Recreational physical activity, body mass index, and survival in women with colorectal cancer

Longitudinal, observational study on associations between postoperative nutritional vitamin D supplementation and clinical outcomes in esophageal cancer patients undergoing esophagectomy

Vitamin D can exert anticancer effect beyond bone and calcium metabolism. We aimed to investigate whether postoperative vitamin D supplementation affects quality of life (QOL) and survival in esophageal cancer (EC) patients. We utilized the widely used EORTC QLQ-C30 and QLQ-OES18 to assess QOL at EC diagnosis and 24 months after surgery. Generalized estimating equations (GEEs) were used to analysis the association of vitamin D supplement use with QOL. Kaplan-Meier method and Cox regression model were used to evaluate the prognostic value of vitamin D supplementation. The notably improved QOL were found among vitamin D supplementation users compared with non-users (p < 0.05). Kaplan-Meier analysis revealed that vitamin D supplement use was significantly associated with improved disease-free survival (DFS) (p = 0.030), but not related to overall survival (OS) (p = 0.303). The multivariable analysis further demonstrated vitamin D supplement use as an independent prognostic factor for DFS (p = 0.040; HR 0.610; 95% CI 0.381-0.978). In conclusion, these results showed that vitamin D supplement use could serve as a promising intervention to enhancing QOL and prolonging DFS in EC.

Physical activity and sedentary behavior in relation to lung cancer incidence and mortality in older women: The Women's Health Initiative

Physical activity has been associated with lower lung cancer incidence and mortality in several populations. We investigated these relationships in the Women's Health Initiative Observational Study (WHI-OS) and Clinical Trial (WHI-CT) prospective cohort of postmenopausal women. The WHI study enrolled 161,808 women aged 50-79 years between 1993 and 1998 at 40 U.S. clinical centers; 129,401 were eligible for these analyses. Cox proportional hazards models were used to assess the association of baseline physical activity levels [metabolic equivalent (MET)-min/week: none <100 (reference), low 100 to <500, medium 500 to <1,200, high 1,200+] and sedentary behavior with total lung cancer incidence and mortality. Over 11.8 mean follow-up years, 2,148 incident lung cancer cases and 1,365 lung cancer deaths were identified. Compared with no activity, higher physical activity levels at study entry were associated with lower lung cancer incidence [p = 0.009; hazard ratios (95% confidence intervals) for each physical activity category: low, HR: 0.86 (0.76-0.96); medium, HR: 0.82 (0.73-0.93); and high, HR: 0.90 (0.79-1.03)], and mortality [p < 0.0001; low, HR: 0.80 (0.69-0.92); medium, HR: 0.68 (0.59-0.80); and high, HR: 0.78 (0.66-0.93)]. Body mass index (BMI) modified the association with lung cancer incidence (p = 0.01), with a stronger association in women with BMI < 30 kg/m(2) . Significant associations with sedentary behavior were not observed. In analyses by lung cancer subtype, higher total physical activity levels were associated with lower lung cancer mortality for both overall NSCLC and adenocarcinoma. In conclusion, physical activity may be protective for lung cancer incidence and mortality in postmenopausal women, particularly in non-obese women.

Up-regulation of REG3A in colorectal cancer cells confers proliferation and correlates with colorectal cancer risk

Colorectal cancer (CRC) is one of the most common malignancies in the world. Previous studies have investigated the altered expression of regenerating islet-derived 3 alpha (REG3A) in various cancers. We aimed at exploring the biological function and the underlying molecular mechanism of REG3A in CRC. In this study, REG3A was found elevated in CRC compared with normal tissues. Further, high REG3A expression level was correlated with bigger tumor size, poorer differentiation, higher tumor stage and lower survival rate. Knockdown of REG3A in two CRC cell lines, LOVO and RKO, significantly inhibited cell proliferation, and increased cells population in G1 phase and cell apoptotic rate. We also found that down-regulation of REG3A in CRC cells notably inhibited cell migration and invasion. Gene set enrichment analysis on The Cancer Genome Atlas dataset showed that Kyoto Encyclopedia of Genes and Genomes (KEGG) DNA replication and base excision repair (BER) pathways were correlative with the REG3A expression, which was further confirmed in CRC cells by Western blot. Moreover, we confirmed the interaction of REG3A and fibronectin in CRC cells. We also found that there was a positive correlation between REG3A expression level and the AKT and ERK1/2 phosphorylation status. These collective data indicated that REG3A overexpression promotes CRC tumorigenesis by activating AKT and ERK1/2 pathways. REG3A may serve as a promising therapeutic strategy for CRC.

Prediagnosis body mass index and waist-hip circumference ratio in association with colorectal cancer survival

The association of obesity on survival among patients with colorectal cancer (CRC) has not been well characterized. We investigated the association of prediagnostic body mass index (BMI)/waist-hip ratio (WHR) and total/cause-specific mortality in CRC patients. Our study included 1,452 patients who participated in two large cohort studies and were diagnosed with CRC during follow-up period. Participants were measured for anthropometrics and interviewed to collect relevant information at baseline, prior to any cancer diagnosis. Data on site-specific cancer incidence and cause-specific mortality were obtained via in-person surveys and annual record linkage with cancer and vital statistics registries. Cox proportional hazard models were used to evaluate the associations of BMI and WHR with survival. A total of 547 participants died during the follow-up period, including 499 who died of CRC. Relative to normal BMI (18.5 to <25.0 kg/m² ), obesity (BMI ≥ 30 kg/m² ) was associated with increased mortality resulting from all causes [hazard ratio (HR) = 1.5, 95% confidence interval (CI): 1.1-2.1] and CRC (HR = 1.5, 95% CI: 1.1-2.1). Elevated risk of death was also found among underweight patients (BMI < 18.5 kg/m² ), although not all risk estimates were statistically significant. Overweight BMI (25.0 to <30.0 kg/m² ) was not associated with risk of death among CRC patients, nor was WHR. In conclusion, prediagnostic BMI was associated with survival among CRC patients following a U-shape pattern; obesity was associated with high mortality after CRC diagnosis. These findings provide support for maintaining healthy weight to improve the survival of CRC patients.

Metabolic Dysfunction, Obesity, and Survival Among Patients With Early-Stage Colorectal Cancer

PURPOSE

The effects of obesity and metabolic dysregulation on cancer survival are inconsistent. To identify high-risk subgroups of obese patients and to examine the joint association of metabolic syndrome (MetSyn) in combination with obesity, we categorized patients with early-stage (I to III) colorectal cancer (CRC) into four metabolic categories defined by the presence of MetSyn and/or obesity and examined associations with survival.

METHODS

We studied 2,446 patients diagnosed from 2006 to 2011 at Kaiser Permanente. We assumed MetSyn if patients had three or more of five components present at diagnosis: fasting glucose > 100 mg/dL or diabetes; elevated blood pressure (systolic ≥ 130 mm Hg, diastolic ≥ 85 mm Hg, or antihypertensives); HDL cholesterol < 40 mg/dL (men) or < 50 mg/dL (women); triglycerides ≥ 150 mg/dL or antilipids; and/or highest sex-specific quartile of visceral fat by computed tomography scan (in lieu of waist circumference). We then classified participants according to the presence (or absence) of MetSyn and obesity (BMI < 30 or ≥ 30 kg/m²) and assessed associations with overall and CRC-related survival using Cox proportional hazards models adjusted for demographic, tumor, and treatment factors and muscle mass at diagnosis.

