Intrapersonal and social environment correlates of leisure-time physical activity for cancer prevention: a cross-sectional study among Canadian adults.

BACKGROUND: Little is known about the intrapersonal and social factors associated with sufficient physical activity (PA) for cancer prevention, which is greater than for cardiovascular health. METHODS: 1087 and 1684 randomly selected men and women, age 35-64, completed self-administered questionnaires on PA behavior and psycho-social characteristics. Using gender-stratified logistic regression, we investigated correlates of compliance with Canadian Society for Exercise Physiology PA guidelines for general health (150 min/wk), and the American Cancer Society (ACS; 225 min/wk) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AIRC; 420 min/wk) guidelines for cancer prevention. RESULTS: Only 39% and 19% of men and women met ACS and WCRF/AICR guidelines, respectively. Self-efficacy, scheduling PA and friend social support were positively correlated with recommended PA for cancer prevention. In men, poor self-rated health and perceived negative outcomes were negatively correlated and hypertension was positively correlated with meeting cancer prevention guidelines. For women, not being married and having a companion for PA were positively correlated with meeting cancer prevention guidelines. CONCLUSIONS: Few adults participate in sufficient PA for cancer risk reduction. Multidimensional public health strategies that incorporate intrapersonal and social factors and are tailored for each gender are needed to promote PA for cancer prevention.

The Sedentary Time and Activity Reporting Questionnaire (STAR-Q): reliability and validity against doubly labeled water and 7-day activity diaries.

We determined measurement properties of the Sedentary Time and Activity Reporting Questionnaire (STAR-Q), which was designed to estimate past-month activity energy expenditure (AEE). STAR-Q validity and reliability were assessed in 102 adults in Alberta, Canada (2009-2011), who completed 14-day doubly labeled water (DLW) protocols, 7-day activity diaries on day 15, and the STAR-Q on day 14 and again at 3 and 6 months. Three-month reliability was substantial for total energy expenditure (TEE) and AEE (intraclass correlation coefficients of 0.84 and 0.73, respectively), while 6-month reliability was moderate. STAR-Q-derived TEE and AEE were moderately correlated with DLW estimates (Spearman's ρs of 0.53 and 0.40, respectively; P < 0.001), and on average, the STAR-Q overestimated TEE and AEE (median differences were 367 kcal/day and 293 kcal/day, respectively). Body mass index-, age-, sex-, and season-adjusted concordance correlation coefficients (CCCs) were 0.24 (95% confidence interval (CI): 0.07, 0.36) and 0.21 (95% CI: 0.11, 0.32) for STAR-Q-derived versus DLW-derived TEE and AEE, respectively. Agreement between the diaries and STAR-Q (metabolic equivalent-hours/day) was strongest for occupational sedentary time (adjusted CCC = 0.76, 95% CI: 0.64, 0.85) and overall strenuous activity (adjusted CCC = 0.64, 95% CI: 0.49, 0.76). The STAR-Q demonstrated substantial validity for estimating occupational sedentary time and strenuous activity and fair validity for ranking individuals by AEE.

Quality indicators for ductal carcinoma in situ (DCIS) of the breast: development using a multidisciplinary delphi process and its use in monitoring population-based treatment.

BACKGROUND AND OBJECTIVES: Evaluation of the management of DCIS poses challenges, as standard breast cancer outcome measures such as mortality do not apply. We have developed quality indicators (QIs) to measure the quality of DCIS treatment in Alberta, Canada. METHODS: A modified Delphi process was used to determine QIs in the treatment of DCIS after review of evidence-based clinical practice guidelines. Patients diagnosed with DCIS from 2000 to 2001 (cohort 1) and 2009-2010 (cohort 2) were identified from the Alberta Cancer Registry and QIs were retrospectively abstracted. RESULTS: The expert panel developed eight QIs to assess the overall quality of care for DCIS patients. Five hundred eighty eligible patients were identified in the two cohorts. There was significant improvement in radiation oncology referral, radiation post lumpectomy and complete pathology reporting. Axillary staging significantly increased from 20% (axillary dissection in cohort 1) to 60% (sentinel node biopsy in cohort 2). Other QIs did not differ significantly. CONCLUSIONS: By developing QIs, performance measures for DCIS may assessed and compared over time. Although there have been significant improvements with pathology reporting and radiation oncology assessment and treatment, axillary staging rates are unexpectedly high, necessitating further investigation.

