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Rectal CA pp

Rectal CA pp






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  • 17. Site Distribution At one time, conventional wisdom held that half of all colorectal tumors could be reached with the examining finger, or at least the rigid sigmoidoscope. This reflects the distal predominance of colorectal cancer, whose distribution roughly corresponds to that of adenomas. A gradual shift toward a more proximal distribution may be occurring. Whether this is due to improved detection of right-sided tumors, to a change in dietary carcinogen-related exposure of the mucosa, or to other factors, is unknown. •  Vukasin AP, Ballantyne GH, Flannery JT, et al: Increasing incidence of cecal and sigmoid carcinoma. Data from the Connecticut Tumor Registry. Cancer, 66:2442-9, 1990. • Shinya Y, Wolff WI: Morphhology, anatomic discribution, and cancer potential of colonic polyps. Ann Surg, 190:679-83, 1979.

Rectal CA pp Rectal CA pp Presentation Transcript

  • Colorectal Cancer Bruce D. Greenwald, MDAssociate Professor of Medicine University of Maryland School of Medicine
  • Outline• Where is the colon and what does it do?• Why is colon cancer important? • How many cases/year? • Who gets it? • Who dies from it?• How does colon cancer develop?• How is colon cancer treated?• Is colon cancer preventable?
  • 2003 Estimated US Cancer Cases* Men Men WomenProstate 222,849 210,816 Breast 675,300 675,300 658,800Lung/bronchus 94,542 79,056 Lung/bronchusColon/rectum 74,283 72,468 Colon & rectumUrinary bladder 40,518 39,528 Uterine corpusMelanoma of 27,012 26,352 Ovary skin 26,352 Non-HodgkinNon-Hodgkin 27,012 lymphoma lymphoma 19,764 Melanoma ofKidney 20,259 skinOral cavity 20,259 19,764 ThyroidLeukemia 20,259 13,176 PancreasPancreas 13,506 13,176 Urinary bladderAll other sites 114,801 62,238 All other sites ONS=Other nervous system. *Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder. Source: American Cancer Society, 2003.
  • 2003 Estimated US Cancer Deaths* Men WomenLung/bronchus 88,629 67,650 Lung/bronchus 285,900 270,600Prostate 28,590 40,590 BreastColon & rectum 28,590 29,766 Colon & rectumPancreas 14,295 16,236 PancreasNon-Hodgkin 11,436 13,530 Ovary lymphoma 10,824 Non-HodgkinLeukemia 11,436 lymphomaEsophagus 11,436 10,824 LeukemiaLiver/intrahepatic 8,577 8,118 Uterine corpus bile duct 5,412 Brain/ONSUrinary bladder 8,577 5,412 Multiple myelomaKidney 8,577 62,238 All other sitesAll other sites 62,898 ONS=Other nervous system. *Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder. Source: American Cancer Society, 2003.
  • Ethnic/Gender Differences Incidence per 100,000 Survival (%) 40 100 35 80 30 63 53 25 60 20 15 40 10 20 5 0 0 Women Men African-American WhiteSource: Surveillance, Epidemiology, and End Results Program, 1973-1999, Division of Cancer Controland Population Sciences, National Cancer Institute, 2002.
  • Colon cancer rates for Baltimore City and Maryland, 1994-1998 70 60 Baltimore City 50 Maryland 40 30 20 10 0 Overall Men Women African- White AmericanSource: Maryland Department of Health and Mental Hygience. Annual Cancer Report. September, 2001. Age-adjusted incidence per 100,000 population
  • How Does Colorectal Cancer Develop?Janne PA, Mayer RJ. N Engl J Med 2000;342:1960.
  • Colon Polyp
  • Colon Cancer
  • How Does Colorectal Cancer Develop?Janne PA, Mayer RJ. N Engl J Med 2000;342:1960.
  • Symptoms of Colorectal CancerTime Course Symptoms FindingsEarly None None Occult blood in stoolMid Rectal bleeding Rectal mass Change in bowel Blood in stool habitsLate Fatigue Weight loss Anemia Abdominal mass Abdominal pain Bowel obstruction
  • Staging of Colorectal Cancer
  • Frequency of Colorectal Cancer by Dukes Stage
  • Survival by Dukes Stage
  • Treatment of Colorectal Cancer by Stage
  • Is Colorectal Cancer Preventable? YES!• Screening• Chemoprevention
  • Screening Techniques for Colorectal Cancer Fecal occult blood test (FOBT) every year, or Flexible sigmoidoscopy every 5 years,or A fecal occult blood test every year plus flexible sigmoidoscopy every 5 years (recommended by the American Cancer Society), or Double-contrast barium enema every 5 to 10 years, or Colonoscopy every 10 years (recommended by the American College of Gastroenterology).
