Study reveals complex patterns of burden and survival among people with digestive system cancers in China

Digestive system malignancies (DSMTs)-including esophageal, gastric, colorectal, liver, and pancreatic cancers-represent a major public health challenge in China. A recent national epidemiological study by Hu et al., published in eGastroenterology, analyzed trends from 2004 to 2021, revealing complex patterns of burden and survival. While progress has been made in reducing mortality from some cancers, the overall impact remains significant, with notable disparities across demographic and geographic lines. Below are the key findings:

Declining mortality from major DSMTs

Age-standardized mortality rates (ASMRs) for esophageal, gastric, and liver cancers significantly declined over the 18-year period: (i) esophageal cancer: ASMR declined with an average annual percentage change (AAPC) of −4.30%; (ii) Gastric cancer: ASMR decreased at an AAPC of −4.14%; (iii) Liver cancer: ASMR dropped with an AAPC of −2.58% . These improvements are attributed to enhanced public health policies, early screening programs, better control of risk factors like Helicobacter pylori (H. pylori) and hepatitis B virus, and socioeconomic development.

Rising burden of colorectal and pancreatic cancers

In contrast, colorectal and pancreatic cancers showed a troubling increase: (i) Colorectal cancer: Crude mortality rose with an AAPC of 3.59%; (ii) Pancreatic cancer: Both crude and age-standardised mortality increased, with AAPCs of 5.72% and 2.71%, respectively. These rises are partly linked to westernised diets, increased alcohol consumption, sedentary lifestyles, and late-stage diagnosis.

Life expectancy and cause-eliminated life expectancy (CELE) improved

Between 2004 and 2021, average life expectancy in China increased by 4.4 years. Importantly, when deaths from DSMTs were hypothetically eliminated, life expectancy (CELE) would rise by 4.06 years, underscoring the significant health impact of these cancers. The gains were more pronounced in rural areas and among men, suggesting improvements in health equity but also highlighting areas where further efforts are needed.

Gender, geographic, and socioeconomic disparities 

Men had consistently higher premature mortality, potential years of life lost (PYLL), and age-standardised mortality from DSMTs compared to women: (i) Total PYLL: 16.3 million person-years for men vs. 5.4 million for women; (ii) Average years of life lost (AYLL): 14.64 years for men vs. 13.52 years for women. These gaps reflect higher smoking and alcohol use among men and delayed health-seeking behaviours.

Rural residents bore a disproportionate burden: (i) Rural areas accounted for 15.1 million PYLL, more than twice that of urban areas (6.6 million); (ii) Pancreatic cancer ASMR rose steeply in rural areas (AAPC = 4.62%). Limited access to quality healthcare and later-stage diagnoses contribute to these outcomes.

Cancer burden varied widely by region: (i) Eastern regions showed significant reductions in esophageal, gastric, and liver cancers; (ii) Western regions, while improving, had higher AYLL values, indicating later diagnosis and poorer treatment access; (iii) Pancreatic and colorectal cancers increased more sharply in the west and central regions.

Contributing factors

(i) Screening and Early Detection: Government-led screening initiatives since 2005 have improved early diagnosis rates. Targeted programmes in high-incidence areas, including the Huaihe River Basin and Anyang, have been particularly effective for esophageal cancer. (ii) Vaccination and Risk Factor Control: The introduction of the hepatitis B vaccine into China's national immunisation programme in 2002 has played a key role in reducing liver cancer rates. Other improvements include better food safety, reduced aflatoxin exposure, and widespread H. pylori eradication. (iii) Westernization of Lifestyles: As economic conditions improved, dietary patterns shifted towards high fat, low fibre diets with increased meat consumption. These changes are linked to the rising incidence of colorectal and pancreatic cancers. Sedentary lifestyles, obesity, smoking, and alcohol abuse further exacerbate risk, especially in younger populations. (iv) Diagnostic Advances: Advancements in imaging technologies-CT, MRI, and nuclear magnetic resonance-have enhanced the detection of pancreatic cancer, though late presentation remains common.

In conclusion, while progress has been made in reducing mortality from several major digestive cancers, the rising burden of colorectal and pancreatic cancers, especially among rural and male populations, signals a shift in China's cancer epidemiology. Future efforts must focus on health equity, primary prevention, and early detection to sustain and expand recent gains in life expectancy. As China advances towards the goals of the "Healthy China 2030" initiative, comprehensive cancer control remains a cornerstone of public health advancement.