Case-control Study In Ontario Research Articles

Exposure to ambient polycyclic aromatic hydrocarbons and early-onset female breast cancer in a case-control study in Ontario, Canada.

Ambient polycyclic aromatic hydrocarbons (PAHs) are a class of toxicologically important and understudied air pollutants. Epidemiologic evidence suggests that chronic exposure to PAHs increases breast cancer risk; however, there are few studies in nonoccupational settings that focus on early-onset diagnoses. The relationship between residentially-based ambient PAH concentrations and female breast cancer, among those 18-45 years of age, was characterized in the Ontario Environment and Health Study (OEHS). The OEHS was a population-based case-control study undertaken in Ontario, Canada between 2013 and 2015. Primary incident breast cancers were identified within 3 months of diagnosis, and a population-based series of controls were recruited. Concentrations of ambient PAHs, using fluoranthene as a surrogate, were derived using a chemical transport model at a 2.5 km spatial resolution. These estimates were assigned to participants' residences at the time of the interview and 5 years prior. Logistic regression was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) based on a quartile categorization of fluoranthene exposure while adjusting for a series of individual- and area-level risk factors. The shape of the exposure-response trend was evaluated using cubic splines. Median fluoranthene exposure for cases and controls was 0.0017 µg/m3 and 0.0014 µg/m3, respectively. In models adjusted for a parsimonious set of risk factors, the highest quartile of exposure was associated with an increased risk of breast cancer (OR = 2.16; 95% CI = 1.22, 3.84). Restricted spline analyses revealed nonlinear dose-response patterns. These findings support the hypothesis that ambient PAH exposures increases the risk of early-onset breast cancer.

Associations of neighborhood greenspace, and active living environments with autism spectrum disorders: A matched case-control study in Ontario, Canada

BackgroundIncreasing evidence links early life residential exposure to natural urban environmental attributes and positive health outcomes in children. However, few studies have focused on their protective effects on the risk of autism spectrum disorder (ASD). The aim of this study was to investigate the associations of neighborhood greenspace, and active living environments during pregnancy with ASD in young children (≤6 years). MethodsWe conducted a population-based matched case-control study of singleton term births in Ontario, Canada for 2012–2016. The ASD and environmental data was generated using the Ontario Autism Spectrum Profile, the Better Outcomes Registry & Network Ontario, and Canadian Urban Environmental Health Research Consortium. We employed conditional logistic regressions to estimate the odds ratio (OR) between ASD and environmental factors characterizing selected greenspace metrics and neighborhoods conducive to active living (i.e., green view index (GVI), normalized difference vegetation index (NDVI), tree canopy, park proximity and active living environments index (ALE)). ResultsWe linked 8643 mother-child pairs, including 1554 cases (18%). NDVI (OR 1.034, 0.944–1.024, per Inter Quartile Range [IQR] = 0.08), GVI (OR 1.025, 95% CI 0.953–1.087, per IQR = 9.45%), tree canopy (OR 0.992, 95% CI 0.903–1.089, per IQR = 6.24%) and the different categories of ALE were not associated with ASD in adjusted models for air pollution. In contrast, living closer to a park was protective (OR 0.888, 0.833–0.948, per 0.06 increase in park proximity index), when adjusted for air pollution. ConclusionsThis study reported mixed findings showing both null and beneficial effects of green spaces and active living environments on ASD. Further investigations are warranted to elucidate the role of exposure to greenspaces and active living environments on the development of ASD.

Chronic Psychotic Disorders and Correctional Involvement: A Population-Based Matched Case-Control Study in Ontario, Canada.

