Rachel Murphy

Background/Objectives: Demographic, health history, and lifestyle factors have been associated with prognosis of colorectal cancer (CRC), but the mechanisms underlying these associations remain poorly understood. Our primary objective was to explore the association of these factors with expression of two biomarkers in CRC, SPARC and PD-L1, for which lower and higher levels of expression, respectively, have been associated with poorer CRC prognosis. Methods: Participants were drawn from the British Columbia Generations Project (BCGP), who at time of recruitment, provided data on various demographic, health history, and lifestyle factors. Formalin-fixed paraffin-embedded blocks were obtained for 49 incident BCGP CRC cases and used to create tissue microarrays. Slides created from the microarrays were stained with SPARC and PD-L1 antibodies and analyzed to calculate H-scores as measures of expression in both epithelial and non-epithelial tissues. Linear regression analyses were used to evaluate associations between the various factors and ln-transformed H-scores.Results: In CRC tumour epithelium, smoking was associated with a 0.53-fold lower level of SPARC expression (p=0.05); a similar though non-significant, association was observed in non-epithelial tumour tissue. Higher income was associated with a 1.33-fold greater level of SPARC expression in tumor non-epithelial tissue (p=0.04); a similar effect was not observed in tumour epithelium. Higher stage was associated with a 0.74-fold lower level of non-epithelial tumour SPARC expression (p=0.04). A similar non-significant effect was observed in tumour epithelium. PD-L1 expression in tumour epithelium was 2.84-fold greater among females (p=0.005). A similar non-significant effect was observed in tumour non-epithelial tissue. History of CRC screening was statistically significantly associated with 2-fold greater levels of PD-L1 expression in tumour epithelial and non-epithelial tissues (p=0.04). Conclusion: Associations of SPARC expression with smoking, income, and stage, but not PD-L1 expression with biological sex and history of CRC screening, were consistent with the previously established associations of these factors with CRC prognosis. Larger scale studies with prognostic data are needed, but our results suggest that differences in expression of SPARC may contribute to the previously observed impacts of factors on CRC prognosis. However, additional work to understand the role of PD-L1 in CRC prognosis is needed.

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Background: Mental health disorders are highly prevalent in the Canadian population and has been associated with cancer risk; however, previous findings in literature are inconsistent (1–4). This study aims to elucidate the relationship between mental health disorders and cancer risk, as well as explore the potential mediating effects of lifestyle behaviours.Methods: A cohort study was conducted with 34,571 participants aged 40-69 years from the province of Quebec. Depression was conceptualized from the PHQ-9, antidepressant use, and either a positive screen from PHQ-9 scores, antidepressant use, or self-report of physician diagnosis. Anxiety was defined using the GAD-7, and co-morbid depression and anxiety was assessed using the PHQ-9 and the GAD-7. Cox proportional hazards regression models were used to investigate the association between mental health exposures and risk of prostate, lung, and all cancers combined. Mediating effects of health behaviours were assessed using Baron and Kenny mediation criteria., then a Quasi-Bayesian/Monte Carlo approximation was used to obtain confidence intervals. Results: For risk of all cancers combined, there was a modest positive association with all mental health exposures, however none reached significance with full adjustment. No relationships reached significance for prostate cancer. There were positive associations between mental health disorders and lung cancer risk, but only anxiety and lung cancer in women was significant with full adjustment (HR = 1.67, 95% CI: 1.01-2.76). Women had consistently higher risk estimates than men for all cancer and lung cancer risk for the majority of exposures. Smoking status mediated the relationship between depression (PHQ-9) and lung cancer, anxiety and lung cancer, and co-morbidity and lung cancer by 27%, 18%, and 26%, respectively in women. In men, smoking status mediated 17% of the relationship between depression (PHQ-9, antidepressant use, or self-report of physician diagnosis) on all cancers. Conclusions: Positive associations were observed between mental health disorders and overall and lung cancer risk, however few relationships reached significance. Risk estimates were generally higher in women than in men, suggesting a differential risk. Smoking status mediated a significant proportion of the relationships between mental health disorders and cancer risk.

