Background: Recent updates to physical activity guidelines highlight the importance of reducing sedentary time. However, at present, only general recommendations are possible (ie, “Sit less, move more”). There remains a need to investigate the strength, temporality, specificity, and dose–response nature of sedentary behavior associations with chronic disease, along with potential underlying mechanisms. Methods: Stemming from a recent research workshop organized by the Sedentary Behavior Council themed “Sedentary behaviour mechanisms—biological and behavioural pathways linking sitting to adverse health outcomes,” this paper (1) discusses existing challenges and scientific discussions within this advancing area of science, (2) highlights and discusses emerging areas of interest, and (3) points to potential future directions. Results: A brief knowledge update is provided, reflecting upon current and evolving thinking/discussions, and the rapid accumulation of new evidence linking sedentary behavior to chronic disease. Research “action points” are made at the end of each section—spanning from measurement systems and analytic methods, genetic epidemiology, causal mediation, and experimental studies to biological and behavioral determinants and mechanisms. Conclusion: A better understanding of whether and how sedentary behavior is causally related to chronic disease will allow for more meaningful conclusions in the future and assist in refining clinical and public health policies/recommendations.

Sedentary behavior (sitting/lying at low energy expenditure while awake) is emerging as an important risk factor that may compromise the health-related quality of life (HRQoL) of colorectal cancer (CRC) survivors. We examined associations of sedentary time with HRQoL in CRC survivors, 2-10 years post-diagnosis. In a cross-sectional study, stage I-III CRC survivors (n = 145) diagnosed (2002-2010) at Maastricht University Medical Center+, the Netherlands, wore the thigh-mounted MOX activity monitor 24 h/day for seven consecutive days. HRQoL outcomes were assessed by validated questionnaires (EORTC QLQ-C30, WHODAS II, Checklist Individual Strength, and Hospital Anxiety and Depression Scale). Confounder-adjusted linear regression models were used to estimate associations with HRQoL outcomes of MOX-derived total and prolonged sedentary time (in prolonged sedentary bouts ≥ 30 min), and usual sedentary bout duration, corrected for waking wear time. On average, participants spent 10.2 h/day sedentary (SD, 1.6), and 4.5 h/day in prolonged sedentary time (2.3). Mean usual sedentary bout duration was 27.3 min (SD, 16.8). Greater total and prolonged sedentary time, and longer usual sedentary bout duration were associated with significantly (P < 0.05) lower physical functioning, and higher disability and fatigue scores. Greater prolonged sedentary time and longer usual sedentary bout duration also showed significant associations with lower global quality of life and role functioning. Associations with distress and social functioning were non-significant. Sedentary time was cross-sectionally associated with poorer HRQoL outcomes in CRC survivors. Prospective studies are needed to investigate whether sedentary time reduction is a potential target for lifestyle interventions aiming to improve the HRQoL of CRC survivors.

Background: Well-designed studies on lifestyle and health-related quality of life (HRQoL) in colorectal cancer survivors based on a biopsychosocial instead of a traditional biomedical approach are warranted. We report on the applicability of the International Classification of Functioning, Disability, and Health (ICF) as useful biopsychosocial framework to improve research on how lifestyle influences colorectal cancer survivors' HRQoL, using the Energy for life after ColoRectal cancer (EnCoRe) study as an example. Methods: The ICF was used to develop a conceptual model for studying lifestyle and colorectal cancer survivors' HRQoL, by identifying relevant factors from literature and mapping them within the ICF. Subsequently, this model was used for selection of measurement instruments and biomarkers. By linking meaningful concepts within selected measures to the ICF, we could assess the ICF coverage of our developed conceptual model. Results: Within selected measures, 450 meaningful concepts were identified, of which 88% were linked to the ICF. The linking process resulted in 132 distinctive ICF categories assigned (38% within “Body Functions,” 2% within “Body Structures,” 46% within “Activities and Participation,” and 14% within “Environmental Factors”). Conclusions: The selected EnCoRe study measures broadly cover ICF domains relevant to colorectal cancer survivors, stressing the relevance of using a biopsychosocial approach for studying this population's HRQoL. Impact: The developed conceptual model will guide data analyses and interpretation, and facilitate early transfer of results for development, evaluation, and implementation of personalized multidisciplinary lifestyle interventions. We recommend the ICF as an invaluable framework for improving the quality and scope of HRQoL studies. Cancer Epidemiol Biomarkers Prev; 23(7); 1394–405. ©2014 AACR.