Individuals with chronic psychotic disorders are overrepresented in correctional facilities, but little is known about factors that increase the risk of correctional involvement. The objective of this study was to compare individuals with chronic psychotic disorders who were released from correctional facilities in Ontario to individuals with chronic psychotic disorders but no correctional involvement on sociodemographic, clinical, and prior mental health-related health service utilization characteristics. All individuals with chronic psychotic disorders who were released from a provincial correctional facility in Ontario in 2010 were matched (1:2) by age and sex to Ontario residents with chronic psychotic disorders and no correctional involvement. Covariates included sociodemographic (rural residence, marginalization such as residential instability quintile, material deprivation quintile, dependency quintile, and ethnic concentration quintile) and clinical (duration of chronic psychotic disorder and comorbidities) characteristics, and mental health-related health service utilization characteristics (primary care physician, psychiatrist and emergency department visits, and hospitalizations) 1 and 3 years prior to correctional involvement. The association between correctional involvement and prior health service utilization was measured by estimating incidence rate ratios using Poisson and negative-binomial regressions. Individuals with correctional involvement (N = 3,197) lived in neighbourhoods with higher material deprivation and residential instability, and had a shorter duration of illness, and more psychosocial comorbidities (e.g., behavioural issues and depression) than individuals without correctional involvement (N = 6,393). Adjusting for sociodemographic and clinical variables, individuals with correctional involvement had a higher rate of mental health-related primary care physician visits, emergency department visits, and hospitalizations but a lower rate of psychiatrist visits prior to correctional involvement, compared to individuals without correctional involvement. Despite higher mental health-related comorbidities and higher rates of accessing acute mental health services among individuals with chronic psychotic disorders and correctional involvement, visits to psychiatrists prior to involvement were low.

Maternal and childhood medical history and the risk of childhood brain tumours: a case-control study in Ontario, Canada.

Studies to date have yielded inconclusive results as to whether maternal medical history during pregnancy, and a child's early-life medical history contribute to the development of childhood brain tumours (CBTs). This study examined associations between maternal and childhood medical history and the risk of CBTs. The Childhood Brain Tumour Epidemiology Study of Ontario (CBREO) examined children 0-15 years of age with newly diagnosed CBTs from 1997 to 2003. Multivariable logistic regression analysis determined associations for prenatal medications and childhood medical history, adjusted for child's demographics, and maternal education. Analyses were stratified by histology. A latency period analysis was conducted using 12- and 24-month lead times. Maternal intake of immunosuppressants during the prenatal period was significantly associated with glial tumours (OR 2.73, 95% CI 1.17-6.39). Childhood intake of anti-epileptics was significantly associated with CBTs overall, after accounting for 12-month (OR 8.51, 95% CI 3.35-21.63) and 24-month (OR 6.04, 95% CI 2.06-17.70) lead time before diagnosis. No associations for other medications were found. This study underscores the need to examine potential carcinogenic effects of the medication classes highlighted and of the indication of medication use. Despite possible reverse causality, increased CBT surveillance for children with epilepsy might be warranted.

Abstract 10558: Association Between Concurrent Use of Diltiazem and DOACs and Risk of Bleeding in Atrial Fibrillation Patients

Introduction: Diltiazem is a commonly used pharmacotherapy in patients with atrial fibrillation (AF) with potential for a drug-drug interaction (DDI) with direct oral anticoagulants (DOACs). We aimed to assess the risk of bleeding after co-prescription of diltiazem and DOACs among adults with AF. Methods: We conducted a population-based, nested case-control study in Ontario, Canada. The study population included all patients with AF > 66 years on a DOAC between April 1, 2011-March 31, 2018. Cases were patients admitted with major bleeding (index date). Controls were matched in a 2:1 ratio to cases. We categorized exposure to diltiazem before the index date as: a) current users (diltiazem within 7 days); b) past users (diltiazem within 8 to 90 days); and c) unexposed (no diltiazem prescription or diltiazem prescription >90 days before index date). Conditional logistic regression models were used to examine the association between bleeding and diltiazem co-prescription. Results: Among 86,679 AF patients on a DOAC, we identified 2,766 cases (3.2%) admitted with major bleeding. The median age of AF patients was 80 years (interquartile range 75-85); 48.3% were women. After multivariable adjustment, there was a significant association between major bleeding and current use of diltiazem (adjusted odds ratio (aOR) 1.37; 95% confidence interval (CI) 1.08-1.73, p<0.009) but no significant association between major bleeding and past use of diltiazem (aOR 1.19, 95% CI 0.99-1.42, p=0.06) as compared with the unexposed group (Figure). Conclusions: Among older patients with AF on a DOAC, there was 37% increased odds of current use of diltiazem in those with versus without major bleeding.

