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Colorectal Cancer Screening: Prevention and Early Detection Efforts

Learn about the importance of colorectal cancer screening, risk factors, family history implications, and screening tests available. Get insights into why screening is crucial in preventing the second leading cause of cancer death in the U.S.

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Colorectal Cancer Screening: Prevention and Early Detection Efforts

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  1. Colon Cancer Screening Loyola GI Susanne Shokoohi MD

  2. Colon Cancer Second leading cause of cancer death in the U.S. 1 in 3 who get it will die of it 20% of colon cancer in US diagnosed when it has already metastasized Colonoscopy most used screening test (61%)

  3. Ideal Disease for Screening • Disease is prevalent: 140,250 new cases in 2018 • Presence of precursor lesion • Tubular adenoma: precursor of 70% of CRC • Serrated lesions: 30% • Test/treatment available to detect and treat precursor lesion or early cancer

  4. Epidemiology

  5. Percent of Adults Age 50-75 up to date with Colorectal Cancer Screening 2016 • Nationwide 67% in 2016 • 1/3 of adults not screened as recommended

  6. Why do we care? 10-15 years

  7. Polyp Shapes

  8. Paris Classification

  9. Types of polyps • Adenomatous polyps • By definition, all adenomas are dysplastic. • Tubular, tubulovillous, villous adenomas. • Villous adenomas are associated with more severe degrees of dysplasia. • Low grade dysplasia vs high grade dysplasia (includes carcinoma in situ). • Serrated polyps – serrated pathyway • Hyperplastic polyps – no increased risk of cancer.

  10. Mechanism of carcinogenesis • Adenoma-Carcinoma Hypothesis • Generally accepted that colon cancers originate within previously benign adenomas and serrated polyps. • Progression from adenoma  carcinoma results from accumulation of mutations. • Tumor initiation: Formation of the adenoma. • Tumor progression: Progression of the adenoma to carcinoma.

  11. Risk Factors Nonmodifiable risk: Male gender, age > 50, AA race, genetics/family history

  12. Risk Factors

  13. Gender and CRC Screening • Women have a lower age-adjusted risk of CRC and advanced adenoma • Lag time of 7-8 years • CRC risk • 50 year old Man = • 58 year old Woman • Hormonal delay of CRC from menopause Levin et al. Gastroenterology 2008; 134: 1570-1595

  14. Race and CRC Screening • African Americans have higher CRC incidence and mortality • Access to care reduced • Failure of physicians to recommend screening • Biologic/genetic predisposition • Many groups (such as ACG) recommend screening for African Americans starting at age 45 Levin et al. Gastroenterology 2008; 134: 1570-1595

  15. Family History • Possible hereditary syndrome if • CRC <50 • multiple family members with CRC • Familial Polyposis • Lynch Tumors • Uterine, gastric, ovarian, small bowel, pancreas Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  16. Family History

  17. Familial Adenomatous Polyposis (FAP) • Autosomal Dominant • Polyps appear at age 16 • Average age of colon cancer is 39 • Increased risk for small intestine and gastric cancers, and other types of cancer • Treatment: surveillance, colectomy

  18. Lynch Syndrome= HNPCC • Autosomal dominant • Earlier age of CRC onset ~ 45 years • Higher rates of synchronous CRC • Risk of endometrial, ovarian cancers, bladder, stomach, small bowel, • Treatment- colectomy, hysterectomy

  19. Prognosis www.Cancer.org

  20. Screening Justification • Major health problem • Effective therapy exists • Sensitive/specific screening test • Cost effective Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  21. GIE 2017, Am J Gastro 2017, Gastroenterol 2017

  22. Who to Screen • Average risk (no family history, no symptoms): age 50 • African Americans: age 45 • Family history: • Documented first degree relative with colon cancer or advanced adenoma age < 60 years OR • Two first degree relatives with these findings at any age • Colonoscopy q 5 years, beginning 10 years prior to diagnosis or age 40, whichever is earlier • What to do when the patient reaches 60

  23. CRC Screening Based on Family History Levin et al. Gastroenterology 2008; 134: 1570-1595

  24. Colon Cancer: Not decreasing for everyone • Incidence of CRC in adults younger than 50 is increasing • More than a tenth (11% of colon and 18% of rectal cancer) occur at age < 50 • More likely to present with advanced disease Kristin Freiborg, age 22. New York Times, February 28, 2017

  25. Age < 50 Age > 50

  26. SEER Study: 1975-2010 • By 2030, incidence rate will increase by 90% in 20-34 year old age group • Compared with adults born around 1950, those born in 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer • Young patients more commonly have symptomatic, later stage, mucinous, and poorly differentiated tumors • Should screening begin at 40? So far no change in recommendations