RESULTS

Over a median follow-up of 6 years, 601 patients died, 325 as a result of CRC. Mean (SD) age was 64 (11) years. Compared with the reference of nonobese patients without MetSyn (n = 1,225), for overall survival the hazard ratios (HR) and 95% CIs were 1.45 (1.12 to 1.82) for obese patients with MetSyn (n = 480); 1.09 (0.83 to 1.44) for the nonobese with MetSyn (n = 417), and 1.00 (0.80 to 1.26) for obese patients without MetSyn (n = 324). Obesity with MetSyn also predicted CRC-related survival: 1.49 (1.09 to 2.02). The hazard of death increased with the number of MetSyn components present, independent of obesity.

CONCLUSION

Patients with early-stage CRC with obesity and MetSyn have worse survival, overall and CRC related.

Relationship of prediagnostic body mass index with survival after colorectal cancer: Stage-specific associations

Higher body mass index (BMI) is a well-established risk factor for colorectal cancer (CRC), but is inconsistently associated with CRC survival. In 6 prospective studies participating in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), 2,249 non-Hispanic white CRC cases were followed for a median 4.5 years after diagnosis, during which 777 died, 554 from CRC-related causes. Associations between prediagnosis BMI and survival (overall and CRC-specific) were evaluated using Cox regression models adjusted for age at diagnosis, sex, study and smoking status (current/former/never). The association between BMI category and CRC survival varied by cancer stage at diagnosis (I-IV) for both all-cause (p-interaction = 0.03) and CRC-specific mortality (p-interaction = 0.04). Compared to normal BMI (18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9) was associated with increased mortality among those with Stage I disease, and decreased mortality among those with Stages II-IV disease. Similarly, obesity (BMI ≥30) was associated with increased mortality among those with Stages I-II disease, and decreased mortality among those with Stages III-IV disease. These results suggest the relationship between BMI and survival after CRC diagnosis differs by stage at diagnosis, and may emphasize the importance of adequate metabolic reserves for colorectal cancer survival in patients with late-stage disease.

The use of cardiac rehabilitation services to aid the recovery of patients with bowel cancer: a pilot randomised controlled trial with embedded feasibility study

Background

Colorectal cancer (CRC) survivors are not meeting the recommended physical activity levels associated with improving their chances of survival and quality of life. Rehabilitation could address this problem.

Objectives

The aims of the Cardiac Rehabilitation In Bowel cancer study were to assess whether or not cardiac rehabilitation is a feasible and acceptable model to aid the recovery of people with CRC and to test the feasibility and acceptability of the protocol design.

Design

Intervention testing and feasibility work (phase 1) and a pilot randomised controlled trial with embedded qualitative study (phase 2), supplemented with an economic evaluation. Randomisation was to cardiac rehabilitation or usual care. Outcomes were differences in objective measures of physical activity and sedentary behaviour, self-reported measures of quality of life, anxiety, depression and fatigue. Qualitative work involved patients and clinicians from both cancer and cardiac specialties.

Setting

Three colorectal cancer wards and three cardiac rehabilitation facilities.

Participants

Inclusion criteria were those who were aged > 18 years, had primary CRC and were post surgery.

Results

Phase 1 (single site) – of 34 patient admissions, 24 (70%) were eligible and 4 (17%) participated in cardiac rehabilitation. Sixteen clinicians participated in an interview/focus group. Modifications to trial procedures were made for further testing in phase 2. Additionally, 20 clinicians in all three sites were trained in cancer and exercise, rating it as excellent. Phase 2 (three sites) – screening, eligibility, consent and retention rates were 156 (79%), 133 (67%), 41 (31%) and 38 (93%), respectively. Questionnaire completion rates were 40 (97.5%), 31 (75%) and 25 (61%) at baseline, follow-up 1 and follow-up 2, respectively. Forty (69%) accelerometer data sets were analysed; 20 (31%) were removed owing to invalid data.

Qualitative study

CRC and cardiac patients and clinicians were interviewed. Key themes were benefits and barriers for people with CRC attending cardiac rehabilitation; generic versus disease-specific rehabilitation; key concerns of the intervention; and barriers to participation (CRC participants only).

Economic evaluation

The average out-of-pocket expenses of attending cardiac rehabilitation were £50. The costs of cardiac rehabilitation for people with cancer are highly dependent on whether it involves accommodating additional patients in an already existing service or setting up a completely new service.

Limitations and conclusions

The main limitation is that this is a small feasibility and pilot study. The main novel finding is that cardiac rehabilitation for cancer and cardiac patients together is feasible and acceptable, thereby challenging disease-specific rehabilitation models.

Future work

This study highlighted important challenges to doing a full-scale trial of cardiac rehabilitation but does not, we believe, provide sufficient evidence to reject the possibility of such a future trial. We recommend that any future trial must specifically address the challenges identified in this study, such as suboptimal consent, completion, missing data and intervention adherence rates and recruitment bias, and that an internal pilot trial be conducted. This should have clear ‘stop–proceed’ rules that are formally reviewed before proceeding to the full-scale trial.

Trial registration

Current Controlled Trials ISRCTN63510637.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full inHealth Services and Delivery Research; Vol. 4, No. 24. See the NIHR Journals Library website for further project information.

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.

Pre-diagnostic body mass index and weight change in relation to colorectal cancer survival among incident cases from a population-based cohort study

Background

Whether excess body weight influences colorectal cancer (CRC) survival is unclear. We studied pre-diagnostic body mass index (BMI) and weight change in relation to CRC-specific mortality among incident CRC cases within a large, Norwegian cohort.

Methods

Participants’ weight was measured at health examinations up to three times between 1974 and 1988. CRC cases were identified through linkage with the Norwegian Cancer Registry. In total, 1336 men and 1180 women with a weight measurement >3 years prior to diagnosis were included in analyses. Hazard ratios (HRs) and confidence intervals (CIs) were estimated with Cox regression.

Results

During a mean follow-up of 5.8 years, 507 men and 432 women died from CRC. Obesity (BMI ≥30 kg/m²) was associated with higher CRC-specific mortality than normal weight (BMI 18.5–25 kg/m²) in men with proximal colon cancer, HR = 1.85 (95 % CI 1.08–3.16) and in women with rectal cancer, HR = 1.93 (95 % CI 1.13–3.30). Weight gain was associated with higher CRC-specific mortality in women with CRC, colon cancer, and distal colon cancer, HRs per 5 kg weight gain were 1.18 (95 % CI 1.01–1.37), 1.22 (95 % CI 1.02–1.45), and 1.40 (95 % CI 1.01–1.95), respectively. Weight gain was not significantly associated with survival in men.

Conclusions

Maintaining a healthy weight may benefit CRC survival, at least in women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2445-4) contains supplementary material, which is available to authorized users.