Abstract 9368: Association Between Concurrent Use of Amiodarone and DOACs and Bleeding Risk in Atrial Fibrillation Patients

Introduction: Amiodarone is a commonly used pharmacotherapy in patients with atrial fibrillation (AF) with potential for drug-drug interactions (DDIs) with direct oral anticoagulants (DOACs). We aimed to assess the bleeding risk after co-prescription of amiodarone and DOACs among adults with AF. Methods: We conducted a population-based, nested case-control study in Ontario, Canada. The study population included all patients with AF > 66 years on a DOAC between April 1, 2011-March 31, 2018. Cases were patients admitted with major bleeding (index date). Controls were matched in a 2:1 ratio to cases. We categorized exposure to amiodarone before the index date as: a) current users (amiodarone within 60 days); b) past users (amiodarone within 61 to 140 days); and c) unexposed (no amiodarone prescription or amiodarone prescription >140 days before index date). Conditional logistic regression models were used to examine the association between bleeding and amiodarone co-prescription. Results: Among 86,679 AF patients on a DOAC, we identified 2,766 cases (3.2%) admitted with major bleeding. The median age of AF patients was 80 years (interquartile range 75-85); 48.3% were women. After multivariable adjustment, there was a significant association between major bleeding and current use of amiodarone (adjusted odds ratio (aOR) 1.53; 95% confidence interval (CI) 1.24-1.89, p<0.001) but no significant association between major bleeding and past use of amiodarone (aOR 1.13, 95% CI 0.76-1.68, p=0.545) as compared with the unexposed group. Conclusions: Among older patients with AF on a DOAC, there was 53% increased odds of current use of amiodarone in those with versus without major bleeding.

Association Between Concurrent Use of Amiodarone and DOACs and Risk of Bleeding in Patients With Atrial Fibrillation

Amiodarone is a commonly used pharmacotherapy in patients with atrial fibrillation (AF), with a potential for drug-drug interactions with direct oral anticoagulants (DOACs). We aimed to assess the bleeding risk after co-prescription of amiodarone and DOACs among adults with AF. We conducted a population-based, nested case-control study in Ontario, Canada. The study population included all patients with AF aged >66 years on a DOAC between April 1, 2011 and March 31, 2018. Cases were patients admitted with major bleeding (index date). Controls were matched in a 2:1 ratio to cases. We categorized exposure to amiodarone before the index date as: (1) current users (amiodarone within 60 days), (2) past users (amiodarone within 61 to 140 days), and (3) unexposed (no amiodarone prescription or amiodarone prescription >140 days before index date). Conditional logistic regression models were used to examine the association between bleeding and amiodarone co-prescription. Among 86,679 patients with AF on a DOAC, we identified 2,766 cases (3.2%) admitted with major bleeding. The median age of patients with AF was 80 years (interquartile range 75 to 85); 48.3% were women. After multivariable adjustment, there was a significant association between major bleeding and current use of amiodarone (adjusted odds ratio 1.53; 95% confidence interval 1.24 to 1.89, p <0.001) but no significant association between major bleeding and past use of amiodarone (adjusted odds ratio 1.13, 95% confidence interval 0.76 to 1.68, p=0.545) compared with the unexposed group. In conclusion, among older patients with AF on a DOAC, there was 53% increased odds of major bleeding with the current use of amiodarone.

Association between concurrent use of diltiazem and DOACs and risk of bleeding in atrial fibrillation patients.

Diltiazem is a commonly used medication in patients with atrial fibrillation (AF) with potential for a drug-drug interaction (DDI) with direct oral anticoagulants (DOACs). We aimed to assess the risk of major bleeding after co-prescription of diltiazem and DOACs among adults with AF. We conducted a population-based, nested case-control study in Ontario, Canada. The study population included all patients with AF > 66years on a DOAC between April 1, 2011, and March 31, 2018. Cases were patients admitted with major bleeding (index date). Each case was matched to two controls. We categorized exposure to diltiazem before the index date as: (a) current users (diltiazem use within 7days); (b) recent users (diltiazem use within 8 to 90days); and (c) unexposed (no diltiazem prescription or diltiazem prescription > 90days before index date). Conditional logistic regression models were used to examine the association between bleeding and diltiazem co-prescription. Among 86,679 AF patients on a DOAC, the median age of AF patients was 80years (interquartile range 75-85); 48.3% were women. We identified 2,766 cases (3.2%) who were hospitalized with major bleeding. After multivariable adjustment, there was a significant association between major bleeding and current use of diltiazem (adjusted odds ratio (aOR) 1.37; 95% confidence interval (CI) 1.08-1.73, p < 0.009) but no significant association between major bleeding and recent use of diltiazem (aOR 1.19, 95% CI 0.99-1.42, p = 0.06) as compared with the unexposed group. Current use of diltiazem was associated with major bleeding among AF patients receiving a DOAC.

