Introduction
Colon cancer, encompassing malignant neoplasms of the colon excluding the rectum (C20) and anus, constitutes one of the most significant contributors to cancer-related morbidity and mortality worldwide. As a component of the broader colorectal cancer (CRC) spectrum, it represents approximately half of all CRC cases by anatomic site, with colon cancer accounting for 49.6% and rectal cancer 49.2% of CRC cases in China as a representative example 10. In 2022, the World Health Organization/International Agency for Research on Cancer estimated about 1.9 million new CRC cases and more than 900,000 deaths worldwide, making CRC the third most commonly diagnosed cancer and the second leading cause of cancer-related death globally 15. Understanding its epidemiology is essential for informing prevention, screening policy, and resource allocation across diverse healthcare settings.
Primary epidemiologic data sources informing this review include IARC GLOBOCAN (Cancer Today platform, 185 countries) 711, the IHME Global Burden of Disease (GBD) study (GBD 2023, covering 204 countries, 1990–2023) 1314, the WHO Mortality Database 15, the US Surveillance, Epidemiology, and End Results program (SEER) 1, European population-based cancer registries 8, and the National Central Cancer Registry of China (NCCR) 10. Rates are typically age-standardized to the World Standard Population (ASR per 100,000 person-years) to permit cross-national comparison.
Global and Regional Incidence and Prevalence
Table 1. Selected Age-Standardized Incidence and Mortality Rates for Colorectal Cancer by Region (most recent available data)
| Region / Country | ASIR (per 100,000) | ASMR (per 100,000) | Notes |
|---|---|---|---|
| United States | ~37.1 (2018–2022) | ~12.9 (2019–2023) | SEER; all CRC combined 1 |
| China (national) | 17.1 (2015) | 7.9 (2015) | NCCR registry sites 10 |
| China (urban) | >17.1 | >7.9 | Urban rates exceed national average 10 |
| China (rural) | <17.1 | <7.9 | Rising trend against national decline 10 |
| Europe (incidence highest) | High | Highest ASMR in Eastern Europe | WHO 2026 fact sheet 15 |
| Australia/New Zealand | High | Moderate | WHO; highest globally alongside Europe 15 |
| Sub-Saharan Africa (early-onset) | 1.2–1.6 per 100,000 | Low absolute | GBD 2019; lowest early-onset rates 3 |
| East Asia (early-onset) | ~12 per 100,000 | ~3.7 per 100,000 | GBD 2019; highest early-onset rates 3 |
Globally, colorectal cancer is the fourth most common cancer in the United States, representing 7.6% of all new cancer cases, with 154,270 new cases and 52,900 deaths projected for 2025 1. Incidence is consistently higher in males than females: in the US, male age-adjusted incidence is 42.3 per 100,000 versus 32.6 per 100,000 in females 1. Racial and ethnic disparities are pronounced; Non-Hispanic American Indian/Alaska Native populations exhibit the highest incidence rates (56.2 males; 45.6 females per 100,000), while Non-Hispanic Asian/Pacific Islander populations show the lowest (35.3 males; 25.6 females per 100,000) 1.
China, driven by its large population, accounted for 24% of all newly diagnosed cancer cases and 30% of cancer-related deaths worldwide in 2020 (GLOBOCAN 2020), despite ranking 65th globally by age-standardized incidence rate (ASIR 204.8 per 100,000 for all cancers combined) and 13th by age-standardized mortality rate 2. Within China, colorectal cancer ranked third in incidence among men and second among women, and gastrointestinal cancers collectively account for 45% of all cancer-related deaths 2. Incidence rates were highest in Europe and Australia/New Zealand, while Eastern Europe carried the highest mortality rates 15.
Stage at diagnosis significantly shapes the burden profile. In the US, 34% of cases are diagnosed at the localized stage (5-year survival 91.5%), 37% at the regional stage (74.6%), and 23% at the distant metastatic stage (16.2%), yielding an overall 5-year relative survival of 65.4% (2015–2021 data) 1. In European screening populations, screen-detected cancers present predominantly at stages I–II (65.6%) versus non-screen-detected cancers, where 56.4% are at stages III–IV 8.
Temporal Trends (2015–2025)
In high-income settings, overall CRC incidence in older adults has followed a long-term declining trajectory. In the United States, the age-adjusted incidence rate declined at an average annual percentage change (AAPC) of approximately 0.7% per year from 2013–2022, with mortality declining at 1.3% per year from 2014–2023 1. In China's urban areas, national incidence and mortality rates decreased by 10.2% and 9.5%, respectively, between 2009 and 2015, with annual percentage changes of −1.5% and −1.4% for urban sites 10. These trends likely reflect the combined impact of expanded screening, adenoma detection, and improved treatment.
