Colorectal cancer (CRC) is a leading cause of morbidity and mortality in Canada. CRC screening and other factors associated with early-stage disease can improve CRC treatment efficacy and survival. This study examined factors associated with CRC stage at diagnosis among male and female adults using data from a large prospective cohort study in Alberta, Canada. Baseline data were obtained from healthy adults aged 35–69 years participating in Alberta’s Tomorrow Project. Factors associated with CRC stage at diagnosis were evaluated using Partial Proportional Odds models. Analyses were stratified to examine sex-specific associations. A total of 267 participants (128 males and 139 females) developed CRC over the study period. Among participants, 43.0% of males and 43.2% of females were diagnosed with late-stage CRC. Social support, having children, and caffeine intake were predictors of CRC stage at diagnosis among males, while family history of CRC, pregnancy, hysterectomy, menopausal hormone therapy, lifetime number of Pap tests, and household physical activity were predictive of CRC stage at diagnosis among females. These findings highlight the importance of sex differences in susceptibility to advanced CRC diagnosis and can help inform targets for cancer prevention programs to effectively reduce advanced CRC and thus improve survival.

Early detection of breast cancer improves survival, so identifying factors associated with stage at diagnosis may help formulate cancer prevention messages tailored for higher risk women. The goal of this study was to evaluate associations between multiple potential risk factors, including novel ones, measured before a breast cancer diagnosis and stage at diagnosis in women from Alberta, Canada. Women enrolled in Alberta's Tomorrow Project completed health and lifestyle questionnaires on average 7 years before their breast cancer diagnosis. The association of previously identified and novel predictors with stage (I, II and III + IV) at diagnosis were simultaneously evaluated in partial proportional odds ordinal (PPO) regression models. The 492 women in this study were predominantly diagnosed in Stage 1 (51.4%), had college or university education (75.4%), were married or had a partner (74.6%), had been pregnant (90.2%), had taken birth control pills for any reason (86.8%), and had an average body mass index of 26.6. Most had at least one mammogram (83%) with five mammograms the average number. Nearly all reported previously having a breast health examination from a medical practitioner (92.5%). Statistically significant factors identified in the PPO model included protective ones (older age at diagnosis, high household income, parity, smoking, spending time in the sun during high ultraviolet times, having a mammogram and high daily protein intake) and ones that increased risk of later stage at diagnosis (a comorbidity, current stressful situations and high daily caloric intake). Shifting breast cancer stage at diagnosis downwards may potentially be achieved through cancer prevention programs that target higher risk groups such as women with co-morbidities, non-smokers and younger women who may be eligible for breast cancer screening.

Prostate cancer (PCa) stage at diagnosis is an important predictor of cancer prognosis. In Canada, over one-quarter of males are diagnosed with advanced-stage PCa. Studies have identified several factors associated with PCa stage at diagnosis; however, evidence from Canada is limited. This study aimed to examine associations between sociodemographic characteristics, health history, health practices, and psychosocial factors and PCa stage at diagnosis among males participating in Alberta’s Tomorrow Project (ATP), a prospective cohort in Alberta, Canada. The study included males aged 35–69 years who developed PCa until January 2018. Factors associated with PCa stage at diagnosis were examined using partial proportional odds (PPO) ordinal regression models. A total of 410 males were diagnosed with PCa over the study period. A higher number of lifetime prostate-specific antigen tests were associated with earlier-stage PCa (OR 0.91, = 0.02, 95% CI 0.83–0.99), while higher abdominal circumference (OR 1.02, = 0.05, 95% CI 1.00–1.03), lower social support (OR 2.34, < 0.01, 95% CI 1.31–4.17), and having children (OR 2.67, < 0.01, 95% CI 1.38–5.16) were associated with later-stage disease. This study identified factors previously found in the literature as well as novel factors associated with PCa stage at diagnosis, which can help inform targets for cancer prevention programs to improve PCa prognosis.