Oxycodone, Hydromorphone, and the Risk of Suicide: A Retrospective Population-Based Case-Control Study.

Opioids have been increasingly associated with suicide, but whether they are independent contributors is unclear. Oxycodone and hydromorphone are commonly prescribed high-potency opioids that can differentially affect mood. The objective of this study was to explore whether oxycodone and hydromorphone are differentially associated with suicide. We conducted a retrospective population-based case-control study in Ontario, Canada, from 1992 to 2014. Using coronial data, we defined case subjects as individuals who died by suicide involving an opioid overdose. Each of these was matched with up to four controls who died of accidental opioid overdose. We ascertained exposure to oxycodone, hydromorphone, and other opioids from postmortem toxicology testing. We used odds ratios and 95% confidence intervals to examine whether opioid-related suicide was disproportionately associated with oxycodone relative to hydromorphone. We identified 438 suicides and 1212 accidental deaths, each of which involved either oxycodone or hydromorphone but not both. The median age at death was 49years and 51% were men. After adjusting for a history of self-harm, psychiatric illness, and exposure to other opioids, we found that oxycodone was more strongly associated with suicide than hydromorphone (adjusted odds ratio 1.59; 95% confidence interval 1.20-2.11). In a secondary analysis, we observed a trend of similar magnitude in which combined exposure to oxycodone and hydromorphone was more strongly associated with suicide than hydromorphone alone (adjusted odds ratio 1.68; 95% confidence interval 0.92-3.09). While preliminary, these findings support the possibility that some high-potency opioids might independently influence the risk of suicide in susceptible individuals.

Trajectories of physical activity, from young adulthood to older adulthood, and pancreatic cancer risk; a population-based case-control study in Ontario, Canada

BackgroundThere is inconsistent evidence on the association between physical activity and pancreatic cancer risk and few studies have investigated early life or life-course physical activity. The objective of this study was to evaluate the association between trajectories of physical activity across the life-course and pancreatic cancer risk.MethodsA population-based case-control study was conducted (2011–2013) using cases (n = 315) from the Ontario Pancreas Cancer Study and controls (n = 1254) from the Ontario Cancer Risk Factor Study. Self-reported recall of moderate and vigorous physical activity was measured at three time points: young adulthood (20s–30s), mid-adulthood (40s–50s) and older-adulthood (1 year prior to questionnaire completion). Physical activity trajectories were identified using latent class analysis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from multivariable logistic regression adjusted for covariates: age, sex, race, alcohol, smoking, vegetable, fruit and meat consumption, and family history of pancreatic cancer.ResultsSix life-course physical activity trajectories were identified: inactive at all ages (41.2%), low activity at all ages (31.9%), increasingly active (3.6%), high activity in young adulthood with substantial decrease (13.0%), high activity in young adulthood with slight decrease (5.0%), and persistent high activity (5.3%). Compared to the inactive at all ages trajectory, the associations between each trajectory and pancreatic cancer after confounder adjustment were: low activity at all ages (OR: 1.11; 95% CI: 0.75, 1.66), increasingly active (OR: 1.11; 95% CI: 0.56, 2.21), high activity in young adulthood with substantial decrease in older adulthood (OR: 0.76; 95% CI: 0.47, 1.23), high activity in young adulthood with slight decrease in older adulthood (OR: 0.98; 95% CI: 0.62, 1.53), and persistently high activity (OR: 1.50; 95% CI: 0.86, 2.62). When time periods were evaluated separately, the OR for the association between high moderate activity in the 20s–30s and pancreatic cancer was 0.89 (95% CI: 0.64, 1.25) and some sex differences were observed.ConclusionDistinct life-course physical activity trajectories were identified, but there was no evidence that any of the trajectories were associated with pancreatic cancer. Future studies with larger sample sizes are needed to understand the associations between physical activity trajectories over the life-course and pancreatic cancer risk.