Body mass index and colorectal cancer prognosis: a systematic review and meta-analysis

Colorectal cancer is one of the most common cancers worldwide. However, it is unclear what influence body mass index (BMI) has on colorectal cancer prognosis. We conducted a systematic review and meta-analysis of observational studies to examine the association of BMI with colorectal cancer outcomes. We searched MEDLINE and EMBASE databases from inception to February 2015 and references of identified articles. We selected observational studies that reported all-cause mortality, colorectal cancer-specific mortality, recurrence and disease-free survival according to BMI category. Random-effects meta-analyses were conducted to combine estimates. We included 18 observational studies. Obese patients had an increased risk of all-cause mortality [relative risk (RR) 1.14; 95 % confidence interval (CI) 1.07-1.21], cancer-specific mortality (RR 1.14; 95 % CI 1.05-1.24), recurrence (RR 1.07; 95 % CI 1.02-1.13) and worse disease-free survival (RR 1.07; 95 % CI 1.01-1.13). Underweight patients also had an increased risk of all-cause mortality (RR 1.43; 95 % CI 1.26-1.62), cancer-specific mortality (RR 1.50; 95 % CI 1.20-1.87), recurrence (RR 1.13; 95 % CI 1.05-1.21) and worse disease-free survival (RR 1.27; 95 % CI 1.13-1.43). Overweight patients had no increased risk for any of the outcomes studied. Both obese and underweight patients with colorectal cancer have an increased risk of all-cause mortality, cancer-specific mortality, disease recurrence and worse disease-free survival compared to normal weight patients.

Physical Activity and Nutrition in Primary and Tertiary Prevention of Colorectal Cancer

BACKGROUND

Lifestyle factors play a pivotal role in the primary and tertiary prevention of colorectal cancer. The purpose of this review article is to summarize data concerning the effect of the lifestyle factors physical activity (PA) and nutrition in primary and, more importantly, tertiary prevention of colorectal cancer (CRC).

METHODS

Focusing on the influence of lifestyle factors on prognosis und quality of life (QOL), a comprehensive literature search of clinical studies published mainly in the years 2000 until 2015 was performed and the current knowledge based on these clinical studies reviewed.

RESULTS

Besides avoiding risk factors (such as smoking and overindulgence in alcohol), healthy weight, regular and moderate PA as well as a diet which contains fruit, vegetables, poultry, and fish (so-called 'Mediterranean' diet) may reduce the risk of the disease significantly. Patients already diagnosed with CRC can also actively improve the prognosis of CRC and QOL by changing their lifestyle. Patients commencing moderate exercise and modifying their eating habits in terms of a 'Mediterranean' diet can reduce cancer-specific and overall mortality by up to 40% and significantly increase their quality of life already during chemotherapy. Therefore, moderate physical exercise, calorie restriction, and a Mediterranean dietary pattern for patients with CRC should be recommended by physicians treating these patients. In fact, the World Cancer Research Fund/American Institute for Cancer Research (AICR/WCRF) systematic literature review from 2007 shows that the lifestyle changes recommended after diagnosis are the same for primary prevention of this disease.

CONCLUSION

Lifestyle changes such as moderate PA and a Mediterranean diet significantly improve the QOL as well as the prognosis of patients suffering from colorectal disease. However, the effect of lifestyle changes is mostly based on observational studies, while only few studies are prospective and none are randomized. Therefore, these observational studies warrant controlled randomized trials to prove the effectiveness of lifestyle interventions on QOL and cancer recurrence.

A randomized phase II dose-response exercise trial among colon cancer survivors: Purpose, study design, methods, and recruitment results

BACKGROUND

Observational studies indicate that higher volumes of physical activity are associated with improved disease outcomes among colon cancer survivors. The aim of this report is to describe the purpose, study design, methods, and recruitment results of the courage trial, a National Cancer Institute (NCI) sponsored, phase II, randomized, dose-response exercise trial among colon cancer survivors.

METHODS/RESULTS

The primary objective of the courage trial is to quantify the feasibility, safety, and physiologic effects of low-dose (150 min·week(-1)) and high-dose (300 min·week(-1)) moderate-intensity aerobic exercise compared to usual-care control group over six months. The exercise groups are provided with in-home treadmills and heart rate monitors. Between January and July 2015, 1433 letters were mailed using a population-based state cancer registry; 126 colon cancer survivors inquired about participation, and 39 were randomized onto the study protocol. Age was associated with inquiry about study participation (P<0.001) and randomization onto the study protocol (P<0.001). No other demographic, clinical, or geographic characteristics were associated with study inquiry or randomization. The final trial participant was randomized in August 2015. Six month endpoint data collection was completed in February 2016.

DISCUSSION

The recruitment of colon cancer survivors into an exercise trial is feasible. The findings from this trial will inform key design aspects for future phase 2 and phase 3 randomized controlled trials to examine the efficacy of exercise to improve clinical outcomes among colon cancer survivors.

Cardiopulmonary fitness, adiponectin, chemerin associated fasting insulin level in colorectal cancer patients

PURPOSE

Since circulating level of insulin is associated with colorectal cancer prognosis, it is important to identify factors contributing to fasting insulin level in colorectal cancer patients. The purpose of the current study is to investigate the association of physical fitness, adiponectin, and chemerin levels with circulating level of insulin in colorectal cancer patients.

METHODS

A total of 123 stage II-III colorectal cancer patients who completed standard cancer treatment were recruited. Anthropometric characteristics, fitness measurements, fasting insulin level, homeostasis model assessment of insulin resistance, lipid profiles, and adiponectin and chemerin levels were analyzed.

RESULT

Cardiopulmonary fitness level inversely associated with fasting insulin levels (the least fit (1st tertile): 8.11 ± 0.64, moderately fit (2nd tertile): 6.02 ± 0.63, and highly fit (3rd tertile): 5.58 ± 0.66 μU/ml, unfit vs. moderately fit, p < 0.01; unfit vs. highly fit, p < 0.05) after adjustment for gender, age, stage, and BMI. In addition, fasting adiponectin and chemerin levels were associated with fasting insulin levels after adjustment for gender, age, stage, and BMI. In our combined analyses, participants with high adiponectin and low chemerin levels showed significantly lower fasting insulin levels (4.92 ± 0.75 vs. 8.07 ± 0.80 μU/ml, p < 0.01) compared with participants with low adiponectin and high chemerin levels. Multiple linear regression analysis confirmed that cardiopulmonary fitness and adiponectin levels (β = -0.299, p = 0.002; β = -0.201, p = 0.033) were independently associated with fasting insulin level.

CONCLUSION

Our results suggest that physical fitness and adiponectin and chemerin levels may contribute to circulating levels of insulin. These results suggest that exercise may influence the prognosis of colorectal cancer patients by influencing physical fitness level, circulating levels of adiponectin and chemerin.

Severe obesity prior to diagnosis limits survival in colorectal cancer patients evaluated at a large cancer centre

Background:

In contrast to the consistent evidence for obesity and colorectal cancer (CRC) risk, the impact of obesity in CRC patients is less clear. In a well-characterised cohort of CRC patients, we prospectively evaluated class I and class II obesity with survival outcomes.

