- A debate chaired by Dr Carmen Guerra, MD was conducted at the 2020 American Society of Clinical Oncology (ASCO) Gastrointestinal (GI) Cancers Symposium on whether the age to begin screening for colorectal cancer (CRC) should be lowered.
Why this matters
- Owing to increasing incidence of CRC among younger adults, the American Cancer Society in 2018 lowered the starting age for screening colonoscopy from 50 years to 45 years in average-risk individuals but not everyone agrees with the recommendation.
Catch them early
- Dr Uri Ladabaum, MD argued in the favor of earlier screening saying, "In life, 60 may be the new 40, but for colorectal cancer screening, 45 is definitely the new 50.”
- According to a 2017 study, individuals who were born around 1990 and later have double the risk for colon cancer and 4 times the risk for rectal cancer compared with those born circa 1950.
- A 2019 JAMA study showed that incidence of CRC increased significantly among adults aged 40-49 years from the 1990s through 2015, and the disease was diagnosed at later stages.
- A Taiwanese study found that the HR for detecting cancer in those with positive fecal immunochemical test results was higher in younger people than older people.
- A model estimated that nearly 4 CRCs would be averted in 1000 individuals with 1 to 2 CRC deaths by lowering the screening age.
- Dr Ladabaum believes the move would be cost-effective, considering about 30,000 CRCs and about 11,000 deaths can be prevented in the US with earlier screening.
Not so soon
- Dr David Weinberg, MD argued against earlier screening saying, "99.9% of people in their 40s will not develop colon cancer.”
- Although there has been a relative increase of 22% in the risk for CRC in younger people, it represents an absolute risk of just 1.3 more per 100,000 individuals.
- According to Dr Weinberg, models which calculate the risk and benefit of early screening may be beneficial for making decisions, but they do not define the standard of care.
- A 2019 study identified several nonmodifiable risk factors for early-onset disease other than age, including gender, race, history of inflammatory bowel disease, and family history of CRC. Thus, age cannot be the sole criteria for cancer stratification.
- Dr Weinberg also argues that although colonoscopy reduces the CRC mortality risk by about 75%, the procedure itself is associated with a mortality rate of 7 per 100,000 individuals.