A contrasting pattern is observed in rural China, where incidence increased by 20.0% and mortality by 15.2% over the same 2009–2015 period, with an AAPC of +3.3% for rural incidence, underscoring the divergence between urbanizing and underserved populations 10. Similar rising trajectories are anticipated across LMICs as westernization of diet and lifestyle accelerates.
Early-onset colon cancer (<50 years) has emerged as a critical trend. Globally, the incidence of early-onset CRC reached 225,736 cases in 2019, with an incidence rate of 5.7 per 100,000 person-years (95% UI: 5.3–6.3), representing a 64.3% increase in incidence rate from 1990 to 2019 3. In the US, incidence in the 40–49 age group increased by almost 15% from 2000–2002 to 2014–2016 12. East Asia (12 per 100,000), high-income Asia Pacific (12 per 100,000), and Australasia (11 per 100,000) exhibit the highest early-onset incidence rates, while Sub-Saharan Africa (1.2–1.6 per 100,000) shows the lowest 3. In Saudi Arabia, early-onset CRC incidence rose from 1.32 to 2.02 per 100,000 between 2001 and 2016 (AAPC +2.6%), with women aged 40–49 showing higher rates than men in the same group—a distinct demographic pattern 4. These trends prompted the USPSTF in 2021 to lower the recommended screening initiation age from 50 to 45 years 12.
Etiology and Risk Factors
Colon cancer etiology is multifactorial, encompassing modifiable lifestyle exposures and non-modifiable genetic determinants.
Modifiable risk factors associated with early-onset CRC DALYs globally in 2019 include diets low in milk (17% attributable fraction, 95% UI: 11–22%), diets low in calcium (17%, 11–19%), and alcohol use (10%, 7.7–13%) 3. High body mass index (7.9%), smoking (7.1%), diets high in red meat (5.3%), high fasting plasma glucose (2.9%), diets high in processed meat (2.5%), low dietary fiber (2.3%), and physical inactivity (1.6%) also contribute 3. Notably, the relative contributions of high BMI and high fasting plasma glucose increased substantially from 1990 to 2019 among both sexes, reflecting the global rise in obesity and type 2 diabetes, while smoking and low fiber ranked lower over time—particularly among females 3. The WHO confirms that high intake of processed and red meat, physical inactivity, obesity, tobacco use, and alcohol consumption are key risk factors 15. Gut microbiome dysbiosis and environmental exposures are emerging areas of research, as highlighted by the hypothesis that early prenatal-to-adolescent exposures may drive early-onset disease through epigenetic and microbiota-mediated mechanisms 5.
Non-modifiable risk factors include advancing age (median age at diagnosis: 66 years in the US) 1, male sex, family history, and hereditary syndromes. Lynch syndrome (caused by germline mutations in MMR genes), familial adenomatous polyposis (FAP/APC mutations), and MUTYH-associated polyposis are the principal hereditary causes and are identified by the WHO as key genetic risk factors 15. Biological pathways underlying sporadic colon cancer include chromosomal instability (CIN), microsatellite instability (MSI), and the CpG island methylator phenotype (CIMP); MSI-high tumors, associated with Lynch syndrome and a subset of sporadic cases, have distinct immunologic profiles relevant to immunotherapy responsiveness.
Protective factors include adequate dietary calcium and milk intake, physical activity, and possibly aspirin/NSAID use, though chemoprevention evidence must be weighed against gastrointestinal and cardiovascular risks 315.
Disease Burden: Mortality, DALYs, and Quality of Life
Global projections from GLOBOCAN 2020 anticipate a 49% increase in new cancer cases and a 62% increase in cancer deaths by 2040 compared with 2020, with China alone expected to reach 6.85 million new cancer cases and 5.07 million deaths in 2040 2. The GBD 2023 study provides downloadable DALY forecasts to 2050 13.
For colorectal cancer in China specifically, GBD 2017 data estimate DALYs at 4.254 million person-years in 2017—double the 1990 figure—accounting for 22.4% of global colorectal cancer burden 10. The decomposition of DALYs reveals that years lived with disability (YLD) contribute approximately 12% of total colorectal cancer DALYs in China, with years of life lost (YLL) constituting the dominant component, highlighting the predominantly fatal nature of the disease 9. Methodological limitations exist: GBD disability weights have been derived primarily from non-Chinese populations, potentially biasing regional DALY estimates 9.