Abstract 623: Iron intake, oxidative stress-related genes, and breast cancer risk

Abstract Background: Iron has been shown to enhance breast carcinogenesis in animal models through generation of oxidative stress, although epidemiological evidence of the association between iron intake and breast cancer risk remains inconclusive. This study investigated associations between different types of iron intake and breast cancer risk, and whether these associations were modified by genetic polymorphisms in antioxidant enzymes, including manganese superoxide dismutase (MnSOD) and glutathione S-transferases M1 (GSTM1) and T1 (GSTT1). Methods: A population-based case-control study in Ontario, Canada recruited 3,030 breast cancer cases identified from the Ontario Cancer Registry and 3,402 controls from random digit dialing. Iron intake from foods and supplements was assessed using a 178-item food frequency questionnaire. Multivariable logistic regression analyses were used to evaluate associations between breast cancer risk and intakes of dietary, supplemental, and total (dietary plus supplemental) iron, among all women and stratified by menopausal status. Associations were also examined by hormone receptor [estrogen receptor (ER)/progesterone receptor (PR)] tumor subtype. Among women providing saliva (DNA) samples (1,696 cases and 1,761 controls), interactions between iron intake and genetic polymorphisms were assessed using the likelihood ratio test. Results: Among all women, intakes of dietary, supplemental, and total iron were not associated with breast cancer risk, overall or by tumor subtype. Among premenopausal women, there was an increase in breast cancer risk for the ER–PR– subtype associated with higher intakes (highest vs. lowest quintile) of dietary [odds ratio (OR) = 1.4; 95% confidence interval (CI): 0.9–2.4] and total (OR = 1.8; 95% CI: 1.1–2.9) iron (P for trend &amp;lt; 0.05). Among postmenopausal women, supplemental iron intake (&amp;gt;18 vs. 0 mg/day) was associated with reduced breast cancer risk (OR = 0.7; 95% CI: 0.5–0.9), with similar associations across tumor subtypes. Associations of dietary and total iron intake with overall breast cancer risk were modified by GSTT1 and/or GSTM1/T1 combined genotypes (P for interaction &amp;lt; 0.05). For example, among women with deletions in both GSTM1 and GSTT1 loci, higher dietary iron intake was associated with increased breast cancer risk (OR = 2.1; 95% CI: 1.1–4.2), whereas null or inverse associations were found among women with other GSTM1/T1 genotypes. Conclusions: Results from this study suggest that higher dietary and total iron intake may be associated with increased risk of ER–PR– breast cancer among premenopausal women, whereas higher supplemental iron intake may be associated with reduced postmenopausal breast cancer risk. In addition, associations between iron intake and breast cancer risk may be modified by polymorphisms in oxidative stress-related genes. Our ongoing work will investigate heme and non-heme iron intake in relation to breast cancer risk. Citation Format: Vicky C. Chang, Michelle Cotterchio, Susan J. Bondy, Joanne Kotsopoulos. Iron intake, oxidative stress-related genes, and breast cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 623.

Overdose Risk in Young Children of Women Prescribed Opioids

Over the past 20 years, the prescribing of opioids has increased dramatically in North America, with parallel increases in opioid addiction, overdose, and associated deaths. We examined whether young children of women prescribed opioids were at increased risk of opioid overdose. We conducted a population-based, nested case control study in Ontario, Canada, between 2002 and 2015. We identified children aged ≤10 years, whose mothers received publicly funded prescriptions for an opioid or a nonsteroidal antiinflammatory drug (comparator analgesic) in the preceding year. Cases were children who presented to hospital for or died of opioid overdose. Each case was matched with 4 controls with no opioid overdose. The primary outcome was the risk of opioid overdose. We identified 103 children who presented to the hospital with opioid overdose and matched them with 412 controls. Half of the children with opioid overdose were <2 years old. Compared with controls, children with an opioid overdose were far more likely to have a mother who received a prescription opioid (unadjusted odds ratio, 2.41; 95% confidence interval, 1.68-3.45) and who was prescribed antidepressants. The most commonly implicated overdose opioids were codeine (53.4%), oxycodone (32.0%), and methadone (15.5%). Young children of mothers prescribed opioids are at a markedly increased risk of overdose. Physicians, pharmacists, and parents should take measures to mitigate the risk of opioid-related harm to children, such as prescribing smaller quantities, emphasizing the importance of secure medication storage, and the prompt disposal of unused opioids.

