Mortality and Years of Life Lost of Colorectal Cancer in China, 2005–2020

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Mortality and Years of Life Lost of Colorectal Cancer in China, 2005–2020: Findings from the National Mortality Surveillance System

Colorectal cancer (CRC) has emerged as a significant public health challenge in China, ranking as the fourth leading cause of cancer-related deaths. A comprehensive analysis of CRC mortality trends and premature mortality burden from 2005 to 2020, utilizing data from China’s National Mortality Surveillance System (NMSS), reveals critical insights into the epidemiological patterns, regional disparities, and underlying drivers of CRC mortality. This study provides a detailed examination of national and provincial-level data, highlighting the urgent need for targeted interventions to mitigate the growing burden of CRC.

Data Sources and Methodological Framework

The study leveraged multi-source data from the NMSS, managed by the Chinese Center for Disease Control and Prevention (CDC). The NMSS covers over 300 million individuals across 605 surveillance points in 31 provincial-level administrative divisions (PLADs), representing approximately 24% of China’s population. Mortality data were adjusted for underreporting using field surveys conducted between 2006 and 2017. Underreporting rates (URRs) were calculated for each age-sex stratum, and spline regression was employed to predict URRs for years not covered by direct surveys (2005 and 2018). All-cause mortality rates were adjusted for underreporting and further refined using log-linear models and locally weighted regression to ensure continuity across surveillance points.

Cause-specific mortality for CRC (ICD-10 codes C18–C21.8) was estimated by redistributing nonspecific or implausible causes of death (“garbage codes”) using established methodologies. Age-standardized mortality rates (ASMRs) were computed using the 2010 national census population as a reference. Years of life lost (YLLs), a metric quantifying premature mortality, were calculated by multiplying the number of deaths by standard life expectancy at each age, derived from a theoretical minimum-risk reference life table.

To assess temporal trends, annual rates of change (ARCs) in age-standardized YLL rates were computed. Drivers of changes in CRC deaths—population growth, aging, and age-specific mortality rate shifts—were decomposed using Das Gupta’s demographic method, which accounts for interactions between these factors.

National Trends in CRC Mortality and Premature Burden

Between 2005 and 2020, the estimated number of CRC deaths in China increased by 59.79%, rising from 111,410 to 178,020. Despite this absolute increase, the age-standardized mortality rate (ASMR) declined marginally from 10.01 to 9.68 per 100,000 population, reflecting a 3.30% reduction. The age-standardized YLL rate, a measure of premature mortality burden, decreased by 10.20%, indicating progress in mitigating early CRC deaths.

Sex disparities were pronounced, with men consistently experiencing higher mortality than women. In 2020, male CRC deaths numbered 100,700 compared to 77,300 female deaths. The male ASMR (11.78 per 100,000) was 50% higher than the female rate (7.83 per 100,000). Similarly, age-standardized YLL rates for men (255.23 per 100,000) exceeded those for women (173.21 per 100,000).

Provincial Heterogeneity in CRC Mortality

Substantial geographical disparities were observed across China’s 31 PLADs. In 2020, the highest ASMRs were recorded in Fujian (15.50 per 100,000), Zhejiang (14.07), and Guangdong (13.05), while the lowest rates were in Tibet (3.93), Hebei (5.61), and Henan (5.90). Over the study period, 13 provinces experienced increases in ASMR, with Tibet showing the steepest rise (56.30%), whereas Hebei demonstrated the largest decline (-37.90%).

The distribution of premature mortality burden varied markedly. In economically developed regions like Shanghai, Beijing, and Zhejiang, over 70% of YLLs occurred among individuals aged ≥60 years. In contrast, Tibet exhibited a unique pattern, with nearly 40% of CRC-related YLLs occurring in individuals under 40 years. This divergence underscores the influence of regional socioeconomic factors, healthcare access, and lifestyle patterns on CRC outcomes.

Age and Sex-Specific Mortality Patterns

CRC mortality increased with age, peaking in individuals aged ≥80 years. In 2020, 70.73% of national YLLs were attributed to individuals aged ≥60 years. However, sex differences emerged in age-specific mortality: men had higher mortality rates across all age groups except the ≥80 cohort, where female rates slightly surpassed males.

Temporal trends in premature mortality burden revealed significant reductions among younger populations. The ARC for YLL rates in the 0–29 age group declined by 2.14% nationally, with Shanxi province achieving an 18.51% reduction. Conversely, older adults (≥75 years) experienced a 0.94% increase in YLL rates, highlighting the growing burden of CRC among aging populations.

Drivers of CRC Mortality Changes

Decomposition analysis identified population aging as the dominant driver of increased CRC deaths, contributing 55.84% to the national rise. Population growth accounted for 8.48%, while reductions in age-specific mortality rates offset 4.53% of the increase. Provincial variations were stark: population growth contributed most significantly to CRC death increases in Beijing (44.24%), Tianjin (42.52%), and Shanghai (39.39%), whereas population aging effects were highest in Ningxia (87.28%), Heilongjiang (86.65%), and Jilin (83.40%).

Age-specific mortality reductions were most pronounced in Hebei (-64.86%), Jiangxi (-43.43%), and Shanxi (-37.71%), reflecting successful localized interventions or healthcare advancements. Conversely, provinces like Gansu and Qinghai saw minimal mortality rate improvements, indicating unmet needs in CRC prevention and treatment.

Implications for Policy and Prevention

The study underscores the dual challenge of rising CRC deaths due to demographic shifts and persistent regional inequities. Key policy recommendations include:

  1. Lifestyle Modifications: Promoting diets rich in fiber, calcium, and dairy while reducing red meat consumption, alcohol use, and smoking—particularly among men, who face higher attributable risks.
  2. Expanded Screening Programs: Enhancing participation in CRC screening through fecal immunochemical tests (FIT) and colonoscopy, especially in high-burden provinces. Current screening uptake remains low (14% in urban programs), necessitating public awareness campaigns and healthcare infrastructure investments.
  3. Targeted Healthcare Resource Allocation: Prioritizing regions with limited resources, such as Tibet and western provinces, where younger populations face disproportionate premature mortality.
  4. Aging Population Strategies: Developing geriatric oncology guidelines to address multimorbidity and improve CRC management in elderly populations, who represent over 70% of YLLs.

Limitations and Future Directions

While the NMSS provides robust mortality data, potential underreporting and misclassification biases were mitigated through statistical adjustments. Projections for 2019–2020, based on pre-2018 trends, may not fully capture recent healthcare changes. Future research should integrate incidence data, treatment outcomes, and molecular epidemiology to refine risk stratification and intervention strategies.

In conclusion, this study provides a granular assessment of CRC mortality trends in China, emphasizing the need for tailored, province-specific interventions to address the evolving burden of colorectal cancer.

doi.org/10.1097/CM9.0000000000001625

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