The population of colorectal cancer (CRC) survivors is growing and many survivors experience deteriorated health-related quality of life (HRQoL) in both early and late post-treatment phases. Identification of CRC survivors at risk for HRQoL deterioration can be improved by using prediction models. However, such models are currently not available for oncology practice. As a starting point for developing prediction models of HRQoL for CRC survivors, a comprehensive overview of potential candidate HRQoL predictors is necessary. Therefore, a systematic literature review was conducted to identify candidate predictors of HRQoL of CRC survivors. Original research articles on associations of biopsychosocial factors with HRQoL of CRC survivors were searched in PubMed, Embase, and Google Scholar. Two independent reviewers assessed eligibility and selected articles for inclusion (N = 53). Strength of evidence for candidate HRQoL predictors was graded according to predefined methodological criteria. The World Health Organization’s International Classification of Functioning, Disability and Health (ICF) was used to develop a biopsychosocial framework in which identified candidate HRQoL predictors were mapped across the main domains of the ICF: health condition, body structures and functions, activities, participation, and personal and environmental factors. The developed biopsychosocial ICF framework serves as a basis for selecting candidate HRQoL predictors, thereby providing conceptual guidance for developing comprehensive, evidence-based prediction models of HRQoL for CRC survivors. Such models are useful in clinical oncology practice to aid in identifying individual CRC survivors at risk for HRQoL deterioration and could also provide potential targets for a biopsychosocial intervention aimed at safeguarding the HRQoL of at-risk individuals.

The lifestyle recommendations of the World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) are primarily intended for cancer prevention. In the absence of specific recommendations for cancer survivors, we investigated adherence of colorectal cancer (CRC) survivors to the WCRF/AICR lifestyle recommendations and associations with health-related quality of life (HRQoL). The cross-sectional part of the Energy for life after ColoRectal cancer (EnCoRe) study was conducted in 155 CRC survivors (stage I-III), 2–10 years post diagnosis. Dietary intake, physical activity and general body fatness were measured by 7-d food diaries, by questionnaires and accelerometers and BMI, respectively. Adherence to each of the ten WCRF/AICR recommendations was scored as 0 (no/low adherence), 0·5 (moderate adherence) or 1 point (complete adherence), and summed into an overall adherence score (range: 0–10). HRQoL, disability and distress were assessed by validated questionnaires. Associations of the overall WCRF/AICR adherence score with HRQoL outcomes were analysed by confounder-adjusted linear regression. The mean adherence score was 5·1 (sd1·4, range: 1·5–8·5). In confounder-adjusted models, a higher adherence score was significantly associated with the HRQoL dimension better physical functioning (βper 1 point difference in score: 2·6; 95 % CI 0·2, 5·1) and with less fatigue (β: −3·3; 95 % CI −6·4, −0·1). In conclusion, higher adherence of CRC survivors to WCRF/AICR lifestyle recommendations for cancer prevention was associated with better physical functioning and with less fatigue. This study adds to the limited knowledge on adherence to lifestyle behaviours in CRC survivors and relationships with quality of life. Prospective studies are needed to investigate longitudinal associations.

Cial approach to investigate independent associations between self-reported LPA, MVPA, and multiple health-related quality of life (HRQoL) outcomes in 2- to 10-yr postdiagnosis colorectal cancer survivors. Methods Stage I–III colorectal cancer survivors diagnosed between 2002 and 2010 at Maastricht University Medical Center+, the Netherlands, were included in a cross-sectional study (n = 151). Time spent in LPA and MVPA (h·wk−1), and HRQoL outcome scores (0–100 points) were assessed by validated questionnaires. Results Median time spent in LPA and MVPA was 10.0 (interquartile range, 2.0–22.0) and 8.7 h·wk−1 (4.5–15.0), respectively. In multivariable linear regression models, both LPA and MVPA were significantly and independently associated with higher physical functioning (mean difference [MD] between highest and lowest quartile, 10.2; 95% confidence interval [CI], 0.2–20.3; and 14.5; 5.1–23.9, respectively; both P-trend < 0.05). In addition, LPA was significantly associated with higher role functioning (MD, 19.5; 95% CI, 6.9–32.1; P-trend < 0.01) and lower disability (MD, −9.9; 95% CI, −17.8 to −1.9; P-trend = 0.02), independent from MVPA. Subgroup analyses showed that beneficial associations between LPA and HRQoL were mainly observed in women and participants with multiple comorbidities. Conclusions Self-reported LPA, besides MVPA, was beneficially associated with multiple HRQoL outcomes in colorectal cancer survivors, especially in women and survivors with multiple comorbidities. Prospective studies are warranted to establish whether LPA is a suitable target for personalized lifestyle interventions to improve the HRQoL of colorectal cancer survivors....