Age-Related Trends

Incidence and mortality are increasing in younger patients. Although there are changes in risk factors associated with lifestyle, environment, and metabolic factors, the exact correlation is not established.1 In adults with CRC who are less than 50 years of age, a higher proportion present with primary tumors located in the distal colon and rectum.2 Since 2010, rates have increased for distant-stage disease by about 3% per year in this age group, which is associated with the lowest 5-year survival rate.3

By 2030, nearly 1 in 4 of rectal cancers and more than 1 in 10 of colon cancers will be diagnosed in people younger than 504

In 2021, the US Preventive Services Task Force recommended CRC screening beginning at age 45 years for average-risk individuals (Grade B)5,a

The incidence of CRC among younger adults has nearly doubled; in contrast, incidence has significantly decreased in older adults since the 1990s, when population-based screening for CRC was adopted2

TRENDS IN CRC INCIDENCE RATES BY AGE AND YEAR OF BIRTH, AND BY AGE AND YEAR OF DIAGNOSIS, US, 1975-20146

CRC Incidence Rates by Year of Birth

CRC incidence rates per 100,000 by year of birth, ranging from 1890 to 1990. Trend of decreasing CRC incidence for those aged 55+, while there is a steady increase in incidence for those aged 20-54 years old.

CRC Incidence Rates by Year of Diagnosis

CRC incidence rates per 100,000 by year of diagnosis, ranging from 1975 to 2014. Trend of decreasing CRC incidence for those aged 55+, while there is a steady increase in incidence for those aged 20-54 years old
  • Younger birth cohorts carry an elevated risk of developing CRC with age6
  • Incidence rates for colon cancer began increasing in the mid-1990s for adults aged 40-49 (1.3%/year) and is >2x the rate for adults aged 50-54 years (0.5%/year)6
  • A 2.3%/year increase in rectal cancer incidence rates began in the 1990s in adults aged 40-54 years7
  • A retrospective cohort analysis of SEER data from 1974-2013 found that adults born ~1990 have 2x the risk of colon cancer and 4x the risk of rectal cancer compared with adults born ~1950, who have the lowest risk7

Potential Contributing Factors to Onset Before Age 501

Donut chart depicting percentages of potential factors that can contribute to colorectal cancer onset before age 50. Figure shows approximately 59% is attributable to lifestyle, environmental, and metabolic factors, around 25% is attributable to family history of colorectal cancer, and around 16% is attributable to germline predisposition to cancer.
  • Approximately 16% of CRC in patients younger than 50 years is associated with a germline genetic predisposition to cancer; another 20-25% of cases are associated with family history of CRC, and the remaining cases are sporadic1
  • Early-onset CRC in adults <50 years is associated with primary tumors in the distal colon or rectum compared to older populations in whom proximal colon tumors predominate2
  • Learn more about pathobiology in younger patients with CRC

Delay-Adjusted CRC Incidence Rate, Ages <50 years1,8,b

Line graph depicting delay-adjusted colorectal cancer incidence rate in individuals aged <50 years between the years 2000 to 2016. Graph shows a steady trend of increasing incidence.
  • There’s been a ~51% increase in CRC incidence among those <50 years old from 1994 to 20146
  • There’s been an 11% increase in CRC mortality among those <55 years old from 2005 to 20156
  • More than 50% of adults younger than 50 years present with advanced disease3,9,c

CRC Incidence Rates per 100,000 Population in 1-Year Age Increments in the US Surveillance, Epidemiology, and End Results (SEER) 18 Registries Among Patients Aged 30-60 Years, 2000-201510,d

Line graph depicts colorectal incidence rates per 100,000 population in 1-year age increments in the United States. Graph tracks patients aged 30 to 60 years old between 2000 to 2015, as per SEER database. Graph shows an upwards trend as age increases. Noticeable increase in the trendline, incidence rate increase of 46.1%, from 49-50 years of age.
  • 46.1% increase in the incidence of CRC in the SEER 18 registries were found from 49 to 50 years of age10
  • The study investigators interpreted this 1-year jump as most likely indicating cancers that began before age 50 but went undetected due to the absence of screening prior to that age10
  • 8799 of the 9474 cases (92.9%) of CRC in the SEER 18 registries from 2000 to 2015 that were diagnosed among individuals aged 50 years were invasive10

Related Topics

Footnotes

  1. The USPSTF concludes with moderate certainty that screening for CRC in adults aged 45-49 years has moderate net benefit (Grade B).
  2. SEER Incidence Data, November 2022 Submission (1975-2020), SEER22 registries. Rates are per 100,000 and are age-adjusted to the 2000 US Standard Population (19 age groups - Census P25-1130).
  3. Younger patients were more likely to have primary rectal cancer (vs colon tumors) than those aged 50 years or older (40.0% vs 28.5%; P<0.0001) and were more likely to have stage III (28.1% vs 23.1%; P<0.0001) or stage IV disease (23.5% vs 16.9%; P<0.0001).
  4. Increase in incidence rate at age 50 is confounded by the recommendation to begin average risk of screening at this age.

List of definitions

CRC: colorectal cancer; SEER: Surveillance, Epidemiology, and End Results; US: United States; USPSTF: United States Preventive Services Taskforce.


References

  1. Patel SG, Boland CR. Colorectal cancer in persons under age 50: seeking causes and solutions. Gastrointestin Endosc Clin N Am. 2020;30:441-455.
  2. Stoffel EM, Murphy CC. Epidemiology and mechanisms of the increasing incidence of colon and rectal cancers in young adults. Gastroenterol. 2020;158:341-353.
  3. ACS. Colorectal cancer facts and figures 2023-2025. Atlanta: American Cancer Society; 2023.
  4. Bailey CE, Hu CY, You YN, et al. Increasing disparities in age-related incidence of colon and rectal cancer in the United States, 1975-2010. JAMA Surg. 2015;150(1):17-22.
  5. Davidson KW, Barry MJ, Mangione CM, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(19):1965-1977.
  6. Wolf AMD, Fontham ETH, Church TR, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society. CA Cancer J Clin. 2018;68(4):250-281.
  7. Siegel RL, Fedewa SA, Anderson WF, et al. Colorectal cancer incidence patterns in the United States, 1974-2013. J Natl Cancer Inst. 2017;109(8):djw322.
  8. Surveillance, Epidemiology, and End Results Program, National Cancer Institute. Colon and Rectum, Recent Trends in SEER Age-Adjusted Incidence Rates, 2000-2020. SEER*Explorer. Updated November 16, 2023. Accessed March 26, 2024. https://seer.cancer.gov/statistics-network/explorer/
  9. Virostko J, Capasso A, Yankeelov TE, et al. Recent trends in the age at diagnosis of colorectal cancer in the US National Cancer Data Base, 2004-2015. Cancer. 2019;125(21):3828-3835.
  10. Abualkhair WH, Zhou M, Ahnen D, et al. Trends in incidence of early-onset colorectal cancer in the United States among those approaching screening age. JAMA Netw Open. 2020;3(1):e1920407.