Malignant Tumors of the Central Nervous System in Kazakhstan: Component Analysis of Incidence Dynamics

Thyroid Cancer in Kazakhstan: Component Analysis of Incidence Dynamics

Background: The International Agency for Research on Cancer (IARC) reports that 567,000 new cases of thyroid cancer (TC) were registered in the world in 2018, and the age-standardized incidence rate was 6.7 per 100,000. The Global Cancer Observation forecasts a 35% growth in the number of new cases worldwide by 2040. The number of patients with TC in Kazakhstan is also increasing steadily. This investigation was the first epidemiological study of TC trends by component analysis among the population of Kazakhstan. This paper presents the results of the component analysis of TC incidence trends in Kazakhstan. Methods: The study covers primary data of TC cases (ICD 10 – C73) registered throughout Kazakhstan from 2009 to 2018. TC incidence trends were evaluated using component analysis according to the methodological recommendations. Results: 5,559 new TC cases were registered during the 10-year study period. The average age of patients was 52.0±0.2 years, the average annual age-standardized rate in 2009-2018 was 3.3±0.20/0000, with a constant upward trend (Т=+6.6%). According to the component analysis results, the increase in incidence was mainly due to the combined effect of the two factors: the increased disease risk (ΔR=+61.7%), and the population growth (ΔP=+15.4%). Conclusion: The noted increase in incidence was mainly caused by the changes in risk factors, such as the worsening environmental aspects and the increase in detection of clinically non-manifesting cases. The results of the study shall be taken into account when planning anticancer activities for TC.

Trends in the incidence of primary malignant brain tumors in Taiwan and correlation with comorbidities: A population-based study

OBJECTIVE

Primary malignant brain tumors are relatively uncommon, and their incidence and survival rates have seldom been reported.

PATIENTS AND METHODS

We identified all patients with malignant brain tumors in Taiwan between 1997 and 2012 using the National Health Insurance database. We estimated the stratified incidence of malignant brain tumors by age and sex. We estimated the median 1-, 2-, and 5-year survival, taking comorbidities into account. Trends for incidence and survival were analyzed using Joinpoint regression. The incidence in different geographic areas was also evaluated.

RESULTS

A total of 7746 men and 5846 women were identified. The incidence of malignant brain tumor was 3.34 (95% CI, 3.09-3.59) per 100,000 person-years in 1997 and 3.82 (95% CI, 3.56-4.08) per 100,000 person-years in 2012. The average annual percentage change (APC) of the standardized incidence over this period was 0.1 (95% CI, -1.9 to 2.2), suggesting a relatively stable incidence. However, the incidence significantly decreased between 1999 and 2012, with an APC of -1.8 [95% CI, -2.5 to -1.0]. One- and 5-year survival was 53.8% (50.0%-57.5%) and 27.5% (24.1%-30.9%) in 1997 and 67.6% (64.3%-70.7%) and 32.8% (29.6%-35.9%) in 2012. The average APC was 1.1 (95% CI, 0.7-1.5) for 1-year survival and 0.2 (95% CI, -1.0-1.4) for 5-year survival. The trend of improvement in the survival rate was seen for short-term but not long-term survival, especially in the group with more comorbidities.

CONCLUSIONS

A slightly decreased trend in incidence of primary malignant brain tumors was observed in Taiwanese general population since 1999. Over the past 15 years, the short-term survival of malignant brain tumors has improved, especially in adults.