Screening for high risk
The criteria for defining high-risk most commonly includes ages between 50-74 and other criteria based on clinical practice guidelines, such as family history.
However, many screening programs do not monitor individuals at high risk. Some screening registries have similar screening recommendations for increased risk and high-risk individuals, and high or increased risk individuals may still be reached through population-based screening programs intended for individuals at average risk.
Definitions of high risk for colorectal cancer
|Definition of high risk
|Starting at age 50, or 10 years earlier than the age their relative was diagnosed with colorectal cancer, whichever comes first
|People who are asymptomatic and have a family history of colorectal cancer that includes one or more first-degree relatives (parent, sibling, or child) who has been diagnosed with the disease.
|50 – 74
|Based on clinical guidelines
|50 – 74
|Based on Clinical Practice Guidelines-refer to specialist
|10 years prior to diagnosis of first degree relative
|50 – 74
|Those with personal / family history can begin screening with colonoscopy at 40.
|50 – 74
|The program does not intentionally recruit individuals at high risk for FIT screening. High risk individuals can access colonoscopy screening through their healthcare provider.
|50 – 74
|The program does not intentionally recruit individuals at high risk for FOBT screening. High risk individuals can access colonoscopy screening through their healthcare provider.
|Depends on family history or genetic syndromes
|High risk: People with hereditary colon cancer syndromes, such as familial adenomatous polyposis (FAP), Lynch syndrome, MUTYH-associated polyposis, Peutz-Jeghers syndrome and juvenile polyposis syndrome.
People who are at high risk are managed outside of the screening program.
|Based on Clinical Practice Guidelines. High risks definition is not specified in our guidelines. Guidelines definitions use the term of average risk and not-average risk.
|Depends on genetic syndrome
|High risk individuals should access colonoscopy through their healthcare provider.
|Depends on genetic conditions:
HNPCC – Start age of 20 or 10 years younger than affected relative
FAP – Start age between 10 and 12
AFAP – Start age between 16 and 18
|Increased risk definition in guidelines includes High risk individuals with a genetic condition (HNPCC, FAP, AFAP) with a predisposition to colorectal cancer. The specific condition determines the screening process, interval and age.
High risk individuals are not identified by the program. Individuals 50-74 with any increased risk are invited by invitation letter to self-identify their condition and discuss screening option with primary care provider (colonoscopy).
|50 – 74
|High risk individuals should access colonoscopy through their health care provider.
QC: *The algorithms for risk-based monitoring and management and clinical monitoring depending on the condition are currently under review. They currently have 3 risk categories: moderate risk, slightly increased risk and moderately increased risk. People at high risk are included in the moderately increased risk algorithms, but they do not have a specific definition or precise algorithm for this category.
-No information was provided at the time the data were collected.
Recommendations for individuals at high risk of colorectal cancer
|Screening recommendation for high-risk population
|Follow-up recommendation after normal colonoscopy
|· Participants with high risk adenoma(s) identified are recalled for colonoscopy in 2-3 years
· Participants with a strong family history are referred at age 40 years or 10 years prior to index case, whichever comes first
· Participants with a personal history of adenomas who have high risks polyp(s) identified are recalled for colonoscopy in 2-3 years
|· Participants after a normal colonoscopy are recalled for colonoscopy in 5 years FIT test not recommended
· Participants with a strong family history and normal colonoscopy are recalled for colonoscopy in 5 years, FIT test not recommended
· Participants with a personal history of adenomas and normal colonoscopy are recalled for colonoscopy in 5 years. FIT test not recommended.
|Refer to specialist
|Refer to specialist (out of Territory) for tailored screening
|As per specialist recommendations
|As clinically indicated
|FIT is not recommended; guidelines are “refer directly to colonoscopy”
|Screening through colonoscopy
|Colonoscopy every 5-10 years starting at age 40 or 10 years earlier than the youngest relative’s diagnosis.
|The program does not currently have recommendations for screening people at high risk of colon cancer due to hereditary colon cancer syndromes. People who are at high risk should not be screened with FIT and should talk to their doctor about how and when to get screened. *
|See NB Clinical Practice Guidelines for not-average risk screening.
|High risk with family history suggesting inherited cancer syndrome:
Genetics testing and follow high risk screening guidelines based upon genetics
|HNPCC – Colonoscopy screening
FAP – Sigmoidoscopy screening
AFAP – Colonoscopy screening
|HNPCC – repeat colonoscopy every 1 to 2 years
FAP – repeat annually sigmoidoscopy
AFAP – repeat annually colonoscopy
ON: *Ontario’s Ministry of Health provides funding for genetic testing for Lynch syndrome based on criteria set by the Ministry. Ontario Health (Cancer Care Ontario) also provides funding to select labs in the province to perform reflex testing to screen for Lynch Syndrome in patients under 70 years of age with invasive colorectal cancer (CRC) and endometrial cancer tumours.