Methods:

The CRC patients (N=634) were followed from the date of diagnosis until disease progression/first recurrence (progression-free survival (PFS)) or death (overall survival (OS)). Body mass index (BMI) was calculated from reported usual weight prior to diagnosis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated in models adjusted for clinicopathologic, treatment, and lifestyle factors.

Results:

Over a median follow-up of 4 years, 208 (33%) patients died and 235 (37%) recurred or progressed. Class II obesity, as compared with either overweight or normal weight, was associated with an increased risk of death (HR and 95% CI: 1.55 (0.97–2.48) and 1.65 (1.02–2.68), respectively), but no clear association was observed with PFS. In analyses restricted to patients who presented as stages I–III, who reported stable weight, or who were aged <50 years, obesity was associated with a significant two- to five-fold increased risk of death.

Conclusions:

In CRC patients evaluated at a large cancer centre, severely obese patients experienced worse survival outcomes independent of many other factors.

Surveillance and Survivorship after Treatment for Colon Cancer

Colorectal cancer is the third most common cancer diagnosed in the United States. Majority of patients have localized disease that is amenable to curative resection. Disease recurrence remains a major concern after resection. In addition, patients are at an increased risk for developing a second or metachronous colon cancer. The principal goal of surveillance following treatment of colon cancer is to improve disease-free and overall survival. Survivorship is a distinct phase following surveillance to help improve quality of life and promote longevity.

Physical activity communication between oncology providers and patients with early-stage breast, colon, or prostate cancer

BACKGROUND

National guidelines recommend that patients with a cancer diagnosis engage in regular physical activity to reduce cancer-related fatigue, maintain quality of life and physical function, and improve overall prognosis and survival. This study investigates oncology provider communications about physical activity during routine clinic visits with patients with early-stage breast, colon, or prostate cancer.

METHODS

This study used a retrospective chart review for documentation of inquiries or recommendations pertaining to physical activity in clinician notes and after-visit patient summaries.

RESULTS

In a 1-month period, 55 oncology providers had 361 encounters (clinic visits) with early-stage cancer patients. Thirty-five percent of these encounters included a provider communication about "physical activity," "exercise," or "activity." Encounters with a medical oncologist resulted in a physical activity communication 55% of the time, whereas encounters with other clinician specialties did so 20% of the time (P < .0001). The likelihood of a physical activity communication increased with patient age (P < .001). When the encounter was with a patient who was being seen for surveillance, chemotherapy, or endocrine treatment, the rate of physical activity communications was significantly higher (46%, 37%, and 58%, respectively) than the rate when the visit was during radiation treatment or surgery (6% and 19%, respectively; P < .0001).

CONCLUSIONS

This study shows that it is feasible for oncology providers to have physical activity communications during routine clinic visits; however, the frequency of physical activity communications varies among providers. Interventions are needed to remind and encourage all oncology providers to encourage their patients with early-stage cancer to be physically active. .

Excess body weight and colorectal cancer survival: the multiethnic cohort

PURPOSE

Excess body weight is a risk factor for colorectal cancer (CRC) and may also adversely affect survival in CRC patients.

METHODS

This study examined the relation of body mass index (BMI), which was self-reported at cohort entry and after 5.7 ± 0.8 years, with CRC-specific and all-cause survival among 4,204 incident cases of invasive CRC in the multiethnic cohort. Cox regression analysis with age as time metric and BMI as time-varying exposure was applied to estimate hazard ratios (HR) and 95% confidence intervals (CIs) while adjusting for relevant covariates.

RESULTS

Over 6.0 ± 4.7 years of follow-up, 1,976 all-cause and 1,095 CRC-specific deaths were recorded. The mean time interval between cohort entry and diagnosis was 7.6 ± 4.7 years. No association with CRC-specific survival was detected in men (HR5units = 0.94; 95%CI 0.84-1.04) or women (HR5units = 0.98; 95%CI 0.89-1.08). In men, all-cause survival also showed no relation with BMI (HR5unit = 0.97; 95%CI 0.90-1.06), whereas it was reduced in women (HR5units = 1.10; 95%CI 1.03-1.18). Interactions of BMI with ethnicity were only significant for obesity. Obese Latino and overweight Native Hawaiian men as well as overweight African-American women experienced significantly better CRC-specific survival than whites. Overweight Japanese men and African-American women had better all-cause survival and obese Latino women had the lowest all-cause survival (HRobese = 1.74; 95%CI 1.08-2.80).

CONCLUSIONS

This analysis detected little evidence for an adverse effect of excess body weight on CRC-specific survival, but all-cause survival was reduced in women. These findings suggest that adiposity may be less important for CRC survival than as an etiologic factor.

Diet and lifestyle in survivors of colorectal cancer

Much research supports the association between diet and lifestyle in the development of colorectal cancer. Recent studies have demonstrated an association between various energy balance host factors (obesity, physical inactivity, and certain dietary factors) and outcomes. This review summarizes the impact of modifiable lifestyle factors, including prediagnosis and postdiagnosis adiposity, physical activity, and diet, on the prognosis of patients with colorectal cancer. The article focuses on associations of these factors in survivors of stage I to III colorectal cancer, and summarizes the possible mechanisms for the association between modifiable lifestyle factors and the prognosis of patients with colorectal cancer.

Association between body mass index and mortality for colorectal cancer survivors: overall and by tumor molecular phenotype

BACKGROUND

Microsatellite instability (MSI) and BRAF mutation status are associated with colorectal cancer survival, whereas the role of body mass index (BMI) is less clear. We evaluated the association between BMI and colorectal cancer survival, overall and by strata of MSI, BRAF mutation, sex, and other factors.

METHODS

This study included 5,615 men and women diagnosed with invasive colorectal cancer who were followed for mortality (maximum: 14.7 years; mean: 5.9 years). Prediagnosis BMI was derived from self-reported weight approximately one year before diagnosis and height. Tumor MSI and BRAF mutation status were available for 4,131 and 4,414 persons, respectively. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were estimated from delayed-entry Cox proportional hazards models.

RESULTS

In multivariable models, high prediagnosis BMI was associated with higher risk of all-cause mortality in both sexes (per 5-kg/m(2); HR, 1.10; 95% CI, 1.06-1.15), with similar associations stratified by sex (Pinteraction: 0.41), colon versus rectum (Pinteraction: 0.86), MSI status (Pinteraction: 0.84), and BRAF mutation status (Pinteraction: 0.28). In joint models, with MS-stable/MSI-low and normal BMI as the reference group, risk of death was higher for MS-stable/MSI-low and obese BMI (HR, 1.32; P value: 0.0002), not statistically significantly lower for MSI-high and normal BMI (HR, 0.86; P value: 0.29), and approximately the same for MSI-high and obese BMI (HR, 1.00; P value: 0.98).

CONCLUSIONS

High prediagnosis BMI was associated with increased mortality; this association was consistent across participant subgroups, including strata of tumor molecular phenotype.

IMPACT

High BMI may attenuate the survival benefit otherwise observed with MSI-high tumors.