  • Screening For Colon Cancer SAVES LIVES!!! MortalityTest ReductionFecal occult blood testing 33%Flexible sigmoidoscopy 66%(in portion of colon examined)FOBT + flexible sigmoidoscopy 43%(compared to sigmoidoscopy alone)Colonoscopy ~76-90%(after initial screening and polypectomy)
  • Colorectal cancer screening First assess RISKAVERAGE RISK INDIVIDUAL• All patients age 50 years and older, the asymptomatic general populationHIGH RISK• Personal history – polyp or cancer• Family history – polyp or cancer in first degree relatives
  • Why aren’t more people screened for colon cancer? Reasons for refusal of fecal occult blood testing • Fear of further testing and surgery • Feeling well • Unpleasantness of stool collection procedure But: • Strongest predictor of whether a patient will be screened = physician encouragementHynam et al. J Epidemiol Comm Health 1995;49:84Mandelson et al. Am J Prevent Med 2000;19:149
  • Fecal Occult Blood Testing• Examination of stool for occult (“hidden”) blood• Can detect one teaspoon or less of blood in a bowel movement• Uses chemical reaction between blood and reagent
  • FOBT improves survival Years after diagnosis
  • Trends in FOBT, 1997-2001 30 25 20 1997 Prevalence (%) 15 1999 10 2001 5 0 Total Men Women Less than High High School Some college School graduate or greaterSource: Behavioral Risk Factor Surveillance System, 1996-1997, 1999, 2001, National Center for Chronic DiseasePrevention and Health Promotion, Centers for Disease Control and Prevention and Prevention, 1999, 2000, 2002.
  • Double-contrast Barium Enema
  • Double-contrast Barium Enema• Pros • Examines entire colon • Relatively low cost• Cons • Never studied as a screening test • Missed 50% of polyps > 1cm in one study • Detects 50-75% of cancers in those with positive FOBT • Interval between exams unknownWinawer et al. Gastroenterology 1997; 112:599Rex, Endoscopy 1995; 27:200Lieberman et al. N Engl J Med 2000; 343:163
  • Sigmoidoscopy/Colonoscopy
  • Site Distribution
  • Flexible sigmoidoscopy • Pros • May be done in office • Inexpensive, cost-effective • Reduces deaths from rectal cancer • Easier bowel preparation, usually done without sedation • Cons • Detects only half of polyps • Misses 40-50% of cancers located beyond the view of the sigmoidoscope • Often limited by discomfort, poor bowel preparationSelby et al N Engl J Med 1992; 336:653 Stewart et al Aust NZ J Surg 1999; 69:2Newcomb et al. JNCI 1992; 84:1572 Painter et al Endoscopy 1999; 3:269Rex et al. Gastrointest Endosc 1999; 99:727
  • Colonoscopy• Pros • Examines entire colon • Removal of polyps performed at time of exam • Well-tolerated with sedation • Easier bowel preparation, usually done without sedation• Cons • Expensive • Risk of perforation, bleeding low but not negligible • Requires high level of training to perform • Miss rate of polyps < 1 cm ~25%, > 1 cm ~5%Rex et al. Gastroenterology 1997; 112:24-8Postic et al. Am J Gastroenterol 2002; 97:3182-5
  • Colonoscopy
  • Chemopreventive agentsFiber Not effectiveAspirin May be effectiveNSAIDs (ibuprofen, etc) Probably effectiveVitamin E, vitamin C, beta Not effectivecaroteneFolate Effective if obtained in dietCalcium EffectiveEstrogen Effective, but has other problems
  • Future techniques for colorectal cancer screening• Stool DNA testing• Capsule endoscopy (Givens capsule)• CT colography (virtual colonoscopy)
  • Fecal Testing for Gene Mutations
  • Fecal Testing for Gene Mutations• Pros • No sedation or preparation necessary • Home-based (sample mailed to physician) • No risk• Cons • Current tests not very good (~50% of cancers missed) • Cost • Frequency of exam unknown • Not therapeutic • Not covered by insurance
  • Videocapsule
  • VideocapsuleLymphoma
  • CT ColographyColon Polyp
  • CT ColographyColon Polyp
  • CT Colography Colon Cancer
  • CT Colography• Pros • No sedation necessary • 20 min procedure vs. 25 min for colonoscopy • Low risk • Extracolonic lesions may be detected• Cons • Preparation (residual fluid cannot be aspirated) • Air insufflation • Cost (? need for more frequent exams) • Radiation dose (similar to barium enema) • Not therapeutic • Not covered by insurance
  • Summary• Colorectal cancer is the third most common cancer and cause of cancer death in the U.S.• Chemopreventive agents have modest benefit in average risk individuals• Screening for colorectal cancer saves lives!• Patient and physician compliance with screening is poor