Git CRC 4th 2012 abstract.
24
LOGO Colorectal cancer: Dr. Mohamed Shekhani 2012
description
COLO-RECTAL CANCER
Transcript of Git CRC 4th 2012 abstract.
LOGO
Colorectal cancer:
Dr. Mohamed Shekhani
2012
Contents
CRC clinical presentations2
Familial CRC4
Sporadic CRC33
CRC location distribution.31
Contents
CRC Precursors2
CRC screening4
Hereditary CRC syndromes33
CRC Epidemiology31
CRC: Epidemiology/risk factors
Sporadic average riskMost common GIT cancer
3rd most common cancer
2nd most common cancer
death
2% die from this cancer.
Men>women
Blacks>white
Increase sharply after 50
CRC
Epidemiology
Hereditary CRC
syndromes:Higher than average
CRC risk &include:
FAP
AFAP
HNPCC
IBD
Familial CRC.
Stratification of Colorectal Cancer Risk
Most
minority
Text
Average risk-ve family
history
LTR 5-6%>50 years.
High risk
•FAP 100%•HNPCC 10%•IBD 10-20%
•Familial FDR 10%Occur earlier <50
years.
CRC Risk
ALL
Risk/protective factors for CRC
CRC
Risk factors
Hereditary CRC
IBD
WESTERN
No family H/O CRC
Asia/Africa
High veg;fruits/
calcium/folate
protective factors
Physical inactivity
High red meat,
sucrose,fat
Low calcium/folate.
Obesity,smoking,
Alcohol,
cholecystectomy
Physical activity
Adenoma-carcinoma sequence develop over
10 years: rationale for screening
CRC: Adenoma-carcinoma sequence
Rationale for screening by colonoscopy
CRC
LAP with dysplasia
Large adenomatous polyps
Small adenomatous polyps
Normal
Screening for early detection
30-50% of adults develop adenomatous polyps during their lifetime, but only 1 / 20 will progress to cancer. 15-25% >50 ys have adenomatous polyps, males>females.
Hereditary CRC Syndromes: FAP
Mutation in APC genes
100% will develop 100s of
adenomatous colonic polyps & cancer
By 40 years age.
GIT Extra colonic tumors:
2nd most common after colonic;
adenoma/adenocan of ampulla of vater,
Fundal gland polyps.
FAP
Hereditary CRC Syndromes: FAP
Need screening colonoscopy earlier than
The usual age of 50 years
Extra GIT Features:
Bone/soft tissue tumors
Retinal pigment epith hypertrophy
Treatment:
Total colectomy with ileostomy to
prevent cancer.
FAP
Hereditary CRC Syndromes: AFAP
Mutations at the terminal end of
the APC gene
20 or more adenoma
SAME RISK OF CRC.
AFAP
Hereditary CRC Syndromes: HNPCC
Mutations at DNA MMR gene
Polyps larger
more in proximal colon
Progress more rapidly to CRC.
8O% develop cancer >50
Vs 5% > 50 in average risk persons.
Extra-colonic tumors:FRS,Kid,pancbil,SI
HNPCC
Hereditary CRC Syndromes: familial
Do not meet criteria for FAP or HNPCC
1ST degree or 2nd degree relative with
CRC before or after 50
Risk increase with increasing numbers of
Affected relatives.
Familal CRC
Hereditary CRC Syndromes: others
Familial juvenile polyposis
the Peutz-Jeghers syndrome
(hamartomatous polyps)
Both at increased risk for developing CRC.
others
IBD CRC risk
Duration > 8 years of active colitis
Early age of onset
Extent
Presence of PSC.
IBD CRC Risk
Algorithm for screening for CRC
Management
Surgery is the only hope for cure.
Carcinomas within 2 cm of the anal verge may require abdomin-
operineal resection & colostomy.
Postoperative colonoscopy after 6–12 months &periodically
thereafter for local recurrence or new ‘metachronous’ lesions,
occuring in 6% of cases.
Adjuvant radio-chemotherapy for rectal cancer.
Paliative chemo-radiotherapy or stenting for inoperable cases.
LOGO
2012
