevention strategy in population groups with strong risk factors for colorectal cancer. Additional research among these subgroups is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3970-5) contains supplementary material, which is available to authorized users.

Current nutrition promotion, beliefs and barriers among cancer nurses in Australia and New Zealand

Rationale. Many cancer patients and survivors do not meet nutritional and physical activity guidelines, thus healthier eating and greater levels of physical activity could have considerable benefits for these individuals. While research has investigated cancer survivors’ perspective on their challenges in meeting the nutrition and physical guidelines, little research has examined how health professionals may assist their patients meet these guidelines. Cancer nurses are ideally placed to promote healthy behaviours to their patients, especially if access to dieticians or dietary resources is limited. However, little is known about cancer nurses’ healthy eating promotion practices to their patients. The primary aim of this study was to examine current healthy eating promotion practices, beliefs and barriers of cancer nurses in Australia and New Zealand. A secondary aim was to gain insight into whether these practices, beliefs and barriers were influenced by the nurses’ hospital or years of work experience.

Patients and Methods. An online questionnaire was used to obtain data. Sub-group cancer nurse comparisons were performed on hospital location (metropolitan vs regional and rural) and years of experience (<25 or ≥25 years) using ANOVA and chi square analysis for continuous and categorical data respectively.

Results. A total of 123 Australasian cancer nurses responded to the survey. Cancer nurses believed they were often the major provider of nutritional advice to their cancer patients (32.5%), a value marginally less than dieticians (35.9%) but substantially higher than oncologists (3.3%). The majority promoted healthy eating prior (62.6%), during (74.8%) and post treatment (64.2%). Most cancer nurses felt that healthy eating had positive effects on the cancer patients’ quality of life (85.4%), weight management (82.9%), mental health (80.5%), activities of daily living (79.7%) and risk of other chronic diseases (79.7%), although only 75.5% agreed or strongly agreed that this is due to a strong evidence base. Lack of time (25.8%), adequate support structures (17.3%) nutrition expertise (12.2%) were cited by the cancer nurses as the most common barriers to promoting healthy eating to their patients. Comparisons based on their hospital location and years of experience, revealed very few significant differences, indicating that cancer nurses’ healthy eating promotion practices, beliefs and barriers were largely unaffected by hospital location or years of experience.

Conclusion. Australasian cancer nurses have favourable attitudes towards promoting healthy eating to their cancer patients across multiple treatment stages and believe that healthy eating has many benefits for their patients. Unfortunately, several barriers to healthy eating promotion were reported. If these barriers can be overcome, nurses may be able to work more effectively with dieticians to improve the outcomes for cancer patients.

Exploring opportunities for colorectal cancer screening and prevention in the context of diabetes self-management: an analysis of the 2010 National Health Interview Survey

Because diabetes is associated with increased colorectal cancer (CRC) risk, it is important that people with diabetes receive CRC screenings according to guidelines. In addition, many diabetes self-care recommendations are associated with a reduced risk of CRC. This study aims to identify potential opportunities for enhancing CRC prevention within the context of diabetes management. Using data from 1,730 adults with diabetes aged 50-75 years who responded to the 2010 National Health Interview Survey, we calculated population estimates of behaviors consistent with US Preventive Services Task Force guidelines for CRC screening and American Diabetes Association recommendations for diabetes care. We examined bivariate associations between CRC screening and selected diabetes self-care behaviors associated with CRC risk. Results were stratified by demographic characteristics. Thirty-nine percent of adults with diagnosed diabetes were not up-to-date with CRC screenings. Sixteen percent smoked and 2 % exceeded alcohol intake recommendations. Among those capable of exercise, 69 and 90 % did not meet aerobic exercise and resistance training recommendations, respectively. CRC screening was generally not associated with diabetes self-care behaviors. Among some demographic groups, CRC screening was associated with adequate aerobic activity, not smoking, and being overweight or obese. Many adults with diabetes do not follow guidelines for CRC screening or recommendations for diabetes care that may also reduce CRC risk. Thus, opportunities may exist to jointly promote CRC screening and prevention and diabetes self-management among adults with diabetes.

Lifestyle factors associated with survival after colorectal cancer diagnosis

Background:

Aside from tumour stage and treatment, little is known about potential factors that may influence survival in colorectal cancer patients. The aim of this study was to investigate the associations between physical activity, obesity and smoking and disease-specific and overall mortality after a colorectal cancer diagnosis.

Methods:

A cohort of 879 colorectal cancer patients, diagnosed in Western Australia between 2005 and 2007, were followed up to 30 June 2012. Cox's regression models were used to estimate the hazard ratios (HR) for colorectal cancer-specific and overall mortality associated with self-reported pre-diagnosis physical activity, body mass index (BMI) and smoking.

Results:

Significantly lower overall and colorectal cancer-specific mortality was seen in females who reported any level of recent physical activity than in females reporting no activity. The colorectal cancer-specific mortality HR for increasing levels of physical activity in females were 0.34 (95% CI=0.15, 0.75), 0.37 (95% CI=0.17, 0.81) and 0.41 (95% CI=0.18, 0.90). Overweight and obese women had almost twice the risk of dying from any cause or colorectal cancer compared with women of normal weight. Females who were current smokers had worse overall and colorectal cancer-specific mortality than never smokers (overall HR=2.64, 95% CI=1.18, 5.93; colorectal cancer-specific HR=2.70, 95% CI=1.16, 6.29). No significant associations were found in males.

Conclusion:

Physical activity, BMI and smoking may influence survival after a diagnosis of colorectal cancer, with more pronounced results found for females than for males.