Spatial epidemiologic analysis of the liver cancer and gallbladder cancer incidence and its determinants in South Korea

Background There have been reports on regional variation in prevalence of hepatitis B and C, and Clonorchis sinensis (C. sinensis) infection, which indicates potential of spatial variation in liver cancer and gallbladder cancer incidence in Korea. Therefore, we aimed to assess the regional variation of liver and gallbladder cancer incidence and its determinants based on the regional distribution of risk factors, including hepatitis B infection in Korea. Methods This study used an ecological study design and district-level cancer incidence statistics generated by the National Cancer Center. Spatial clusters of liver and gallbladder cancer incidence were detected based on spatial scan statistics using SaTScan™ software. We set the size of maximum spatial scanning window of 25 and 35% of the population at risk for analyses of liver and gallbladder cancer, respectively. Significance level of 0.05 was used to reject the null hypothesis of no cluster. We fitted the Besag-York-Mollie model using integrated nested Laplace approximations to assess factors that influence the regional variation in cancer incidence. Results Spatial clusters with high liver cancer incidence rates were detected in the southwestern and southeastern regions of Korea. High gallbladder cancer incidence rates are clustered in the southeastern region. Regional liver cancer incidence can be accounted for the prevalence of high household income (coefficient, − 0.10; 95% credible interval [CI], − 0.18 to − 0.02), marital status (coefficient, − 0.14; 95% CI, − 0.25 to − 0.03), the incidence of hepatitis B (coefficient, 0.87; 95% CI, 0.29 to 1.44), and liver cancer screening (coefficient, 0.06; 95% CI, 0.00 to 0.12), while gallbladder cancer incidence was related to the prevalence of high household income (coefficient, − 0.03; 95% CI, − 0.05 to 0.00) and living close to a river with a high prevalence of liver fluke infection (coefficient, 0.55; 95% CI, 0.14 to 0.96). Conclusions This study demonstrated geographic variation in liver and gallbladder cancer incidence, which can be explained by determinants such as hepatitis B, income, marital status, and living near a river.

Age-Specific Trend and Birth Cohort Effect on Different Histologic Types of Uterine Corpus Cancers

To evaluate the uterine corpus cancer incidence rates, age-specific trends and birth cohort patterns by different histologic types. From the Taiwan Cancer Registry, we identified women with a primary diagnosis of uterine corpus cancer (n=28 769) from1998 to 2017. We analyzed the incidences, stages of disease at diagnosis and prognostic factors in endometrioid and non-endometrioid carcinoma. During the study period, uterine corpus cancer incidence rates increased over time from 5.3 to 15.21 per 100 000 woman-years. Incidence trends for endometrioid carcinoma increased in all age groups and the rise was steeper in women age 40 years and younger. For non-endometrioid carcinomas, incidence rates increased in women over 50 years. Women diagnosed after 2013 had significantly better cancer-specific survival (CSS) (hazard ratio [HR] =0.81, 95% confidence interval [CI] 0.73-0.89) compared with those at the period of 2009-2012. CSS also improved in stage I (HR=0.81, 95% CI 0.49-0.63) and stage III (HR 0.90, 95% CI 0.58-0.72) endometrioid carcinomas after 2013. Whereas CSS remained unchanged for non-endometrioid carcinomas. We found the incidences of both endometrioid and non-endometrioid carcinomas continued to increase among contemporary birth cohorts. Etiologic research is mandatory to explain the causes for these trends.

Disparities in the Increases of Cervical Cancer Incidence Rates: Observations from a City-wide Population-based Study

Background: Globally cervical cancer incidence rate has been declining continuously. However, an unfavorable trend has been observed in China during the past decades, and the underlying reasons remain unclear. We hereby explore the recent trends of cervical cancer incidence, as well as the underlying determinants using data from Guangzhou, one of biggest cities in China. Methods：City-wide cancer registration data were obtained from the Guangzhou Center for Disease Prevention and Control from 2004 to 2018. We used the Joinpoint regression models to estimate the average annual percentage change (AAPC) of age-standardized and age-specific incidence rates by regions and by histological subtype. Age-period-cohort models were applied to analyze the period and birth cohort effects on the time trends. Results: The age-standardized rates (ASRs) of cervical cancer incidence increased at an annual rate of 2.1% [95% confidence interval (CI): 1.0%-3.2%] during 2004-2018. The largest increase in ASRs was found for rural regions, with AAPC of 6.6% [95% CI: 3.7%-9.5%], followed by the suburbs (2.2% [95% CI: 1.0%-3.4%]), while there was no statistically significant increase in urban regions. The ASRs of adenocarcinoma increased faster than those of the squamous cell carcinoma (AAPC=6.53% [95% CI: 5.0%-8.1%] versus 1.79% [95% CI: 0.8%-2.8%]). A downward trend in urban regions was found in the 20-49 age group, whereas an upward trend was found in the 50+ age group, especially in rural regions. An inverted V-shape was found for cohort effects, with the peak varied by regions, i.e., peaked in the 1966 and 1971 birth cohort in the urban and suburb regions, respectively. Period effects kept increasing during the study period. Conclusions: We systematically examine the disparities in the increases of cervical cancer incidence rates using city-wide data from Guangzhou. Extensive efforts are warranted to address the large urban-rural disparities in cervical cancer prevention. The combined strategies of vaccination, screening, and health education should be reinforced and locally customized.