Incidence trends in head and neck cancers and human papillomavirus (HPV)-associated oropharyngeal cancer in Canada, 1992-2009.

PURPOSE: Recently, human papillomavirus (HPV) infection has been causally associated with a subset of head and neck cancers, particularly oropharyngeal cancer. As national cancer reporting systems typically report incidence rates of oropharyngeal cancer grouped with other cancers of the head and neck region, the objective of this study was to present age-standardized incidence trends in oropharyngeal cancer Canada-wide. METHODS: Data were obtained from the Canadian Cancer Registry for cases diagnosed between 1992 and 2009. Trends in age-standardized incidence rates were described for head and neck cancers overall and for HPV-associated oropharyngeal cancer using Joinpoint regression. RESULTS: The age-standardized incidence of head and neck cancers declined significantly in Canada from 1992 to 1998 (annual percentage change [APC] = -3.0, p < 0.01), then remained stable through to 2009. In contrast, the age-standardized incidence of HPV-associated oropharyngeal cancer increased significantly during the same time period, from 1.6 per 100,000 in 1992 to 2.6 in 2009 (APC = 2.7, p < 0.001). The increase in HPV-associated oropharyngeal cancer was greater in males than in females and increased significantly in all age groups, particularly those aged 50-59 (APC = 5.4, p < 0.001). The age-standardized incidence rate of head and neck cancer overall was stable or declined in all age groups except those aged 50-59 where incidence decreased from 1992 to 1997, then increased through to 2009. CONCLUSIONS: The incidence patterns of HPV-associated oropharyngeal cancer and head and neck cancer overall show contrasting trends. Findings highlight the need to surveil HPV-associated oropharyngeal cancer separately from other cancers of the head and neck region in order to monitor these emerging trends.

Associations of overall and abdominal adiposity with area and volumetric mammographic measures among postmenopausal women.

Whereas mammographic density and adiposity are positively associated with postmenopausal breast cancer risk, they are inversely associated with one another. To examine the association between these two risk factors, a secondary analysis of data from a randomized controlled trial of a year-long aerobic exercise intervention was done. Participants were 302 postmenopausal women aged 50-74 years. Dense fibroglandular and nondense fatty tissue were measured from mammograms using computer-assisted thresholding software for area measurements and a technique relying on the calibration of mammography machines with a tissue-equivalent phantom for volumetric measurements. Adiposity was measured by anthropometry (body mass index, waist circumference), whole-body dual x-ray absorptiometry scans (body fat) and computed tomography scans (abdominal adiposity). Correlations were estimated between and within women, the latter representing the association between the 1-year change in adiposity and mammographic measures. Adiposity was correlated with nondense area and volume (0.50 ≤ r ≤ 0.66 between women; 0.18 ≤ r ≤ 0.46 within women). Between women, adiposity was correlated with dense area and volume (-0.12 ≤ r ≤ -0.30) and with percent dense area and volume (-0.28 ≤ r ≤ -0.48). Because measurements made with scans explained at most only 3% more of the variation in absolute or percent density beyond that explained by anthropometric measurements, anthropometric measurements are likely sufficient for adjustment of the association between mammographic density and breast cancer risk. Adiposity is associated with breast fatty tissue and possibly weakly inversely associated with fibroglandular tissue.

Survival of metastatic colorectal cancer patients treated with chemotherapy in Alberta (1995-2004).

GOALS OF WORK: Clinical trials have suggested that advances in chemotherapy significantly improve the survival of patients with metastatic colorectal cancer. Comparable evidence from clinical practice is scarce. This study aims to investigate the survival of patients with metastatic colorectal cancer treated with chemotherapy in Alberta, Canada. PATIENTS AND METHODS: Trends of relative survival of patients diagnosed in 1994-2003 were assessed using Alberta Cancer Registry (ACR) data. The median overall survival (OS) of patients diagnosed in 2004 was determined by linking Cancer Registry data with Electronic Medical Records (EMR). Cox regression models were fitted to calculate the hazard ratio for patients treated with chemotherapy. RESULTS: The 2-year relative survival for patients with metastatic colorectal cancer who received chemotherapy increased significantly from 29% to 41% over the 10 years (1994-2003, p < 0.015). A 69% reduction in the risk of mortality was observed in the 168 patients who received chemotherapy compared to the 87 patients who did not, after adjusting for age, gender, and number of metastases. The median OS of patients who received chemotherapy was 17.5 months. This is comparable to the 18-20 months seen in recently published clinical trials, considering the patients in this study were from the real clinical practice, nearly half of them were older than 70, and many of them might have important co-morbidities. CONCLUSIONS: The survival of patients diagnosed with metastatic colorectal cancer in Alberta has improved in recent years; this is most likely attributable in large part to the use of chemotherapy.