Background/Objectives: Early-stage breast cancer treatments adversely affect components of health-related fitness (HRF) important for treatment tolerability, recovery, and long-term outcomes. Few studies have examined cancer treatment modality-specific effects on HRF. We examined associations of breast cancer treatment modalities, regimens, and combinations with one-year changes in HRF. Methods: Newly diagnosed early-stage breast cancer patients were recruited between 2012 and 2019 for the Alberta Moving Beyond Breast Cancer (AMBER) cohort study. HRF assessments were completed within 90 days of diagnosis and at one year, including cardiorespiratory fitness, muscle strength and endurance, and body composition. Analysis of covariance was used to test whether HRF changes differed between treatment modalities, regimens, and combinations. All tests were 2-sided. Results: A total of 1350 participants (mean [SD] age, 55.6 [10.7] years) were included. Women who received chemotherapy (n = 797; 59%) experienced statistically significant smaller increases in upper body strength (−1.7 kg, 95% confidence interval [CI]: −3.0 to −0.5), greater declines in lower body endurance (−118.0 kg, 95%CI: −216.6 to −19.3), and greater declines in total lean mass (−0.7 kg, 95%CI: −1.1 to −0.3), bone mineral density (−0.01 g/cm², 95%CI: −0.02 to 0.00), and bone mineral content (0.04 kg, 95%CI: −0.06 to −0.02). Other treatment modalities were modestly and inconsistently associated with HRF changes. Treatment combinations that included chemotherapy had the most negative impact on cardiorespiratory fitness and body composition. Conclusions: Chemotherapy—either alone or in combination with other treatments—had the largest and broadest negative impact on HRF recovery in early-stage breast cancer at one-year follow-up.

Risk prediction models for cancer stage at diagnosis may identify individuals at higher risk of late-stage cancer diagnoses. Partial proportional odds risk prediction models for cancer stage at diagnosis for males and females were developed using data from Alberta’s Tomorrow Project (ATP). Prediction models were validated on the British Columbia Generations Project (BCGP) cohort using discrimination and calibration measures. Among ATP males, older age at diagnosis was associated with an earlier stage at diagnosis, while full- or part-time employment, prostate-specific antigen testing, and former/current smoking were associated with a later stage at diagnosis. Among ATP females, mammogram and sigmoidoscopy or colonoscopy were associated with an earlier stage at diagnosis, while older age at diagnosis, number of pregnancies, and hysterectomy were associated with a later stage at diagnosis. On external validation, discrimination results were poor for both males and females while calibration results indicated that the models did not over- or under-fit to derivation data or over- or under-predict risk. Multiple factors associated with cancer stage at diagnosis were identified among ATP participants. While the prediction model calibration was acceptable, discrimination was poor when applied to BCGP data. Updating our models with additional predictors may help improve predictive performance.

Background: Breast cancer is the most common cancer in Canadian women; nearly 25% of women diagnosed with cancer have breast cancer. The early detection of breast cancer is a major challenge because tumours often grow without causing symptom. The diagnosis of breast cancer at an early stage (stages I and II) improves survival outcomes because treatments are more effective and better tolerated. To better inform the prevention of and screening for breast cancer, simulations using modifiable rather than non-modifiable risk factors may be helpful in shifting the stage at diagnosis downward. Methods: Breast cancer stages were simulated using the data distributions from Alberta’s Tomorrow Project participants who developed breast cancer. Using multivariable partial proportional odds regression models, modifiable lifestyle factors associated with the stage of cancer at diagnosis were evaluated. The proportions or mean levels of these lifestyle factors in the simulated population were systematically changed, then multiplied by their corresponding estimated odds ratios from the real data example. The effects of these changes were evaluated singly as well as cumulatively. Results: Increasing total dietary protein (g/day) intake was the single most important lifestyle factor in shifting the breast cancer stage downwards followed by decreasing total dietary energy intake (kcal/day). Increasing the proportion of women who spend time in the sun between 11 am and 4 pm in the summer months, who have had a mammogram, who have been pregnant or reducing the proportion who are in stressful situations had much smaller effects. The percentage of Stage I diagnoses could be increased by approximately 12% with small modifications of these lifestyle factors. Conclusion: Shifting the breast cancer stage at diagnosis of a population may be achieved through changes to lifestyle factors. This proof of principle study that evaluated multiple factors associated with the stage at diagnosis in a population can be expanded to other cancers as well, providing opportunities for cancer prevention programs to target specific factors and identify populations at higher risk.