Prediagnostic Physical Activity and Colorectal Cancer Survival: Overall and Stratified by Tumor Characteristics

BACKGROUND

Physical activity is associated with a lower incidence of colorectal cancer; however, the relationship of physical activity with colorectal cancer survival is not yet clear. We evaluated the association between prediagnostic physical activity and colorectal cancer survival, overall and accounting for tumor markers associated with colorectal cancer survival: BRAF and KRAS mutation status and microsatellite instability (MSI) status.

METHODS

Participants were 20- to 74-year-old colorectal cancer patients diagnosed between 1998 and 2007 from the population-based Seattle Colon Cancer Family Registry (S-CCFR). Self-reported physical activity in the years preceding colorectal cancer diagnosis was summarized as average metabolic equivalent task hours per week (MET-h/wk; n = 1,309). Somatic BRAF and KRAS mutations and MSI status were evaluated on a subset of patients (n = 1043). Cox regression was used to estimate HRs and 95% confidence intervals (CI) for overall and disease-specific survival after adjusting for relevant confounders. Stratified analyses were conducted across categories of BRAF, KRAS, and MSI, as well as tumor stage and site.

RESULTS

Higher prediagnostic recreational physical activity was associated with significantly more favorable overall survival (HR for highest vs. lowest category, 0.70; 95% CI, 0.52-0.96); associations were similar for colorectal cancer-specific survival. Results consistently indicated a favorable association with physical activity across strata defined by tumor characteristics.

CONCLUSION

Individuals who were physically active before colorectal cancer diagnosis experienced better survival than those who were inactive or minimally active.

IMPACT

Our results support existing physical activity recommendations for colorectal cancer patients and suggest that the beneficial effect of activity is not specific to a particular molecular phenotype of colorectal cancer.

Pre-diagnostic concordance with the WCRF/AICR guidelines and survival in European colorectal cancer patients: a cohort study

BACKGROUND

Cancer survivors are advised to follow lifestyle recommendations on diet, physical activity, and body fatness proposed by the World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) for cancer prevention. Previous studies have demonstrated that higher concordance with these recommendations measured using an index score (the WCRF/AICR score) was associated with lower cancer incidence and mortality. The aim of this study was to evaluate the association between pre-diagnostic concordance with WCRF/AICR recommendations and mortality in colorectal cancer (CRC) patients.

METHODS

The association between the WCRF/AICR score (score range 0-6 in men and 0-7 in women; higher scores indicate greater concordance) assessed on average 6.4 years before diagnosis and CRC-specific (n = 872) and overall mortality (n = 1,113) was prospectively examined among 3,292 participants diagnosed with CRC in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (mean follow-up time after diagnosis 4.2 years). Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality.

RESULTS

The HRs (95% CIs) for CRC-specific mortality among participants in the second (score range in men/women: 2.25-2.75/3.25-3.75), third (3-3.75/4-4.75), and fourth (4-6/5-7) categories of the score were 0.87 (0.72-1.06), 0.74 (0.61-0.90), and 0.70 (0.56-0.89), respectively (P for trend <0.0001), compared to participants with the lowest concordance with the recommendations (category 1 of the score: 0-2/0-3). Similar HRs for overall mortality were observed (P for trend 0.004). Meeting the recommendations on body fatness and plant food consumption were associated with improved survival among CRC cases in mutually adjusted models.

CONCLUSIONS

Greater concordance with the WCRF/AICR recommendations on diet, physical activity, and body fatness prior to CRC diagnosis is associated with improved survival among CRC patients.

Association between body mass index and prognosis of colorectal cancer: a meta-analysis of prospective cohort studies

Studies have reported conflicting results on the association between body mass index (BMI) and prognosis of colorectal cancer. Therefore, we have conducted a meta-analysis of prospective studies, which examined the association of pre- and post-diagnostic BMI with colorectal cancer-specific mortality and all-cause mortality in patients with colorectal cancer. We searched Medline and EMBASE database published between 1970 and September 2014. A total of 508 articles were identified, of which 16 prospective cohort studies were included for the current meta-analysis. The analysis included 58,917 patients who were followed up over a period ranging from 4.9 to 20 years (median: 9.9 years). We found that being underweight before cancer diagnosis was associated with increased all-cause mortality (Relative risk [RR]: 1.63, 95% CI: 1.18-2.23, p < 0.01) and being obese (BMI ≥ 30 kg/m(2)) before cancer diagnosis was associated with increased colorectal cancer-specific mortality (RR: 1.22, 95% CI: 1.003-1.35, p < 0.01) and all-cause mortality (RR: 1.25, 95% CI: 1.14-1.36, p < 0.01). On the other hand, being underweight (RR: 1.33, 95% CI: 1.20-1.47, p < 0.01), obese (RR: 1.08, 95% CI: 1.03-1.3, p < 0.01), and class II/III obese (BMI ≥ 35 kg/m(2); RR: 1.13, 95% CI: 1.04-1.23, p < 0.01) after diagnosis were associated with significantly increased all-cause mortality. Being obese prior to diagnosis of colorectal cancer was associated with increased colorectal cancer-specific mortality and all-cause mortality, whereas being obese after diagnosis was associated with increased all-cause mortality. The associations with being underweight may reflect reverse causation. Maintaining a healthy body weight should be discussed with colorectal cancer survivors.

Pre- and postdiagnosis physical activity, television viewing, and mortality among patients with colorectal cancer in the National Institutes of Health-AARP Diet and Health Study

PURPOSE

Physical inactivity has been associated with higher mortality risk among survivors of colorectal cancer (CRC), but the independent effects of pre- versus postdiagnosis activity are unclear, and the association between watching television (TV) and mortality in survivors of CRC is previously undefined.

METHODS

We analyzed the associations between prediagnosis (n = 3,797) and postdiagnosis (n = 1,759) leisure time physical activity (LTPA) and TV watching and overall and disease-specific mortality among patients with CRC. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% CIs, adjusting for known mortality risk factors.

RESULTS

Comparing survivors of CRC reporting more than 7 hours per week (h/wk) of prediagnosis LTPA with those reporting no LTPA, we found a 20% lower risk of all-cause mortality (HR, 0.80; 95% CI, 0.68 to 0.95; P for trend = .021). Postdiagnosis LTPA of ≥ 7 h/wk, compared with none, was associated with a 31% lower all-cause mortality risk (HR, 0.69; 95% CI, 0.49 to 0.98; P for trend = .006), independent of prediagnosis activity. Compared with 0 to 2 TV hours per day (h/d) before diagnosis, those reporting ≥ 5 h/d of TV before diagnosis had a 22% increased all-cause mortality risk (HR, 1.22; 95% CI, 1.06 to 1.41; P trend = .002), and more postdiagnosis TV watching was associated with a nonsignificant 25% increase in all-cause mortality risk (HR, 1.25; 95% CI, 0.93 to 1.67; P for trend = .126).

CONCLUSION

LTPA was inversely associated with all-cause mortality, whereas more TV watching was associated with increased mortality risk. For both LTPA and TV watching, postdiagnosis measures independently explained the association with mortality. Clinicians should promote both minimizing TV time and increasing physical activity for longevity among survivors of CRC, regardless of previous behaviors.

Association of change in physical activity and body weight with quality of life and mortality in colorectal cancer: a systematic review and meta-analysis

PURPOSE

A systematic review and a meta-analysis were performed to assess the associations between change over time in physical activity and weight and quality of life and mortality in colorectal cancer patients.