Smoking frequency, prevalence and trends, and their socio-demographic associations in Alberta, Canada.

OBJECTIVES: To determine the numbers of smokers, smoking prevalence and trends, and to examine their socio-demographic associations in Alberta using data from three Canadian national health surveys undertaken between 2000 and 2005. METHODS: The three surveys collected self-reported health data from Canadians aged 12 years and older. The weighted number of smokers and the smoking prevalence by health region and by urban/rural status were determined. The socio-demographic associations of smoking in Alberta were examined using logistic regression analysis. RESULTS: The numbers of smokers and the smoking prevalence were both higher among men than women, in middle-aged groups (20-39 and 40-59 years) than in younger (12-19 years) and older (> or = 60 years) groups, and among Canadian-born people than immigrants to Canada. The smoking prevalence tended to 1) increase with the increasing rurality of residence, 2) decrease over the timeframe examined, 3) be inversely proportional to educational level and 4) be inversely proportional to household income. The number of smokers was largest in urban areas and among those who reported the highest education and household income. DISCUSSION: The new tobacco legislation being introduced in Alberta in 2009 may decrease the smoking prevalence in the province, but additional interventions in the regions with the largest numbers of smokers may help further reduce the smoking population and overall smoking prevalence in Alberta.

Prevalence, trend, and sociodemographic association of five modifiable lifestyle risk factors for cancer in Alberta and Canada.

OBJECTIVES: To examine the 12-year trend, in Alberta and Canada, of five modifiable lifestyle risk factors for cancer, and their associations with sociodemographic factors. METHODS: Six surveys collected data from Canadians aged > or =12 years. The prevalence, trends, and sociodemographic association of five lifestyle risk factors (smoking, inactivity, excessive drinking, overweight/obesity, and insufficient fruit/vegetable intake) were examined. RESULTS: Smoking and inactivity decreased significantly: by 5.4% and 2.7% (Alberta men) and 4.9% and 12.1% (Alberta women); by 7.5% and 8.5% (Canada men) and 7.7% and 11.9% (Canada women). Excessive drinking increased significantly: by 3.6% (men) and 0.9% (women), Alberta; by 2.5% (men) and 0.9% (women), Canada. Overweight/obesity significantly increased by 6.0% (Alberta) and 4.1% (Canada) in women. Being female, single, highly educated, or having higher income decreased the likelihood of exposure to multiple lifestyle risk factors; being middle aged, widowed/separated/divorced, or in poor health condition increased the likelihood. CONCLUSIONS: The downward trends for smoking and physical inactivity were in a direction that may help reduce cancer burden. The excessive drinking and overweight/obesity trends did not change in desired direction and deserve attention. The clustering of the lifestyle risk factors in specific social groups provides useful information for future intervention planning.

Sociodemographic, health and lifestyle characteristics reported by discrete groups of adult dietary supplement users in Alberta, Canada: findings from The Tomorrow Project.

OBJECTIVE: To determine the extent to which differences in sociodemographic, dietary and lifestyle characteristics exist between users of different types of dietary supplements and supplement non-users. DESIGN: We analysed cross-sectional data obtained from self-administered questionnaires completed at baseline by participants in The Tomorrow Project; a prospective cohort study in Alberta, Canada. Participants who used at least one type of dietary supplement at least weekly in the year prior to questionnaire completion were defined as supplement users, while the remainder were classified as non-users. Seven discrete user categories were created: multivitamins (+/- minerals) only, specific nutritional supplements only, herbal/other supplements only, and all possible combinations. Differences in sociodemographic, dietary and lifestyle characteristics between different groups of supplement users and non-users were analysed using Rao-Scott chi2 tests and multinomial logistic regression. SUBJECTS AND SETTING: Subjects were 5,067 men and 7,439 women, aged 35-69 years, recruited by random digit dialling throughout Alberta. RESULTS: Supplement use was extensive in this study population (69.8 %). Users of herbal/other supplements only, and women who used multivitamins only, tended to report dietary and lifestyle characteristics that were not significantly different from non-users. In contrast, those who reported using a combination of multivitamins, specific nutritional and herbal/other supplements were more likely than non-users to report behaviours and characteristics consistent with current health guidelines. CONCLUSIONS: Dichotomizing participants as supplement users or non-users is likely to mask further differences in sociodemographic, dietary and lifestyle characteristics among users of different types of supplements. This may have implications for analysis and interpretation of observational studies.