  27. Screening Tests Structural tests Stool based tests • Barium Enema • CT Colonography • Sigmoidoscopy • Colonoscopy • Fecal Occult Blood Testing (FOBT) • Fecal Immunochemical Testing (FIT) • Fecal DNA testing Levin et al. Gastroenterology 2008; 134: 1570-1595 Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  28. FOBT • Detection of occult blood in the stool through a chemical reaction (looks at peroxidase activity). • One stool sample not adequate (3 samples from 3 consecutive BMs) • Convenient, easy to use, cheap • Interval: annual • Decreased mortality • 15-33% • Downsides: Can be falsely positive due to diet: red meat, vitamin C (> 250 mg daily), NSAIDs. • Positive FOBT should not trigger consult for GI bleed! Levin et al. Gastroenterology 2008; 134: 1570-1595 Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  29. FOBT Red meat Broccoli Turnips Cauliflower Radishes Cantaloupe Iron supplements Aspirin NSAIDs Less sensitive for proximal colon Only 1 specimen Specimen hydration Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  30. FIT(Fecal Immunochemical Testing) • Uses antibodies directed against human hemoglobin • One stool sample • Annual testing • Hemoglobin in upper GI tract is broken down by time reaches colon thus not detected by FIT • No diet or drug restrictions • Preferred form of FOBT in screening guidelines Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  31. FIT Test • One sample. Paper that goes across rim of toilet, poop on that, poke poop a few times with applicator and put in collection tube, mail it in. • $22 • Recommended annually

  32. Cologuard • Combination of FIT test plus DNA analysis of cells shed from polyps and tumors • Collection kit with two sample containers (one for FIT, one for DNA, only need one poop) • No dietary modification • Store at room temperature, mail within 72 hours • ~$600

  33. Pivotal study • 9,989 average risk patients who received FIT and Cologuard, followed by colonoscopy1 • NNT (number need to screen to detect one cancer): • Colonoscopy 154 • Cologuard 166 • FIT 208 1. Imperiale T et al. Multi-target stool DNA testing for colorectal cancer screening. NEJM 2014;370:1287-1297.

  34. Performance Characteristics

  35. Positive Cologuard: What Happens With Colonoscopy • Study of patients with positive cologuard • Compared colonoscopy findings when the endoscopist knew cologuard was positive versus not knowing • More adenomas/SSAs found in the unblinded group (70% vs 53%, p =0.013) and advanced neoplasms (28% vs 21%, p=NS) Johnson, D et al. GIE 2017;85:657-665.

  36. Capsule Colonoscopy • Approved by FDA for imaging the proximal colon in patients with prevous incomplete colonoscopy • Patients who need colorectal imaging but are not candidates for colonoscopy or sedation

  37. Capsule Colonoscopy • Not approved for screening average risk people • Extensive bowel prep required • 88% sensitive for adenoma > 6 mm • Ineffective for serrated lesions • 9% of pts in rigorous study had inadequate bowel prep

  38. Colonoscopy • Gold-standard • Reduces cancer and mortality • Direct mucosal inspection of the entire colon Levin et al. Gastroenterology 2008; 134: 1570-1595 Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  39. Polyps

  40. Colon Cancer

  41. Risks of Colonscopy • Sedation • Bleeding • Range from 0.2-10% for polypectomy • Can be delayed up to 2 weeks • Perforation • Approximately 1 in 2,000-10,000 Colonoscopy: Principles and Practice. 2nd edition Edited by Jerome D. Waye, Douglas K. Rex and Christopher B. Williams. 2009 Blackwell Publishing Ltd. Levin et al. Gastroenterology 2008; 134: 1570-1595

  42. Bowel Preparation

  43. Colonoscopy Limitations • Requires a bowel preparation • Usually perceived as most unpleasant part • Usually done with sedation • Patients need transportation • Miss a day of work • Requires a chaperone • Operator dependent • Missed lesions • Small but present risks Levin et al. Gastroenterology 2008; 134: 1570-1595 Bresalier and Robert S. Sleisenger and Fordtran's Gastrointestinal and Liver Disease 2016. 2248-2296

  44. Colonoscopy Intervals Levin et al. Gastroenterology 2008; 134: 1570-1595

  45. Surveillance Guidelines Assumption • Baseline exam was of high quality; good prep and everything removed completely • Monitor adenoma detection rates and withdrawal times • ADR benchmark is currently > 25% overall, >30% for males and > 20% for females • Higher ADR = more protective • Kaminiski M et al. NEJM 2010;362:1795-1803 • Baxter N et al. Gastroenterol 2011;140:65-72

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