The Association of Dyslipidemia With Chronic Lymphocytic Leukemia: A Population-Based Study.

Metabolic syndrome (MetS) is a risk factor for development of cancer. Because aberrant lipid metabolism is a pathogenic feature of chronic lymphocytic leukemia (CLL), our objective was to determine if CLL patients have a higher prevalence of MetS preceding diagnosis and to determine the impact of lipid-lowering medications on survival. We conducted a population-based case-control study in Ontario, Canada, using administrative databases of adults age 66 years and older to compare the prevalence of MetS preceding CLL with age- and sex-matched control subjects. Logistic regression was used to study the association between MetS and its components to CLL. The Kaplan-Meier method and Cox Regression were used to investigate survival. All statistical tests were two-sided. We identified 2124 persons with CLL and 7935 control subjects from January 1, 2000, to December 31, 2005, with follow-up until March 31, 2014, three years from the date of last contact with the health care system, or death. The mean age was 75.6 years, 20.2% had diabetes, 35.8% had hypertension, and 17.6% had dyslipidemia. In multivariable analysis, dyslipidemia (odds ratio [OR] = 1.26, 95% confidence interval [CI] = 1.11 to 1.44, P < .001) and hypertension (OR = 1.12, 95% CI = 1.01 to 1.25, P = .03) were associated with the development of CLL, whereas MetS and diabetes were not. Lipid-lowering medication was associated with a statistically significant improved survival in patients with CLL (HR = 0.53, 95% CI = 0.47 to 0.61, P < .001). We demonstrate a higher prevalence of dyslipidemia preceding a diagnosis of CLL compared with control subjects, supporting preclinical data. Lipid-lowering medications appear to confer a survival advantage in CLL. Prospective studies are needed to confirm these results and test their potential as therapeutic applications.

Varenicline and Risk of Self-Harm: A Nested Case-Control Study.

BackgroundSmoking remains a serious public health concern. Pharmacotherapy for smoking cessation, including bupropion and varenicline, are proven means to increase quit rates. Post-marketing reports describing suicidal behaviours have raised concerns about the safety of varenicline. However, whether varenicline imparts a higher risk of suicide relative to bupropion remains uncertain.MethodsA population-based nested case-control study in Ontario, Canada, from April 1, 2011 to March 31, 2015 was conducted. Subjects were residents of Ontario aged 18 years and older with publicly funded drug coverage receiving either bupropion or varenicline for smoking cessation. We defined cases were those with a hospitalization or emergency department visit for suicide or non-fatal self-harm within 90 days of treatment. For each case, we identified up to fifty controls from the same cohort matched on age, sex, history of self-harm, use of selected psychotropic medications, alcohol abuse and prior admission to a mental health unit. Adjusted odds ratio were used to compare the risk of suicide/self-harm of varenicline to bupropion.ResultsWe identified 331 cases and 5,346 matched-controls. Following adjustment for potential confounders, we found that varenicline was not associated with an increased risk of suicide/self-harm relative to bupropion (adjusted odds ratio 1.15; 95% confidence interval 0.71 to 1.87).InterpretationTreatment with varenicline does not appear to significantly increase the risk of suicide or self-harm relative to bupropion.

Trimethoprim-Sulfamethoxazole and Spironolactone — A Potentially Deadly Combination?

Researchers in Canada previously demonstrated that patients who are taking both trimethoprim-sulfamethoxazole (TMP/SMX) and spironolactone are at excess risk for being hospitalized with hyperkalemia (NEJM JW Gen Med Nov 1 2011 and BMJ 2011; 343 : d5228). Now, the same team has performed a population-based case-control study in Ontario to determine whether this interaction might confer risk for sudden death, …

Risk factors for sporadic domestically acquired Salmonella serovar Enteritidis infections: a case-control study in Ontario, Canada, 2011

In Ontario, Canada, the number of Salmonella Enteritidis (SE) cases increased over the years 2005-2010. A population-based case-control study was undertaken from January to August 2011 for the purpose of identifying risk factors for acquiring illness due to SE within Ontario. A total of 199 cases and 241 controls were enrolled. After adjustment for confounders, consuming any poultry meat [adjusted odds ratio (aOR) 2·24, 95% confidence interval (CI) 1·31-3·83], processed chicken (aOR 3·32, 95% CI 1·26-8·76) and not washing hands following handling of raw eggs (OR 2·82, 95% CI 1·48-5·37) were significantly associated with SE infection. The population attributable fraction was 46% for any poultry meat consumption and 10% for processed chicken. Poultry meat continues to be identified as a risk factor for SE illness. Control of SE at source, as well as proper food handling practices, are required to reduce the number of SE cases.

