CRC for 5th.

1. Colorectal cancer (CRC) Dr. Mohamed Shekhani. MBChB-CABM-FRCP.

9. Tumor supp genes APC FAP, AFAP p53 Sporadic colon cancer DCC Non-syndromic FCRC Oncogenes myc Sporadic CRC ras src erbB2 Mismatch repair genes MLH1 HNPCC MLH3 Sporadic CRC Base excision repair genes MYH FAP, AFAP—aut resisive Gene Function Affected Gene Clinical Manifestation

13. Factors Associated with the Development of CRC Protective Factors Risk Factors No family history of colorectal cancer or an inherited colorectal cancer syndrome Family history of colorectal cancer or an inherited colorectal cancer syndrome Birth in Asia or Africa Personal history of inflammatory bowel disease Diet high in fruits and vegetables * Birth in North America or Northern Europe Regular aerobic exercise Diet high in red meat, sucrose, fat Calcium and folate supplementation Physical inactivity Lack of dietary calcium and folate Obesity Smoking Excessive alcohol intake Cholecystectomy

20. Stratification of Colorectal Cancer Risk Lifetime Risk Risk Level High 100 % Presence of familial adenomatous polyposis 10% Presence of hereditary nonpolyposis colorectal cancer Moderate 20% Presence of chronic colitis due to ulcerative colitis or Crohn's colitis 10-20% Familial: First-degree relative with colorectal cancer Average (negative family history ) 5-6% >50 years of age

25. Screening for those with Family H/O CRC or Adenomatous Polyps FDR(s) with CRC <60 ys CS at 40 or 10 years <affected relative If N,repeat *3-5 FDR(s) with CRC >60 ys CS at 40 ys If N, * 10 years FDR(s) with AdP <60 ys CS at 40 or 10 years <affected relative If N,rep *5 FDR(s) with AdP >60 ys CS at 40 ys Ind; if N, as average risk 2nd- or 3rd DR with ca or polyps CS as ARP If N, as ARP Patient Category Screening Surveillance

38. Algorithm for screening for CRC