Decreases in Smoking-Related Cancer Mortality Rates Are Associated with Birth Cohort Effects in Korean Men

Age-period-cohort effect on lung cancer mortality in Spain, 1982-2021

BACKGROUND

The aim of the study is to provide up-to-date information and evaluate the age-period-cohort effects of age-period cohorts on lung cancer (LC) mortality in Spain for the period 1982 to 2021.

METHODS

We analysed deaths by LC and population for the period 1982-2021, available from the Spanish National Institute of Statistics. The LC corresponds to code 162 and codes C33 and C34 of the 9th and 10th editions of the International Classification of Diseases, respectively. Age-period-cohort (A-P-C) modelling was applied to compute the net drift, local drift, longitudinal age curve, and rate ratios (RR) of each period and cohort. A-P-C analysis was performed using the A-P-C Web Tool provided by the National Cancer Institute of the United States.

RESULTS

Estimated relative risk in the male birth cohorts has followed a steady downward trend in all cohorts born since 1922, showing an initial period (1922-1947) of slight decline, followed by a more marked decrease in the cohorts born during the period 1947-1977. In the younger cohorts (1977-1997), the decline appears to have stabilised. In women, a strong cohort effect is observed. In those born after the Spanish Civil War (1936 to 1939), the risk increased until it peaked in the 1960s, after which it started to decrease with the same intensity. Period RR in men decreased from 1987 to 1991 (1.1) to 2017-2021 (0.6), while period RR in women increased during this time (from 0.8 to 1.6).

CONCLUSIONS

The cohort effect observed in women born after the Civil War suggests that the onset of the LC epidemic may have been due to a higher prevalence of women smokers in these cohorts. However, the trend observed in the younger cohorts suggests a possible slowing-down in the increase in mortality risk in the following years.

Trends in incidence and survival of esophageal cancer in Korea: Analysis of the Korea Central Cancer Registry Database

BACKGROUND AND AIM

The diagnostic and therapeutic modalities of esophageal cancer have recently improved in Asia, and its prognosis is expected to change. This study provides a population-based report on the epidemiology of esophageal cancer in Korea.

METHODS

Cancer incidence data from 1999 to 2013 were obtained from the Korea Central Cancer Registry, covering the entire population. Age-standardized incidence rates and annual percent changes were calculated according to subsites and histological types. Five-year relative survival rates were estimated for cases diagnosed between 1993 and 2013. Relative excess rates were compared between patients diagnosed from 2009 to 2013 and 2006 to 2008.

RESULTS

The age-standardized incidence rates decreased from 8.8 per 100 000 populations in 1999 to 5.9 in 2013 with an annual percent change of -2.6% in men and -2.2% in women. The most common histological type was squamous cell carcinoma, accounting for 90.2% of all esophageal cancers in 2013, followed by adenocarcinomas (3.1%), and their incidences decreased. The proportion of localized and regional cancer tended to increase compared with that of distant cancer. Five-year relative survival of squamous cell carcinoma improved from 12.1% (1993-1995) to 34.6% (2009-2013). Relative excess rate was 0.72 (95% confidence interval 0.65-0.80) in localized stage and 0.88 (95% confidence interval, 0.82-0.95) in regional stage comparing patients diagnosed from 2009 to 2013 and 2006 to 2008.

CONCLUSIONS

The incidence of esophageal cancer has decreased in Korea for the past 15 years, and 5-year survival rates have improved significantly. These increases may be attributable to more effective detection of early-stage disease.

Inequalities in esophageal cancer mortality in Brazil: Temporal trends and projections

The main objective of the study was to analyze the effect of age, period and birth cohort on esophageal cancer mortality in Brazil and its geographic regions, per sex. An ecological study is presented herein, which evaluated the deaths by esophageal cancer and the distribution, per geographic region. Poisson Regression was utilized to calculate the effects of age, period and birth cohort, and projections were made with the statistical software R, using the age-period-cohort model. Projection of data covered the period 2015–2029. Regarding the geographic regions of Brazil, a decrease was verified, throughout time, for the mortality rates of the South and Southeast regions, for men and women. For the North, Northeast and Midwest regions, an increase was evidenced in mortality rates, mainly for men, after the 2000's. Regarding the projections, a progressive increase of mortality rates was verified for the Northeast and North regions. Divergences evidenced for observed and projected esophageal cancer mortality rates revealed inequalities among the geographic regions of Brazil.

Incidence and survival of oropharyngeal cancer in Denmark: a nation-wide, population-based study from 1980 to 2014

BACKGROUND

Oropharyngeal carcinomas (OPCs) constitute a significant and increasing proportion of head and neck carcinomas and are an important global cause of morbidity and mortality. The purpose of this study was to determine trends in incidence and survival in OPC in the Danish population from 1980 to 2014.

METHODS

This study included all patients registered in the nationwide Danish Cancer Registry over the period 1980-2014. The age-adjusted incidence rates (AAIR) per 100,000, annual percentage change (APC) and average annual percent change (AAPC) were evaluated. Five-year relative survival (RS) was calculated with Cox regression analyses in relation to gender, anatomical location and histology.

RESULTS

A total of 6555 patients (69% male) were included, with a median age at diagnosis of 60 years. The AAIR of patients with OPC increased from 0.815 per 100,000 in 1980 to 4.51 per 100,000 in 2014 with an AAPC of 5.3. The 5-year RS increased significantly from 33.1% over the period 1980-1984 to 58.5% (25.4% points) over the period 2010-2014. With no significant difference stratified for gender. Tumors located at the palatine tonsils (n = 3333) and salivary gland OPC (n = 90) had significantly better survival compared with other sub-locations and histology subtypes. In the APC model the birth cohort effect rate ratio increased until 1925 and then decreased until 1935 from which point it increased in the last cohorts.

CONCLUSIONS

In this population-based study, we observed a significant increase in the incidence of OPCs and in the RS for OPC. We also identified a profound birth cohort effect on the incidence.