Genetic Variants in Vitamin D Pathway Genes and Risk of Pancreas Cancer; Results from a Population-Based Case-Control Study in Ontario, Canada

Recent studies of 25-hydroxyvitamin D (25(OH)D) levels and pancreas cancer have suggested a potential role of the vitamin D pathway in the etiology of this fatal disease. Variants in vitamin-D related genes are known to affect 25(OH)D levels and function and it is unknown if these variants may influence pancreatic cancer risk. The association between 87 single nucleotide polymorphisms (SNPs) in 11 genes was evaluated within the Ontario Pancreas Cancer Study, a population-based case-control study. Pancreatic cancer cases with pathology confirmed adenocarcinoma were identified from the Ontario Cancer Registry (n = 628) and controls were identified through random digit dialing (n = 1193). Age and sex adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. SNPs in the CYP24A1, CYP2R1, calcium sensing receptor (CASR), vitamin D binding protein (GC), retinoid X receptor-alpha (RXRA) and megalin (LRP2) genes were significantly associated with pancreas cancer risk. For example, pancreas cancer risk was inversely associated with CYP2R1 rs10741657 (AA versus GG, OR = 0.70; 95%CI: 0.51–0.95) and positively with CYP24A1 rs6127119 (TT versus CC. OR = 1.94; 95%CI: 1.28–2.94). None of the associations were statistically significant after adjustment for multiple comparisons. Vitamin D pathway gene variants may be associated with pancreas cancer risk and future studies are needed to understand the possible role of vitamin D in tumorigenesis and may have implications for cancer-prevention strategies.

The social determinants of health and pandemic H1N1 2009 influenza severity.

We explored the effects of social determinants of health on pandemic H1N1 2009 influenza severity and the role of clinical risk factors in mediating such associations. We used multivariate logistic regression with generalized estimating equations to examine the associations between individual- and ecological-level social determinants of health and hospitalization for pandemic H1N1 2009 illness in a case-control study in Ontario, Canada. During the first pandemic phase (April 23-July 20, 2009), hospitalization was associated with having a high school education or less and living in a neighborhood with high material or total deprivation. We also observed the association with education in the second phase (August 1-November 6, 2009). Clinical risk factors for severe pandemic H1N1 2009 illness mediated approximately 39% of the observed association. The main clinical risk factors for severe pandemic H1N1 2009 illness explain only a portion of the associations observed between social determinants of health and hospitalization, suggesting that the means by which the social determinants of health affect pandemic H1N1 2009 outcomes extend beyond clinically recognized risk factors.