Low uptake of colorectal cancer screening 3 yr after release of national recommendations for screening.

BACKGROUND: National guidelines recommending colorectal cancer (CRC) screening for average risk Canadians were released in 2001. The current study determined rates of CRC screening and predictors of screening 3 yr after the guidelines were released. METHOD: A population-based random digit dial telephone survey of 1,808 Alberta men and women aged 50-74 yr assessed awareness about, and self-reported rates of, screening. RESULTS: More average risk women than men reported a recent screening with a home fecal occult blood test (FOBT) (14.0%vs 9.8%, P= 0.013) but men had slightly higher rates of screening endoscopy in the past 5 yr (4.3%vs 1.6%, P= 0.003). Overall, only 14.3% of average risk adults (N = 1,476) were up-to-date on CRC screening. Multivariable predictors of being up-to-date on CRC screening differed for men and women although a doctor's recommendation for screening was a strong predictor for both genders (men OR 5.0, 2.9-8.3, women OR 3.8, 2.3-6.5). Screening for other cancers was also an important predictor in both men and women. CONCLUSION: Three years after the release of national guidelines, rates of screening among average risk adults aged 50-74 yr were very low. Public education programs and primary care interventions to specifically invite average risk adults for screening may be required to increase CRC screening rates.

An analysis of the effect of selection bias on the association of hormone replacement therapy and breast cancer risk.

A sensitivity analysis was conducted to determine the impact on measures of effect of a suspected differential participation response rate between hormone replacement therapy (HRT) users and nonusers, among controls recruited to a population-based case-control study of breast cancer. The age-specific prevalence of current HRT use among controls was compared to data from the 1996 Canadian National Population Health Survey (NPHS). Control women identified as current HRT users were randomly re-sampled to replicate the prevalence of HRT use reported by the NPHS. Unconditional logistic regression was conducted to estimate odds ratios (OR) and 95 percent confidence intervals (CI) for the use of HRT and breast cancer risk before and after re-sampling. Multivariate adjusted ORs for breast cancer and estrogen-only and estrogen-progestin formulations were 0.76 (0.53-1.10) and 0.94 (95% CI: 0.64 - 1.38), respectively, using the original case-control controls and 0.99 (0.77-1.27) and 1.57 (95% CI: 1.02 - 2.40), respectively, following re-sampling of the controls. This sensitivity analysis illustrates the extent to which differential participation rates between HRT users and nonusers may affect estimates of measures of effect.

Colorectal cancer screening: practices and opinions of primary care physicians.

BACKGROUND: The Canadian Task Force on Preventive Health Care (CTFPHC), in 2001, concluded that there is good evidence to include annual or biennial fecal occult blood testing (FOBT) and fair evidence to include flexible sigmoidoscopy in the periodic health examination of asymptomatic adults more than 50 years of age. METHODS: Mailed survey of Alberta primary care physicians to determine current colorectal cancer (CRC) screening practices, familiarity with the new guideline, and opinions about, and barriers to, screening average-risk patients. RESULTS: Response rate was 58.0% (n = 965). Less than half (41.9%) were familiar with the new Canadian guideline. The majority (74.7%) recommended that asymptomatic patients undergo screening; however, only 35.6% offered screening to at least 75% of average-risk patients. Few (9.4%) rated fecal occult blood as an "excellent or very good" screening test. Most (64.1%) physicians would choose colonoscopy if they themselves were to undergo screening. Concerns were raised about cost-effectiveness, inconsistencies of current recommendations, and resources. CONCLUSION: Although supportive of colorectal cancer screening of average-risk patients, few physicians recommend screening for the majority of their patients. Clarification of inconsistencies between guidelines, resource issues, and the availability of efficacious screening tests is required for wider acceptance of the new Canadian guideline.