In terms of survival outcomes, the 5-year relative survival rate in the US is 65.4% overall 1. European data from 16 cancer registries (9 countries; n=228,134) demonstrate that screen-detected colorectal cancers carry markedly superior 5-year overall survival (83.4%; 95% CI: 82.9–83.9) and cancer-specific survival (89.2%; 95% CI: 88.8–89.7) compared to non-screen-detected cases (57.5% and 65.7%, respectively) 8. Stage-specific 5-year overall survival for screen-detected cases ranges from 92.4% (stage I) to 32.3% (stage IV) 8.
Quality-of-life (QoL) instruments commonly applied in CRC populations include the EORTC QLQ-C30/CR29 and FACT-C, though detailed QoL outcome data were not retrieved in the available source materials. The economic burden is substantial: in China, one-year out-of-pocket expenditure for newly diagnosed colorectal cancer patients amounts to approximately 60% of their previous-year household income, with medical expenditure per patient growing at an annual rate of 6.9–9.2% 10.
Prevention and Screening Impact
Screening represents the primary lever for both incidence reduction (via adenoma detection and removal) and mortality reduction (via stage shift). The USPSTF 2021 updated guidance recommends:
| Age Group | Recommendation | Grade |
|---|---|---|
| 45–49 years | Screen for colorectal cancer | B (moderate net benefit) |
| 50–75 years | Screen for colorectal cancer | A (substantial net benefit) |
| 76–85 years | Individualized decision | C (small net benefit) |
Approved modalities include annual high-sensitivity guaiac fecal occult blood test (HSgFOBT) or fecal immunochemical test (FIT), stool DNA-FIT every 1–3 years, CT colonography every 5 years, flexible sigmoidoscopy every 5–10 years, and colonoscopy every 10 years 12. The lowering of the recommended screening age to 45 was explicitly motivated by the approximately 15% rise in incidence among adults aged 40–49 years from 2000–2002 to 2014–2016 12.
European data quantify the survival benefit of screening: screen-detected cases comprise 22.3% of cases in the target age group (60–69 years) across 16 registries, with stage I–II distribution of 65.6% versus 43.6% in non-screen-detected cases 8. The consequent survival advantage—over 25 percentage points in 5-year overall survival—underscores the population-level impact of organized screening programs. Colonoscopy enables direct adenoma removal, reducing incidence through polyp surveillance and resection.
Data Limitations and Methodological Notes
Several limitations constrain interpretation of the available data. First, registry completeness varies substantially across regions: Sub-Saharan Africa, South Asia, MENA, and rural China have lower registry coverage and data quality, potentially underestimating true incidence and mortality 310. Second, age-standardization differences (World Standard Population vs. other reference populations) affect cross-study comparability. Third, changes in diagnostic practice, coding revisions, and screening intensity over time can produce apparent trend artifacts; for example, increased screening may temporarily inflate incidence while simultaneously reducing mortality. Fourth, GBD small-area estimates incorporate modeled data in regions with sparse empirical registries, carrying wider uncertainty intervals 14. Fifth, the colon cancer subsite (ICD-10 C18) is not always disaggregated from rectal cancer (C20) in aggregate statistics, limiting precise subsite-specific analyses, particularly for older global datasets. Sixth, COVID-19-related disruptions to screening programs in 2020–2021 may have introduced diagnostic delays and reporting artifacts in trend analyses; no retrieved source provided quantified estimates of this effect. Finally, quality-of-life outcome data stratified by region and treatment modality were not available in the retrieved source materials, limiting synthesis on QoL instruments and population-level implications.
Conclusion
Colon cancer remains a major global health challenge, with an estimated 1.9 million combined CRC new cases in 2022, substantial regional heterogeneity in incidence and mortality, and a growing burden among adults under 50 years of age 153. High-income regions—particularly Europe, Australia/New Zealand, and North America—carry the highest incidence rates but benefit from organized screening and treatment, yielding lower mortality-to-incidence ratios compared to LMICs 1815. The divergence between declining urban rates and rising rural rates in countries like China highlights that economic development transitions carry complex epidemiologic consequences 10. Addressing modifiable risk factors—particularly obesity, physical inactivity, dietary patterns, and alcohol use—while expanding screening access to younger age groups and underserved populations, represents the most evidence-supported pathway to reducing colon cancer burden over the coming decade 31215.