Prevalence and Incidence of Colorectal Cancer Comorbidities

S (ACE) AEP Vol. 20, No. 9 September 2010: 691–724 700 CONCLUSION: The interaction with family history of cancer supports the biological plausibility of our findings, as similar results have been found for breast cancer and radiation. This observational data will increase awareness about potential risks associated with CT scans and the need to minimize the use of unnecessary exams. P26 TOTAL ENERGY, MACRONUTRIENTS AND COLORECTAL CANCER: A CASE-CONTROL STUDY IN ONTARIO AND NEWFOUNDLAND AND LABRADOR Z Sun, J Zhao, P P Wang, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada PURPOSE: The associations of total energy and macronutrients with colorectal cancer risk remain controversial. The objective of this study is to examine such associations through a population based case-control study in Ontario (ON) and Newfoundland and Labrador (NL). METHODS:Data for this case-control study were fromOntario and Newfoundland Familial Colorectal Cancer Registries. Cases were pathologically confirmed new colorectal cancer patients aged 20–74 years during 1999–2003 (NL), 1997–2000 (ON Phase I) and 2003–2006 (ON Phase II). Controls were a sex and age-group matched random sample of the population in each province. Intakes of total energy and macronutrients were derived from a food frequency questionnaire. Multivariate logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence interval (95%CI) after adjusting for total energy and other potential confounding factors. Tests for trend were used to assess dose-response relationships. RESULTS: High intake of total energy was significantly related to an increased risk of CRC (ORZ1.56, 95% CI: 1.21–2.01), whereas inverse associations emerged for intakes of protein (ORZ0.85, 95%CI: 0.69–1.00), carbohydrate (ORZ0.81, 95%CI: 0.63–1.00) and total dietary fibre (ORZ0.84, 95% CI:0.67–0.99). CONCLUSIONS: Findings of this study provides further evidence that diets high in energy may increase the risk, whereas diets high in protein, fibre, and carbohydrate may reduce the risk ofCRC.These results underline the importance of some aspects of total energy and macronutrients and consequently the potential for prevention through dietary changes. P27 PREVALENCE AND INCIDENCE OF COLORECTAL CANCER COMORBIDITIES W Langeberg, M Danese, K Lindquist, M Gleeson, R Griffiths, C O’Malley, Amgen, Outcomes Insights, Thousand Oaks, CA BACKGROUND: The comorbidity profile for colorectal cancer (CRC) patients can change markedly after diagnosis. To assess this, we evaluated the comorbidity burden of CRC cases and matched controls in the year before and after diagnosis. METHODS: Cases included persons 66 years from the SEERMedicare (S-M) database diagnosed 1998 to 2002 with incident, primary CRC (nZ50,168). Persons without cancer (nZ49,929) were randomly selected from the S-M file, matched to cases on gender and county of residence, and assigned a pseudo-diagnosis date from their matched case. The prevalences of 34 comorbid conditions were calculated for the year before diagnosis date. The 3and 12-month incidence rates were calculated per 1,000 person-years among patients initially free of the condition. Rates in the controls were standardized to the age and race distribution of the cases. RESULTS: The prevalence of comorbidities in the year before diagnosis was similar among cases and controls, with little variance due to age, sex, or race. However, the 3and 12-month incidence of comorbidities was notably higher in the cases than the controls. The highest 12-month incidence rates were for: anemia [cases: 476.8 (95% CI: 468.7, 484.8), controls: 31.9 (95% CI: 30.2, 33.7)]; electrolyte disorder [cases: 393.9 (95% CI: 386.9, 401.0), controls: 51.0 (95% CI: 48.7, 53.3)]; infectious disease [cases: 328.9 (95% CI: 322.5, 335.4), controls: 60.3 (95% CI: 57.7, 62.9)]; and hypertension [cases: 189.2 (95% CI: 182.5), controls: 48.0 (95% CI: 45.2, 50.8)]. Incidence rates tended to increase with age and stage. CONCLUSION: Our data suggest marked increases in rates of several comorbidities after CRC diagnosis. This could be a result of the cancer or treatment, or these conditions might be under-diagnosed. The diagnosis of new comorbidities can be anticipated in the treatment of colorectal cancer patients, most likely as a function of the diagnostic process surrounding detection and treatment. P28 ANTIDEPRESSANT USE AMONG BREAST CANCER SURVIVORS AND MORTALITY R Haque, C Avila, J Shi, J Chung, C Cheetham, VP Quinn, Kaiser Permanente Southern California, Research & Evaluation, Pasadena, CA PURPOSE: Despite tamoxifen’s success in reducing the risk of breast cancer (BCa) recurrence, its notable side effects include hot flashes and night sweats. Antidepressants have been used to relieve some of these symptoms. However, few laboratory studies suggest that certain common antidepressants may interfere with tamoxifen’s effectiveness. Our goal was to determine whether concomitant tamoxifen and antidepressant use is associated with all cause mortality. METHODS: We assembled a large cohort of women who were diagnosed with their first BCa in 1996–2006 and treated with tamoxifen and followed through 12/31/07 using

Total Energy, Macronutrients and Colorectal Cancer: A Case-Control Study in Ontario and Newfoundland and Labrador

Total Energy, Macronutrients and Colorectal Cancer: A Case-Control Study in Ontario and Newfoundland and Labrador