METHODS

The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched for English language articles published between January 1, 1990 and October 7, 2013. These articles reported results for changes in physical activity and body weight, assessed at pre- to post-diagnosis or at post-diagnosis only. A random effects model was used to analyze pooled quality of life and mortality estimates.

RESULTS

Seven eligible studies were identified and analyzed. Increased physical activity was associated with higher overall quality of life scores (N = 3 studies; standardized mean difference (SMD) = 0.74, 95 % confidence interval (CI) = 0.66-0.82), reduced disease-specific mortality risk (hazard ratio (HRpooled) = 0.70, 95 % CI = 0.55-0.85), and reduced overall mortality (HRpooled = 0.75, CI = 0.62-0.87) (N = 2 studies). Weight gain was not associated with disease-specific (HRpooled = 1.02, CI = 0.84-1.20) or overall (HRpooled = 1.03, CI = 0.86-1.19) mortality (N = 3 studies).

CONCLUSIONS

Increased physical activity was associated with improved quality of life, a reduced risk of colorectal cancer, and overall mortality rate. Given the paucity of the literature published on this topic, this finding should be interpreted with caution.

Pre-diagnostic anthropometry and survival after colorectal cancer diagnosis in Western European populations

General and abdominal adiposity are associated with a high risk of developing colorectal cancer (CRC), but the role of these exposures on cancer survival has been less studied. The association between pre-diagnostic anthropometric characteristics and CRC-specific and all-cause death was examined among 3,924 men and women diagnosed with CRC between 1992 and 2009 in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Over a mean follow-up period of 49 months, 1,309 deaths occurred of which 1,043 (79.7%) were due to CRC. In multivariable analysis, pre-diagnostic BMI ≥ 30 kg/m(2) was associated with a high risk for CRC-specific (HR = 1.26, 95% CI = 1.04-1.52) and all-cause (HR = 1.32, 95% CI = 1.12-1.56) death relative to BMI <25 kg/m(2). Every 5 kg/m(2) increase in BMI was associated with a high risk for CRC-specific (HR = 1.10, 95% CI = 1.02-1.19) and all-cause death (HR = 1.12, 95% CI = 1.05-1.20); and every 10 cm increase in waist circumference was associated with a high risk for CRC-specific (HR = 1.09, 95% CI = 1.02-1.16) and all-cause death (HR = 1.11, 95% CI = 1.05-1.18). Similar associations were observed for waist-to-hip and waist-to-height ratios. Height was not associated with CRC-specific or all-cause death. Associations tended to be stronger among men than in women. Possible interactions by age at diagnosis, cancer stage, tumour location, and hormone replacement therapy use among postmenopausal women were noted. Pre-diagnostic general and abdominal adiposity are associated with lower survival after CRC diagnosis.

Body mass index and risk of second obesity-associated cancers after colorectal cancer: a pooled analysis of prospective cohort studies

PURPOSE

To determine whether prediagnostic body mass index (BMI) is associated with risk of second obesity-associated cancers in colorectal cancer (CRC) survivors, and whether CRC survivors have increased susceptibility to obesity-associated cancer compared with cancer-free individuals.

PATIENTS AND METHODS

Incident first primary CRC cases (N = 11,598) were identified from five prospective cohort studies. We used Cox proportional hazards regression models to examine associations between baseline (prediagnostic) BMI and risk of second obesity-associated cancers (postmenopausal breast, kidney, pancreas, esophageal adenocarcinoma, endometrium) in CRC survivors, and compared associations to those for first obesity-associated cancers in the full cohort.

RESULTS

Compared with survivors with normal prediagnostic BMI (18.5-24.9 kg/m(2)), those who were overweight (25-29.9 kg/m(2)) or obese (30+ kg/m(2)) had greater risk of a second obesity-associated cancer (n = 224; overweight hazard ratio [HR], 1.39; 95% CI, 1.01 to 1.92; obese HR, 1.47; 95% CI, 1.02 to 2.12; per 5-unit change in BMI HR, 1.12; 95% CI, 0.98 to 1.29). The magnitude of risk for developing a first primary obesity-associated cancer was similar (overweight HR, 1.18; 95% CI, 1.14 to 1.21; obese HR, 1.61; 95% CI, 1.56 to 1.66; per 5-unit change in BMI HR, 1.23; 95% CI, 1.21 to 1.24). Before diagnosis CRC patients were somewhat more likely than the overall cohort to be overweight (44% v 41%) or obese (25% v 21%).

CONCLUSION

CRC survivors who were overweight or obese before diagnosis had increased risk of second obesity-associated cancers compared with survivors with normal weight. The risks were similar in magnitude to those observed for first cancers in this population, suggesting increased prevalence of overweight or obesity, rather than increased susceptibility, may contribute to elevated second cancer risks in colorectal cancer survivors compared with the general population. These results support emphasis of existing weight guidelines for this high-risk group.

Development of a risk-screening tool for cancer survivors to participate in unsupervised moderate- to vigorous-intensity exercise: results from a survey study

BACKGROUND

The health benefits of exercise increase in dose-response fashion among cancer survivors. However, it is unclear how to identify cancer survivors who may require a pre-exercise evaluation before they progress from the common recommendation of walking to unsupervised moderate- to vigorous-intensity exercise.

OBJECTIVE

To clarify how to identify cancer survivors who should undergo a pre-exercise evaluation before they progress from the common recommendation of walking to unsupervised moderate- to vigorous-intensity exercise.

DESIGN

Electronic survey.

PARTICIPANTS

Forty-seven (n = 47) experts in the field of exercise physiology, rehabilitation medicine, and cancer survivorship.

SETTING

Not applicable.

METHODS

We synthesized peer-reviewed guidelines for exercise and cancer survivorship and identified 82 health factors that may warrant a pre-exercise evaluation before a survivor engages in unsupervised moderate- to vigorous-intensity exercise. The 82 health factors were classified into 3 domains: (1) clinical health factors; (2) comorbidity and device health factors; and (3) medications. We surveyed a sample of experts asking them to identify which of the 82 health factors among cancer survivors would indicate the need for a pre-exercise evaluation before they engaged in moderate- to vigorous-intensity exercise.

MAIN OUTCOME MEASUREMENTS

The response rate to our survey was 75% (n = 47). Across the 3 domains of health factors, acute symptoms, comorbidities, and medications related to cardiovascular disease were agreed on to indicate a pre-exercise evaluation for survivors before they engaged in unsupervised moderate- to vigorous-intensity exercise. Other health factors in the survey included hematologic, musculoskeletal, systemic, gastrointestinal, pulmonary, and neurological symptoms and comorbidities. Eighteen experts (38%) said it was difficult to provide absolute answers because no 2 patients are alike, and their decisions are made on a case-by-case basis.

CONCLUSIONS

The results from this expert survey will help to identify which cancer survivors should undergo a pre-exercise evaluation before they engage in unsupervised moderate- to vigorous-intensity exercise.

