Comparison of Trends in Cancer Incidence and Mortality in Osaka,Japan, Using an Age-Period-Cohort Model

Background. We aimed to estimate the effects of age, period and birth cohort on trends in cancer incidenceand death for all sites and selected sites of cancer in Osaka using an age-period-cohort model. Methods. Cancerincidence data during 1968-2003 were obtained from the Osaka Cancer Registry, and cancer mortality withpopulation data in Osaka during 1968-2007 were obtained from vital statistics departments. We estimated age,period and birth cohort effects for incidence and mortality using Nakamura’s Bayesian Poisson age-periodcohortmodel. Results. For most sites of cancer, linear ageing effects were observed, the exceptions being breastand cervix which levelled-off at around 40 years old, while period effects were small. Decreasing cohort effectswere observed in stomach and liver cancer. Cohort effects peaked at the generation born in the early 1950sfor colorectal, lung, breast cancers. For most sites of cancer, incidence and mortality showed similar trends,but in the late cohorts for cervical cancer, cohort effects decreased in mortality, while increasing in incidence.Conclusion. Period effects reflecting immediate effects to cancer incidence and mortality, such as developmentof the effective treatment and screening programme were stable in most sites of cancer. Cohort effects influencedby long-term risk factors were prominently observed for every site, decrease in stomach and liver cancer casesbeing related to reduction in risk factor prevalence. Cancer control activities could be evaluated through theresults, indicating utility for future cancer control planning.     

Weight change in adulthood and risk of postmenopausal breast cancer: the HUNT study of Norway

Background:

Adult weight gain is associated with increased risk of postmenopausal breast cancer. Most previous studies are limited by using recalled or self-reported data, and it is not known if age-specific weight changes are important for breast cancer risk.

Methods:

In a Norwegian cohort of 28 153 women (and 900 incident breast cancers) with longitudinal anthropometric measurements over up to 30 years, we studied both overall and age-related weight changes in adulthood and risk of postmenopausal breast cancer.

Results:

Overall, weight gain in adulthood was associated with increased breast cancer risk (hazard ratio (HR) per kg per year 1.31, 95% confidence interval (CI) 1.11–1.54). Weight gain before (HR per kg per year 1.38, 95% CI 1.09–1.75) or around menopause (1.69, 95% CI 1.32–2.16) was associated with increased risk, but there was no clear risk increase associated with later weight gain (HR per kg per year 0.92, 95% CI 0.73–1.18).

Conclusion:

Weight gain in adulthood was associated with increased risk of breast cancer. Our results suggest that weight gain before and around menopausal age may be particularly important for breast cancer risk among postmenopausal women.     

Secular trends in cardiovascular risk factors: an age-period cohort analysis of 698,954 health examinations in 181,350 Austrian men and women

OBJECTIVES: It is well established that morbidity and mortality patterns in cardiovascular diseases vary strongly over time, yet the determinants of such trends remain poorly understood. To assess the potential contribution of secular or cross-generation patterns, we evaluated birth cohort-related trends across the 20th century of risk factors in a large database of Austrian men and women. SUBJECTS AND SETTING: Trends in risk factors were investigated for 181,350 adults aged 20-79 years born between 1905 and 1975 undergoing 698,954 health examinations between 1985 and 2005 as participants of the Vorarlberg Health Monitoring and Promotion Programme. RESULTS: There was clear evidence of cohort-related shifts in all risk factors. Total serum cholesterol and triglyceride declined markedly, particularly in the youngest cohorts, as did systolic and diastolic blood pressure in both men and women. By contrast, fasting glucose showed a strong rising tendency in both sexes and at all ages, most markedly in young males. Average glucose levels were between 4 and 15 mg dL(-1) higher in individuals at the same age born 20 years later. In males, body weight expressed in kg m(-2) (body mass index) was increasing as well; however, in women, patterns were most marked at the 90th percentile. CONCLUSION: These findings provide strong evidence of population wide secular shifts and suggest that in addition to period influences, most probably through treatment intervention and lifestyle change, determinants across the life-course are programming shifts from childhood onwards.