National and Subnational Population-Based Incidence of Cancer in Thailand: Assessing Cancers with the Highest Burdens

Abstract

In Thailand, five cancer types-breast, cervical, colorectal, liver and lung cancer-contribute to over half of the cancer burden. The magnitude of these cancers must be quantified over time to assess previous health policies and highlight future trajectories for targeted prevention efforts. We provide a comprehensive assessment of these five cancers nationally and subnationally, with trend analysis, projections, and number of cases expected for the year 2025 using cancer registry data. We found that breast (average annual percent change (AAPC): 3.1%) and colorectal cancer (female AAPC: 3.3%, male AAPC: 4.1%) are increasing while cervical cancer (AAPC: -4.4%) is decreasing nationwide. However, liver and lung cancers exhibit disproportionately higher burdens in the northeast and north regions, respectively. Lung cancer increased significantly in northeastern and southern women, despite low smoking rates. Liver cancers are expected to increase in the northern males and females. Liver cancer increased in the south, despite the absence of the liver fluke, a known factor, in this region. Our findings are presented in the context of health policy, population dynamics and serve to provide evidence for future prevention strategies. Our subnational estimates provide a basis for understanding variations in region-specific risk factor profiles that contribute to incidence trends over time.

Keywords: Thailand; health policy; incidence; projections; trends.

Figure 1

Breast, cervix, colorectal, liver and lung cancers combined had the highest age-standardized rates in 2012 and accounted for more than half of the incidence, prevalence and mortality in Thailand. *excluding non-melanoma skin cancer.

Figure 2

Population distribution for each region and nationally in 2012 and the expected population distribution in 2025.

Figure 3

National and subnational average annual percent changes (AAPC) of each cancer from 2000 to 2012 for females and males. Significant AAPC are denoted with an asterisk (*). Significance was achieved at α = 0.05.

Figure 4

National and subnational estimates for incidence of the top five cancers combined for females and males.

Figure 5

Incidence trends for each cancer by region and sex. Note: Different Y-axis range for each sex.

Figure 6

Standardized rate ratios (SRRs) and their 95% confidence intervals comparing incidence of each region to national estimates (SRR = 1) from 2000 to 2012. Solid lines for confidence intervals indicate significant SRRs and were only highlighted if SRRs were significant for all years. Significance was achieved at α = 0.05.

Figure 7

Projections of cancer trends for males and females by cancer

Figure 8

Age-specific incidence rates for each cancer in females only by region. Note the Y-axis are different for each cancer.

Figure 9

Age-specific incidence rates of each cancer in males only by region. Note the Y-axis are different for each cancer.

Figure 10

The Thai Cancer Information Network houses data from six high-quality cancer registries that were used to estimate subnational burdens of cancer as shown.