BACKGROUND: Childhood leukemia (CL) is the most prevalent form of pediatric cancer on a global scale. However, there is a limited understanding of the dynamics of CL incidence in South America, with a specific knowledge gap in Colombia. This study aimed to identify trends in CL incidence and to analyze the effects of age, period, and birth cohort on the risk of leukemia incidence in this population.
METHODS: Information on all newly diagnosed leukemia cases (in general and by subtype) among residents aged 0-18 years and living in the serving areas of population-based cancer registries of Cali (2008-2017), Bucaramanga (2000-2017), Manizales (2003-2017), and Pasto (1998-2018). Estimated annual percent changes (EAPC) in incidence over time and potential changes in the slope of these EAPCs were calculated using joinpoint regression models. The effects of age, period, and cohort in CL incidence trends were evaluated using age-period-cohort models addressing the identifiability issue through the application of double differences.
RESULTS: A total of 966 childhood leukemia cases were identified. The average standardized incidence rate (ASIR) of leukemia was calculated and expressed per 100,000 person-years - observing ASIR of 4.46 in Cali, 7.27 in Bucaramanga, 3.89 in Manizales and 4.06 in Pasto. Concerning CL trends there were no statistically significant changes in EAPC throughout the different periods, however, when analyzed by leukemia subtype, statistically significant changes were observed in the EAPC for both ALL and AML. Analysis of age-period-cohort models revealed that age-related factors significantly underpin the incidence trends of childhood leukemia in these four Colombian cities.
CONCLUSIONS: This study offers valuable insights into the incidence trends of childhood leukemia in four major Colombian cities. The analysis revealed stable overall CL incidence rates across varying periods, predominantly influenced by age-related factors and the absence of cohort and period effects. This information is useful for surveillance and planning purposes for CL diagnosis and treatment in Colombia.

UNASSIGNED: Age-period-cohort (APC) analysis has been employed to differentiate long-term trends in the incidences of communicable diseases, including tuberculosis (TB), into the effects of age, birth year, and calendar period. However, no such study was hitherto conducted for Japan, which has 70 years of surveillance data. Therefore, we conducted APC analysis for TB in Japan.
UNASSIGNED: The national TB data for 1953-2022 were analyzed using the log-transformed linear model of APC analysis.
UNASSIGNED: Annual age-and sex-standardized notification rates of TB peaked at 599.0 per 100 000 population in 1955 and fell by 99% to 4.5 in 2022. Adjusting for the effects of the birth cohort and period, the relative age-effect risk of TB peaked at 20-29 years and went down toward 60-69 years. Regarding the birth cohort effect, the TB risk showed a turning point in approximately 1913 for the central years of birth. Another change appeared in 1963 when the decline of the risk slightly stagnated; then, it started declining again at a rate as fast as in 1923-1953. Period effects showed a hump in the late 1950s and early 1960s, then sharply declined to the late 1970s, and reached a near plateau level until 2022.
UNASSIGNED: Our results highlight the continuing peak in TB disease risk for young adults and sharp decrease in disease risk in the 1960s and 70s. The introduction of anti-TB drugs in the 1950s and early 1970s had the most important impact on the epidemiology of TB in Japan.

Globally, breast cancer is the leading cause of cancer deaths, accounting for 15.5% of female cancer deaths in 2020. Breast cancer is also the leading cause of female cancers in South Africa. The rapid epidemiological transition in South Africa may have an impact on the trends in breast cancer mortality in the country. We therefore evaluated the trends in the breast cancer mortality in SA over 20 years (1999-2020).
UNASSIGNED: Joinpoint regression analyses of the trends in crude and age-standardized mortality rates (ASMR) of breast cancer among South African women were conducted from 1999 to 2018 using mortality data from Statistics South Africa. Age-period-cohort regression analysis was then conducted to evaluate the independent effect of age, period, and cohort on breast cancer mortality, and analysis was stratified by ethnicity.
UNASSIGNED: The mortality rate of breast cancer (from 9.82 to 13.27 per 100,000 women) increased at around 1.4% per annum (Average Annual Percent Change (AAPC): 1.4%, 95% CI:0.8-2.0, P-value< 0.001). Young women aged 30-49 years (1.1%-1.8%, P-value< 0.001) had increased breast cancer mortality. The risk of breast cancer mortality increased among successive birth cohorts from 1924 to 1928 but decreased among recent cohorts born from 1989 to 1993. In 2018, the breast cancer mortality rate among Blacks (9.49/100,000 women) was around half of the rates among the non-Blacks. (Coloreds: 18.11 per 100,000 women; Whites: 17.77/100,000 women; Indian/Asian: 13.24 per 100,000 women).
UNASSIGNED: Contrary to the trends in high- and middle-income countries, breast cancer mortality increased in South Africa especially among young women. Breast cancer prevention programs should be intensified and should also target young women. The marked disparity in ethnic burden of breast cancer should be considered during planning and implementation of interventions.

BACKGROUND: Scotland has disproportionately high rates of suicide compared with England. An analysis of trends may help reveal whether rates appear driven more by birth cohort, period or age. A \'birth cohort effect\' for England & Wales has been previously reported by Gunnell et al. (B J Psych 182:164-70, 2003). This study replicates this analysis for Scotland, makes comparisons between the countries, and provides information on \'vulnerable\' cohorts.
METHODS: Suicide and corresponding general population data were obtained from the National Records of Scotland, 1950 to 2014. Age and gender specific mortality rates were estimated. Age, period and cohort patterns were explored graphically by trend analysis.
RESULTS: A pattern was found whereby successive male birth cohorts born after 1940 experienced higher suicide rates, in increasingly younger age groups, echoing findings reported for England & Wales. Young men (aged 20-39) were found to have a marked and statistically significant increase in suicide between those in the 1960 and 1965 birth cohorts. The 1965 cohort peaked in suicide rate aged 35-39, and the subsequent 1970 cohort peaked even younger, aged 25-29; it is possible that these 1965 and 1970 cohorts are at greater mass vulnerability to suicide than earlier cohorts. This was reflected in data for England & Wales, but to a lesser extent. Suicide rates associated with male birth cohorts subsequent to 1975 were less severe, and not statistically significantly different from earlier cohorts, suggestive of an amelioration of any possible influential \'cohort\' effect. Scottish female suicide rates for all age groups converged and stabilised over time. Women have not been as affected as men, with less variation in patterns by different birth cohorts and with a much less convincing corresponding pattern suggestive of a \'cohort\' effect.
CONCLUSIONS: Trend analysis is useful in identifying \'vulnerable\' cohorts, providing opportunities to develop suicide prevention strategies addressing these cohorts as they age.