A retrospective study on the use of post-operative colonoscopy following potentially curative surgery for colorectal cancer in a Canadian province.

BACKGROUND: Surveillance colonoscopy is commonly recommended following potentially curative surgery for colorectal cancer. We determined factors associated with patients undergoing a least one colonoscopy within five years of surgery. METHODS: In this historical cohort study, data on 3918 patients age 30 years or older residing in Alberta, Canada, who had undergone a potentially curative surgical resection for local or regional stage colorectal cancer between 1983 and 1995 were obtained from the provincial cancer registry, ministry of health and cancer clinic charts. Kaplan-Meier estimates of the probability of undergoing a post-operative colonoscopy were calculated for patient, tumor and treatment-related variables of interest. RESULTS: A colonoscopy was performed within five years of surgery in 1979 patients. The probability of undergoing a colonoscopy for those diagnosed in the 1990s was greater than for those diagnosed earlier (0.65 vs 0.55, P < 0.0001). The majority of the difference was seen at one-year following surgery, consistent with changes in surveillance practices. Those most likely to undergo a colonoscopy were those under age 70 (0.74 vs 0.50 for those age 70-79, P < 0.0001), who underwent a pre-operative colonoscopy (0.69 vs 0.54, P < 0.0001), and who underwent a resection with reanastomosis (0.62 vs 0.47 for abdominoperineal resection, P < 0.0001) by a surgeon who performs colonoscopies (0.68 vs 0.54, P < 0.0001). CONCLUSIONS: The majority of patients undergo colonoscopy following colorectal cancer surgery. However, there are important variations in surveillance practices across different patient and treatment characteristics.

Prevalence of PSA testing and effect of clinical indications on patterns of PSA testing in a population-based sample of Alberta men.

An age-stratified population-based random digit dial (RDD) telephone survey determined awareness and prevalence of prostate-specific antigen (PSA) testing among Alberta men aged 40 74 years, and assessed the role of indications for PSA testing in explaining patterns of PSA testing. The sample of 1984 men (participation rate 65%) with no history of prostate cancer was divided into three age strata: 40-49, 50-59, and 60-74 years. Awareness of PSA tests was low with fewer than half of the men indicating they had ever heard of PSA tests. The percentage of men who had ever had PSA testing was 4.5%, 13.1%, and 22.2% in the three age strata respectively. PSA testing was strongly associated with having at least one clinical indication for PSA testing (prevalence 21.8%, 26.9%, and 42.2% respectively). PSA testing rates were very low among men who had no clinical indications for PSA testing, suggesting infrequent PSA screening prior to the survey. PSA testing patterns in this population-based sample were consistent with Alberta clinical practice guidelines.

Case-control study of anthropometric measures and breast cancer risk.

A population-based case-control study of 1,233 incident breast cancer cases and 1,241 controls was conducted in Alberta between 1995 and 1997 to examine the influence of anthropometric factors on the risk of breast cancer using several newly derived variables. Data on current height, weight and waist and hip circumference were collected by interviewers using standardized methods. Respondents recalled their body weight at each decade from age 20 to the referent year. Several variables were estimated, and unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). No statistically significant associations for any of the estimated variables with breast cancer risk for premenopausal women (462 cases, 475 controls) were found. The results for postmenopausal women (771 cases, 762 controls) in the highest vs. lowest quartiles were, for waist circumference, OR = 1.30 (95% CI 0.97-1.73); waist-hip ratio, OR = 1.43 (95% CI 1.07-1.93); weight gain since age 20, OR = 1.35 (05% CI 1.01-1.81); difference between maximum and minimum weights over adult lifetime, OR = 1.56 (95% CI 1.16-2.08); and the reference weight minus the minimum weight since age 20, OR = 1.47 (95% CI 1.10-1.97). Statistically significant trends in risk were observed for these variables. Effect modification with hormone replacement therapy use was found for most variables assessed for postmenopausal women, with much stronger associations found among never-users compared to ever-users. We found strong evidence that waist-hip ratio and weight gained over lifetime, as assessed by different variables, are postmenopausal breast cancer risk factors. These effects were independent of dietary intake and lifetime total physical activity.