Colorectal cancer screening is a critical preventative health measure for both men and women. Recommendations emphasize that individuals exhibiting symptoms suggestive of colorectal cancer or polyps should undergo diagnostic evaluation rather than screening. Effective screening programs begin with an assessment of an individual’s risk level, considering personal, family, and medical history to determine the most appropriate screening approach. For individuals at average risk, screening for colorectal cancer and adenomatous polyps is generally recommended to start at age 45. If a screening test yields abnormal results, a comprehensive examination of the colon and rectum, typically via colonoscopy, is advised.
Screening Recommendations for Average Risk Individuals
Starting at age 45, men and women at average risk for colorectal cancer should be offered one of the following screening options:
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Fecal Occult Blood Test (FOBT): Annual FOBT screening is recommended. This test requires examining two samples from each of three consecutive stools without rehydration. A positive result from any specimen necessitates a follow-up colonoscopy.
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Flexible Sigmoidoscopy: Flexible sigmoidoscopy every 5 years is another effective screening method.
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Combined FOBT and Flexible Sigmoidoscopy: A combined approach of annual FOBT with flexible sigmoidoscopy every 5 years is also a recommended option. When both tests are used, FOBT should be performed first.
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Colonoscopy: Colonoscopy every 10 years is a widely recommended screening modality.
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Double-Contrast Barium Enema (DCBE): DCBE every 5 years is an alternative screening option.
It’s important to note that in 2018, due to emerging data indicating increased colorectal cancer risks in individuals under 50, the American Society of Colon and Rectal Surgery updated their recommendations to consider initiating screening at age 45.
Assessing Increased Risk: The Role of 1st Degree Family
Individuals with a family history of colorectal cancer or adenomatous polyps are considered to be at increased risk. Specifically, having a 1st Degree Family relative (parent, sibling, or child) diagnosed with colon cancer or adenomatous polyps before the age of 60, or having two or more 1st degree family relatives diagnosed at any age, elevates your risk profile. This 1st degree family connection is a crucial factor in determining when and how you should begin colorectal cancer screening.
For those with such a 1st degree family history, screening recommendations differ significantly from those for average-risk individuals. It’s essential to discuss your 1st degree family history with your healthcare provider to determine the most appropriate screening plan.
Screening Recommendations for Increased Risk Groups
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Family History of Colorectal Cancer or Adenomatous Polyps: Individuals with a 1st degree family relative diagnosed with colorectal cancer or adenomatous polyps before age 60, or two or more 1st degree family relatives diagnosed at any age, should undergo colonoscopy screening more frequently and starting at a younger age than average-risk individuals. While specific guidelines may vary, starting colonoscopy screening at age 40, or 10 years younger than the earliest diagnosis in your 1st degree family, is often recommended, and repeated every 5 years.
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Familial Adenomatous Polyposis (FAP): Individuals with a genetic diagnosis of FAP, or those at risk for FAP without genetic confirmation, require annual sigmoidoscopy starting at ages 10 to 12. Genetic testing is advised for FAP patients with at-risk relatives. Genetic counseling is crucial for guiding genetic testing and colectomy decisions.
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Hereditary Nonpolyposis Colorectal Cancer (HNPCC) / Lynch Syndrome: Individuals with a genetic or clinical diagnosis of HNPCC, or at increased risk, should have colonoscopies every 1-2 years, beginning at age 20 to 25, or 10 years earlier than the youngest family member’s colon cancer diagnosis, whichever comes first. Genetic testing for HNPCC should be offered to 1st degree family relatives of those with known MMR gene mutations. It’s also recommended when modified Bethesda Criteria are met.
Surveillance for High-Risk Individuals
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History of Adenomatous Polyps: Individuals with a history of adenomatous polyps require follow-up colonoscopies. The timing depends on the initial findings, with shorter intervals for numerous, malignant, or large sessile adenomas. Those with advanced or multiple (>1cm) tubular adenomas should have their first follow-up colonoscopy within 5 years. Subsequent colonoscopy timing is based on follow-up findings.
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History of Colorectal Cancer: Post-curative resection for colorectal cancer, a colonoscopy is recommended around the time of diagnosis to rule out synchronous neoplasms. If preoperative obstruction occurred, colonoscopy can be done about 6 months post-surgery. If these examinations are normal, follow-up colonoscopies are advised after 3 years, and then every 5 years thereafter.
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Inflammatory Bowel Disease (IBD): Individuals with long-standing, extensive ulcerative colitis or Crohn’s colitis should consider surveillance colonoscopy with systematic biopsies due to increased cancer risk associated with IBD.
While newer screening technologies may emerge, current guidelines emphasize the importance of utilizing available screening methods now to prevent suffering and loss of life from colorectal cancer, the second leading cause of cancer death. Screening efforts will continue to improve with advancements in technology and clinical practice.
*Winawer S, Fletcher R, Rex D, Bond J, Burt R, et al. Colorectal Cancer Screening and Surveillance: Clinical Guidelines and Rationale-Update Based on New Evidence. Gastroenterology 2003;124:544-560.
