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Colorectal Cancer Screening and Prevention.

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Colorectal Cancer Screening and Prevention . RFUMS The Chicago Medical School 2005 David R. Rudy, MD, MPH Professor and Chairman, Family and Preventive Medicine Preventive Medicine MTD 601. Prevention.
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Colorectal Cancer Screening and Prevention RFUMS The Chicago Medical School 2005 David R. Rudy, MD, MPH Professor and Chairman, Family and Preventive Medicine Preventive Medicine MTD 601

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Prevention Primary avoidance : keeping an illness procedure from happening (smoking suspension averts (95% of) lung malignancy Secondary counteractive action : interference of an infection procedure in a reparable stage (Ca cervix, colon - place for screening) Tertiary anticipation : halting or impeding a symptomatic sickness (enhancing hazard status after MI)

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Terms of Epidemiology Incidence - new cases over unit of time/unit of populace Prevalence - number of cases at a point in time/unit of populace Sensitivity (of a test) - extent of cases analyzed by a test Specificity - extent of populace without the malady that will test negative

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Criteria for screenability 1. Condition has noteworthy impact on life 2. Critical treatment accessible 3. Asymptomatic time of diagnoseability 4. Treatment in asymptomatic stage yields result better than postponing until side effects show up 5. Trial of sensible cost-affectability and specificity suitable for populace hazard 6. Occurrence adequate to legitimize cost

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Terms Positive prescient quality - possibility of a positive test connoting infection Negative prescient worth - shot of a negative test outcome implying nonattendance of sickness None of the swearing off can be told without information of pervasiveness of the ailment

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Colon Cancer: Causation Combined ecological and hereditary: Environmental causes incorporate eating regimen low in fiber and gut bile salts, higher in fat. (Harrison's Principles of Medicine; eleventh Ed). Hereditary qualities to be tended to in 2. 95% emerge from adenomas; 70-90 % from adenomatous polyps (10-30 % from sessile adenomas).

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TYPE PREVALENCE % MALIGNANT Tubular adenoma 75% 5% Tubulovillous 15 % 22% Villous adenoma 10 % 40 % Weighted chance (100 %) 10.5% 15-30% of (US) pop. adeno-polyps/life; Lifetime colon Ca hazard 2.5-2.6% (sporadic).

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Hyperplastic polyps Comprise up to 1/3/of all polyps: have no threatening potential - perceived just hy histopathology

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CRC areas: About 1/3 of polyps emerge proximal to the splenic flexure (cephalad). (I,e,. 2/3 of polyps can be found by sigmoidoscopy About 1/2 of colorectal carcinomas emerge proximal to the splenic flexure. (1/2 tumors found by sigmoidoscopy

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Polyps to Carcinoma Dwell time normal 10 years, subsequently five year interim between most screen techniques is sheltered. Chances of polyp getting to be malignancy in the individual case might be derived to be around 1 in 10 inside a lifetime.

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Relative criticalness of Colorectal Carcinoma Tumor Incidence Cause particular Case mortality Mort Lung 172,570 163,510 95% M:F =55%:45% CRC 145,290 56,290 39% Breast 212,930 40,870 19% Prostate 232,090 30,350 13% Jemal A, Tiwari RC, Murry T, Ward E , Samuels A, TiwariRC, Ghafoor A, Feuer EJ, Thun M: Cancer Statistics, 2005. CA: Cancer J. for Clin 2005; 55(1): 10-30

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"Weight OF SUFFERING" 1 145,290 rate CRC/US est. for '05; 56,290 passings US mortality F~M Second leading reason for growth demise US, without sex refinement, - yet well beneath lung tumor. Case Mortality 38.7% ( Jemal An, et al: Cancer Statistics, 2005. CA: Cancer J. for Clin 2005; 55(1): 10-30

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Case Mortality CRC 56,290/year US mortality 2005 ÷ 145,290 frequency CRC/US = 38.7% rough case mortality

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Relative occurrences CRC among five ethnic gatherings (see Table III 1B) Ethnic gathering RR Indigenous 488 1.0 Asian/PacIsl 699 1.4 Hispanic/Latino 731 1.5 Whites 988 2.0 African 1103 2.26 Cancer Incidence and Mortality Rates by Race and Ethnicity in the US 1996-2000 (Cancer Fact and Figures 2004, American Cancer Society)

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Relative mortality CRC among five ethnic gatherings (see Table III 1B) Ethnic gathering RR Asian/PacIslanders 27 1.0 Hispanic/Latino 29 1.1 Indigenous 30 1.1 African 40 1.5 Whites 42 1.6 Cancer Incidence and Mortality Rates by Race and Ethnicity in the US 1996-2000 (Cancer Fact and Figures 2004, American Cancer Society)

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Burden of Suffering 2: by colon versus rectal (2002) Colon Ca rate: 105,500/US/yr Colon Ca mortality: 48,100/US/yr (2002) infers ~ 45% colon Ca case mortality Rectal Ca rate: 42,000/US/yr Rectal Ca mortality: 8,500/Us/yr (2002) infers ~ 21% rectal Ca case mortality (02) Cancer Statistics, 2003. CA - Cancer Journ Clin. 2003; 53(1): 5-26