The risk of colonic adenomas and colonic cancer in obesity

Increasing body fatness has been associated with an increased burden from colorectal cancer. An increased susceptibility spanning the entire continuum from precancerous adenomatous polyps to the development of colorectal cancer, poor outcome with treatment, and reduced survival when compared to those with normal body weight has been described. It is unknown which age period and which degree and duration of excess weight are associated with increased colorectal cancer risk. It is uncertain whether weight loss can reverse this risk. If it can, how long will the new lower or normal weight be maintained to effect enduring risk reduction? Furthermore, it is controversial whether the increased burden of colorectal cancer warrants earlier and/or more frequent screening for obese persons. This article reviews the relationship between obesity and colorectal neoplasia, explores the postulated mechanism of carcinogenesis, discusses interventions to reduce the burden of disease, and suggests future directions of research.

Association of obesity and overweight with overall survival in colorectal cancer patients: a meta-analysis of 29 studies

PURPOSE

Previous studies that assessed the relationship between obesity, overweight, and survival in colorectal cancer (CRC) have provided conflicting results. Therefore, we quantitatively summarized existing evidence to estimate the association between obesity/overweight and overall survival (OS) in CRC patients and explored potentially important sources of variability.

METHODS

Eligible studies were identified via PubMed and EMBASE searches. The summary hazard ratio (sHR) was estimated using a fixed-effects or random-effects model according to the heterogeneity between the studies. Meta-regression and subgroup analyses were performed to explore potential sources of heterogeneity.

RESULTS

A total of 29 eligible studies, with 51,303 CRC patients, were finally included. The overall analysis showed worse OS among obese patients [sHR 1.10, 95 % confidence intervals (CI) 1.06-1.15], but not among overweight patients (sHR 0.92, 95 % CI 0.86-1.00), than in normal-weight patients. Considerable heterogeneity was observed across studies, which was primarily attributed to the timing of body mass index (BMI) assessment (meta-regression p < 0.05). The association between obesity and worse OS was strengthened when BMI was assessed before diagnosis (sHR 1.30, 95 % CI, 1.17-1.44). Conversely, post-diagnostic, in particular post-treatment, overweight was associated with a better OS (sHR 0.79, 95 % CI 0.70-0.91). Other factors, including gender, geographic location, and stage, may also modify the prognostic value of obesity or overweight.

CONCLUSIONS

Obese but not overweight patients appear to have worse OS than normal-weight patients with CRC. The associations of obesity and overweight with OS in CRC patients majorly depend upon the timing of BMI assessment.

Postdiagnosis body mass index and risk of mortality in colorectal cancer survivors: a prospective study and meta-analysis

PURPOSE

Aim of this study was to investigate the association between postdiagnosis body mass index (BMI) and all-cause mortality in colorectal cancer (CRC) survivors in a prospective study and meta-analysis.

METHODS

We conducted a prospective cohort study on 2,143 CRC survivors in Germany. Participants were recruited to the study on average 4 years after diagnosis, and postdiagnosis BMI was assessed at recruitment using a self-administered questionnaire. CRC survivors were followed up for a mean time of 3.5 years. The association between BMI and all-cause mortality was investigated using multivariable Cox proportional hazards models. Additionally, we performed a meta-analysis of studies on postdiagnosis BMI and all-cause mortality (n = 5, including this study) by applying random-effects models.

RESULTS

In the prospective analysis, 349 participants died. BMI was not statistically significantly associated with all-cause mortality. Compared to normal weight survivors, the hazard ratios (HRs) [95% confidence interval (CI)] for all-cause mortality in underweight, overweight and obese survivors were 1.65 (0.79-3.45), 0.80 (0.62-1.03) and 0.84 (0.62-1.14), respectively. In the meta-analysis, individuals with underweight were at increased risk for all-cause mortality [HR (95% CI) 1.72 (1.18-2.49)], whereas individuals with overweight had a lower risk [HR (95% CI) 0.79 (0.71-0.88)], compared to normal weight subjects. For obesity, the risk of mortality was also reduced with only borderline significance [HR (95% CI) 0.88 (0.77-1.00)].

CONCLUSIONS

While the present study as well as single previously published studies showed that overweight was associated with a non-significant reduced risk for all-cause mortality, our meta-analysis indicated a decreased mortality risk among overweight CRC survivors.

Association between physical activity and mortality among breast cancer and colorectal cancer survivors: a systematic review and meta-analysis

BACKGROUND

Physical activity improves physical function during and after cancer treatment, but whether physical activity imparts survival benefit remains uncertain.

DESIGN

Using prospective studies published through June 2013, we conducted a systematic review and random-effects meta-analysis of pre- and post-diagnosis physical activity in relation to total and cancer mortality among breast or colorectal cancer survivors.

RESULTS

Sixteen studies of breast cancer survivors and seven studies of colorectal cancer survivors yielded 49095 total cancer survivors, including 8129 total mortality cases and 4826 cancer mortality cases. Comparing the highest versus lowest levels of pre-diagnosis physical activity among breast cancer survivors, the summary relative risks (RRs) of total and breast cancer mortality were 0.77 [95% confidence interval (CI) = 0.69-0.88] and 0.77 (95% CI = 0.66-0.90, respectively. For post-diagnosis physical activity, the summary RRs of total and breast cancer mortality were 0.52 (95% CI = 0.42-0.64) and 0.72 (95% CI = 0.60-0.85), respectively. For pre-diagnosis physical activity among colorectal cancer survivors, the summary RRs of total and colorectal cancer mortality were 0.74 (95% CI = 0.63-0.86) and 0.75 (95% CI = 0.62-0.91), respectively. For post-diagnosis physical activity, the summary RRs of total and colorectal cancer mortality were 0.58 (95% CI = 0.48-0.70) and 0.61 (95% CI = 0.40-0.92), respectively. Each 10 metabolic equivalent task-hour/week increase in post-diagnosis physical activity (equivalent to current recommendations of 150 min/week of at least moderate intensity activity) was associated with 24% (95% CI = 11-36%) decreased total mortality risk among breast cancer survivors and 28% (95% CI = 20-35%) decreased total mortality risk among colorectal cancer survivors. Breast or colorectal cancer survivors who increased their physical activity by any level from pre- to post-diagnosis showed decreased total mortality risk (RR = 0.61; 95% CI = 0.46-0.80) compared with those who did not change their physical activity level or were inactive/insufficiently active before diagnosis.

CONCLUSION

Physical activity performed before or after cancer diagnosis is related to reduced mortality risk among breast and colorectal cancer survivors.

Excess adiposity and survival in patients with colorectal cancer: a systematic review

Excess adiposity is an established risk factor for incident colorectal cancer (CRC) but whether this association extrapolates to poorer survival is unclear. We undertook a systematic review to examine relationships between measures of adiposity and survival in patients with CRC. For distinction, we included pre-diagnosis exposure and CRC-related mortality. We performed dose-response meta-analyses and assessed study quality using eight domains of bias. Six study categories were identified based on (i) timing of adiposity measurement relative to survival analysis time zero and (ii) clinical setting. Several types of adiposity measurements were reported; body mass index (BMI) was the commonest. For pre-diagnosis cohorts, baseline BMI negatively impacted on CRC-related mortality in men only (risk estimate per 5 kg m(-2)  = 1.19, 95% confidence intervals: 1.14-1.25). The other groups were pre-diagnosis BMI but diagnosis as time zero; population-based cohorts; treatment cohorts; observational analyses within adjuvant chemotherapy trials; patients with metastatic CRC - each had several biases (e.g. treatment selection, reverse causality) and sources of confounding (e.g. chemotherapy 'capping'). Overall, there was insufficient evidence for a strong link between adiposity and survival. These findings demonstrate an important principle: an established link between an exposure (here, adiposity) and increased cancer incidence does not necessarily extrapolate into an inferior post-treatment outcome.