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Background: The Food Explorers (FE) program was designed and developed for use with kindergarten and grade 1 children. Offered within the classroom setting, the program aims to encourage children to identify and experience a wide variety of foods. The objective of this study was to examine the impact of the program on children’s willingness to try new and familiar foods. Methods: A quasi- experimental pre-post design was employed to evaluate the impact of the program on children’s familiarity and willingness to try novel and familiar test foods. Children in the FE group participated in food -related classroom activities led by teachers, over 5 months and the control group were taught the standard curriculum. Assessments of familiarity and willingness to try foods was completed at baseline and after 5 months in both groups. Parent-perceived food neophobia was also assessed using a validated scale at both times. Open-ended questions were used to assess parent and teacher experience with the program. Results: Analyses were conducted with 194 children (FE group, n=102 and control group, n=92). Knowledge of familiar foods increased over time in both groups and a significant group by time interaction was observed with 2 test foods (out of 10) at follow-up, indicating increased knowledge in the FE group, compared to the control group. Willingness to try the test foods, measured as food preference scores significantly increased for five novel foods in the FE group compared to the control group. No significant difference was observed in parent-perceived food neophobia scores between groups. Parents indicated positive experiences with respect to their children’s willingness to try new foods at home. Positive experiences were also noted by the teachers.Conclusion: While there is some evidence to suggest that the FE program may positively impact food knowledge and willingness to try new foods in kindergarten and grade 1 children, limitations of the study and implementation of the FE program warrant consideration when considering the impact of the program. The findings of the study provide valuable information on barriers for implementation of the FE program in classrooms and will inform future evaluations of the program.

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Background: Cancer survivors may be motivated to change their diet for weight management and improved survival. However, dietary behaviours and obesity are influenced by a range of individual-level and environmental factors rather than simply individual choices. This study aims to understand the diet quality of cancer survivors and its association with obesity and neighbourhood environment in comparison to non-cancer controls.Methods: A cross-sectional study was conducted with 19,973 participants aged 35 to 69 years from Atlantic Canada. A healthy eating index (HEI) was used to evaluate diet quality using dietary intake collected from a food frequency questionnaire. Obesity was assessed using anthropometric and bio-impedance measures. Neighbourhood environment data were derived from the Canadian dissemination-area-level census data. Multivariable multi-level models were used to investigate HEI and its association with obesity in cancer survivors compared to non-cancer controls. The associations between neighbourhood deprivation, population density and HEI were also explored. Results: Cancer survivors (n = 1930) had a higher mean HEI than non-cancer controls (mean difference: 0.45, 95% CI [0.07, 0.84]). Body mass index, waist circumference, waist-to-hip ratio, body fat percentage, and fat-free mass index were not associated with HEI, while trunk fat percentage had a weak positive association with HEI (0.45, 95% CI [0.08, 0.83]). The diet-obesity relationship did not significantly differ by cancer status. Mean HEI was lower in the most compared to the least socially deprived neighbourhoods (-0.56, 95% CI [-0.88, -0.25]), and in the most compared to the least dense neighbourhoods (-0.39, 95% CI [-0.77, -0.01]), but was not associated with material deprivation. Associations between diet quality, material deprivation and population density significantly differed by urbanicity. In rural areas, diet quality decreased with increasing material deprivation and decreasing population density, while the reverse was true for urban areas. Conclusion: Cancer survivors had a slightly better diet quality than non-cancer controls, but both groups are in need of dietary improvement. Diet was not associated with obesity measures in the cancer and non-cancer groups but was associated with neighbourhood deprivation and population density with evidence of urban-rural differences, suggesting the complexity of dietary behaviour and the need for multi-level interventions.

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