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Implications for expanding future CRC expect exponentially expanding rate with age The later the age onset of CRC the lesser the forcefulness Thus, CRC with age demonstrates an expanding occurrence and diminishing case mortality But - auxiliary aversion (of movement of polyps) may kill that inclination

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(COLORECTAL CANCER; BURDEN OF SUFFERING) Incidence rate:/100,000 Pop./year, 15/100,000 in 40-50 y.o., >400/100,000 in > 80 y.o. [Frame, Paul S: J Fam Pract, 1986; 22(6): 511] Fourth tumor in frequency, behind prostate, bosom and lung (third in each sex). Third in growth passings every sex after lung, prostate (guys) and lung, bosom (females)

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Characteristics of Colon Ca Left > Rt sores in men (prior finding); Right > Lft in ladies (more terrible forecast). Patients > 70 more inclined to show in Stages An or B. More youthful patients have more forceful sickness for a given stage

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Characteristics of CRC, ethnicity(1) African-and Hispano-Americans more averse to display in stages An or B. Asians have presentation designs like non-Hispanic whites. Provocative gut illness is a danger, might be considered premalignant.

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Characteristics of CRC, ethnicity(2) Askenazi Jews have lifetime danger of CRC equivalent to Caucasians w/first degree relative with adenomatous polyp or CRC = three times the lifetime aggregate danger (2.5% - > 7.5%)

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Characteristics of Colon Ca,( 3) Presentation with hematochezia renders a superior forecast (just incredible infection) After presentation with some other manifestation 83% bite the dust of ailment (e.g. BM change, obstacle).

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GENETICS AND COLON CANCER (1): Lifetime danger of CRC = 2.5%; Tripled when have first degree relative w/adenomatous colon polyp(s) or colon malignancy - to 7.5 Increasing future anticipated that would increment combined rate Several particular qualities distinguished

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Five - 10% of colon Ca happens in clear innate examples. Adenomatous polyposis disorders (APS) represent around 9-10% of CRC: Hereditary "Non-polyposis" Colon Cancer (HNPCC, Lynch disorder) - represents around 6%. Portrayed by both pedunculated and sessile premalignant polyps,

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Adenomatous Polyposis Syndromes Familial Adenomatous Polyposis (FAP): 1-2 % of CRC 100s - > 1000 CR polyps starting ahead of schedule in life. All create CRC by age 40. Gardner's disorder: various polyps, danger of colon malignancy, in addition to osteomas, epidermoid growths and sesmoid tumors. Turcot's disorder (assoc.. CNS tumors).

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CLINICAL PRESENTATION, (BRIEFLY) Hematochezia (unmistakable from melena): If first manifestation, has a tendency to demonstrate the dropping colon - with better anticipation. Change in gut propensity: e.g. exchanging constipation and looseness of the bowels. Obstipation to clinical lower inside deterrent.

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COLORECTAL CANCER SURVIVAL (Dukes Stages, 5 y): Stage A: restricted to mucosa and submucosa 90% Stage B: reaches out into muscularis or serosa 60-75% Stage C: one positive hub - 69% six or more positive hubs, 27% Stage D: mets. to liver, bone, lung 5%

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. COLORECTAL CANCER SURVIVAL(descriptive): Overall 5 yr Survival About 55-75% (proportional of 39% case mortality = 61%) With confined infection 80-90% With local metastases 36% With inaccessible metastasis 29% With scattered disease 5%

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Screening Methods' prosperity, reenactment model Meth FOBT FS/OBT DCBE BE/FS Colnoscpy q# yr 1 5 10 5 10 DcrCases 2378 1975 3087 3394 2812 3875 3570 DcrDths 1278 976 1556 1629 1418 1843 1690 DcrMort 53.5% 40.1 % 65.1% 68.1% 59.3% 77.1 % 70.7% Decr = diminish [cases, passings (net after complexities); death rate as percent] * Based on desire of 4988 cases CRC/100,000 pop total from the ages of 50 through 85 yrs or demise; and desire of 2391 passings because of CRC in this populace, in total (Winawer et al, Gastroenterology, Sept, 1997) .

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CRC Screening Guidelines as per AGA: Average Risk - Option 1 Digital rectal examination/fecal mysterious blood (DRE/FOBT) begin @ 50 years each yr (AGA): predicts half (or less) decreased mortality

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CRC Screening Guidelines: Average Risk - alternative 2 Flexible sigmoidoscopy like clockwork (60 cm): Predicts just 40% diminishment of CRC mortality

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CRC Screening Guidelines: Average Risk choice 3. FOBT + Flexible Sigmoidoscopy q 5 yr predicts 65% diminishment CRC mortality

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CRC Screening Guidelines: Average Risk - choices (AGA) 4. Double Contrast BE each five yr.; Predicts 68% decrease in mortality from CRC

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CRC Screening Guidelines: Average Risk - choices (AGA) 5. DCBE each 10 yr. Predicts 59% decrease in mortality because of CRC

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CRC Screening Guidelines: Average Risk - choices (AGA) 6. FS + DCBE each 5