Impact of physical activity on cancer-specific and overall survival of patients with colorectal cancer

Background. Physical activity (PA) reduces incidence of colorectal cancer (CRC). Its influence on cancer-specific (CSS) and overall survival (OS) is controversial. Methods. We performed a literature-based meta-analysis (MA) of observational studies, using keywords “colorectal cancer, physical activity, and survival” in PubMed and EMBASE. No dedicated MA was found in the Cochrane Library. References were cross-checked. Pre- and postdiagnosis PA levels were assessed by MET. Usually, “high” PA was higher than 17 MET hour/week. Hazard ratios (HRs) for OS and CSS were calculated, with their 95% confidence interval. We used more conservative adjusted HRs, since variables of adjustment were similar between studies. When higher PA was associated with improved survival, HRs for detrimental events were set to <1. We used EasyMA software and fixed effect model whenever possible. Results. Seven studies (8056 participants) were included, representing 3762 men and 4256 women, 5210 colon and 1745 rectum cancers. Mean age was 67 years. HR CSS for postdiagnosis PA (higher PA versus lower) was 0.61 (0.44–0.86). The corresponding HR OS was 0.62 (0.54–0.71). HR CSS for prediagnosis PA was 0.75 (0.62–0.91). The corresponding HR OS was 0.74 (0.62–0.89). Conclusion. Higher PA predicted a better CSS. Sustained PA should be advised for CRC. OS also improved (reduced cardiovascular risk).

Association between physical activity and mortality in colorectal cancer: a meta-analysis of prospective cohort studies

Several prospective cohort studies have examined the association between prediagnosis and/or postdiagnosis physical activity (PA) on colorectal cancer outcomes and reported conflicting results. To quantitatively assess this association, we have conducted a meta-analysis of prospective studies. Databases and reference lists of relevant studies were searched using MEDLINE and EMBASE up to January 2013. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using random-effects models. For this meta-analysis, a total of seven prospective cohort studies were included. The analysis included 5,299 patients for prediagnosis PA and 6,348 patients for postdiagnosis PA, followed up over a period ranging from 3.8 to 11.9 years. The analyses showed that patients who participated in any amount of PA before diagnosis had a RR of 0.75 (95% CI: 0.65-0.87, p < 0.001) for colorectal cancer-specific mortality compared to patients who did not participate in any PA. Those who participated in high PA before diagnosis (vs. low PA) had a RR of 0.70 (95% CI: 0.56-0.87, p = 0.002). Similarly, patients who participated in any PA after diagnosis had a RR of 0.74 (95% CI: 0.58-0.95, p = 0.02) for colorectal cancer-specific mortality compared to patients who did not participate in any PA. Those who participated in high PA after diagnosis (vs. low PA) had a RR of 0.65 (95% CI: 0.47-0.92, p = 0.01). Similar inverse associations of prediagnosis or postdiagnosis PA were found for all-cause mortality. In conclusion, both prediagnosis and postdiagnosis PA were associated with reduced colorectal cancer-specific mortality and all-cause mortality.

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.

A cohort study of metformin exposure and survival in patients with stage I-III colorectal cancer

BACKGROUND

Preclinical evidence suggests a beneficial effect of metformin in colorectal cancer. This study aimed to investigate associations between metformin exposure and colorectal cancer-specific survival using population-level data.

METHODS

Adult patients with stage I-III colorectal cancer diagnosed from 2001 to 2006 were identified from the National Cancer Registry Ireland. Use of metformin and other antidiabetic medications was determined from a linked national prescription claims database. Multivariate Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for associations between prediagnostic metformin exposure (versus nonmetformin antidiabetic drugs) and colorectal cancer-specific mortality. Models were stratified by antidiabetic drug coprescription and intensity of metformin exposure.

RESULTS

The cohort included 207 diabetics who received metformin, 108 diabetics not exposed to metformin, and 3,501 nondiabetic patients. In multivariate analyses, a nonsignificant reduction in colorectal cancer-specific mortality was observed for metformin-exposed patients relative to other treated diabetics (HR, 0.61; 95% CI, 0.37-1.01). In stratified analyses, no significant association was observed for patients receiving low-intensity metformin or metformin in combination with other antidiabetic drugs. High-intensity exclusive metformin use was associated with a significant reduction in colorectal cancer-specific mortality (HR, 0.44; 95% CI, 0.20-0.95).

CONCLUSIONS

Significant associations between metformin exposure and colorectal cancer-specific mortality were observed only for high-intensity exclusive metformin use in the diabetic cohort.

IMPACT

This study provides moderate evidence of an association between metformin exposure and improved colorectal cancer survival in a diabetic population. Additional studies in larger cohorts, with detailed information on diabetes severity, are required to confirm these results.

Physical activity, tumor PTGS2 expression, and survival in patients with colorectal cancer

BACKGROUND

Higher levels of physical activity are associated with lower colorectal carcinoma incidence and mortality, perhaps through influencing energy balance, cellular prosta7 systemic inflammation. Although evidence suggests interactive effects of energetics, sedentary lifestyle, and tumor CTNNB1 (β-catenin) or CDKN1B (p27) status on colon cancer prognosis, interactive effects of physical activity and tumor PTGS2 (the official symbol for COX-2) status on clinical outcome remain unknown.

METHODS

Using molecular pathological epidemiology database of 605 stage I-III colon and rectal cancers in two prospective cohort studies (the Nurse's Health Study and the Health Professionals Follow-up Study), we examined patient survival according to postdiagnosis physical activity and tumor PTGS2 status (with 382 PTGS2-positive and 223 PTGS2-negative tumors by immunohistochemistry). Cox proportional hazards models were used to calculate colorectal cancer-specific mortality HR, adjusting for clinical and other tumor variables including microsatellite instability status.

RESULTS

Among PTGS2-positive cases, compared with the least active first quartile, the multivariate HRs (95% confidence interval) were 0.30 (0.14-0.62) for the second, 0.38 (0.20-0.71) for the third, and 0.18 (0.08-0.41) for the fourth quartile of physical activity level (Ptrend = 0.0002). In contrast, among PTGS2-negative cases, physical activity level was not significantly associated with survival (Ptrend = 0.84; Pinteraction = 0.024, between physical activity and tumor PTGS2 status).

CONCLUSIONS

Postdiagnosis physical activity is associated with better survival among patients with PTGS2-positive tumors but not among patients with PTGS2-negative tumors.

IMPACT

Immunohistochemical PTGS2 expression in colorectal carcinoma may serve as a predictive biomarker in pathology practice, which may predict stronger benefit from exercise.