L15: Cancer Colon Flashcards
Arterial Supply of The Colon
Branches of SMA to The Colon
a) Ilio-colic
b) Right colic
c) Middle colic:
Level of SMA
L1
Branches of IMA to The Colon
a) Upper and lower left colic
b) Sigmoid arteries
c) Superior rectal artery
Level of IMA
L3
Arterial Supply of The Rectum
SRA
(hemorrhoidal) artery - branch of IMA
MRA
branch of internal iliac artery
IRA
branch of internal iliac artery
What are the “watershed” areas of the colon?
Venous Drainage of Colon
Venous Drainage of Rectum
Lymphatic Drainage of Colon
Lymphatic Drainage of Rectum
Histology of Colon
Mucosa of Colon
Columnar epithelium
Musclosa of Colon
1) Inner circular
2) Outer longitudinal (condensed into 3 bands)
Serosa of Colon
1) (Visceral peritoneum)
2) Peritoneal covering incomplete (except transverse & sigmoid)
Which portions of the colon are retroperitoneal?
Why Surgery of The Colon is More Hazardous Than SI?
Why is Colonic Anastomosis Leakage More Common Than SI?
Preoperative Colon Preparation for Elective Surgery to Decrease Risk of Anastomosic Leak
Incidence of Cancer Colon
3rd most common cancer in both male & female
Age of Cancer Colon
- 90% of cases above 50 years
- uncommon below 40 y unless hereditary
Sex in Cancer Colon
Equal “Maybe Males”
Sites of Cancer Colon
1/3 are in the rectum and 2/3 in the colon.
Synchronous & Metasynchronous Cancer Colon
5%
Why is Cancer Colon more common in Rectum & Sigmoid?
1) Contents are solid, stagnant.
2) It is often seat of precancerous lesions as polyps and UC
Categories of Cancer Colon
- Sporadic colon cancer
- Familial colon cancer
Percentage of Sporadic Cancer Colon
75%
Risk Factors For Sporadic Cancer Colon
1) Diet
2) Chronic irritation
3) Precancerous lesion
Predisposing factors for Sporadic Cancer Colon
1) Diet
2) Chronic irritation
3) Precancerous lesion
Diet & Sporadic Cancer Colon
Chronic Irritation & Sporadic Cancer Colon
Precancerous Lesions & Sporadic Cancer Colon
Percentage of Familial Cancer Colon
25%
Risk Factors for Familial Cancer Colon
Nature of Familial Adenomatous Polyposis (FAP)
Autosomal dominant
Gene Defect in Familial Adenomatous Polyposis (FAP)
Defect in (APC) gene on chromosome 5
Colon Cancer Risk in Familial Adenomatous Polyposis (FAP)
COLON CANCER: 100%
Age of polyps & cancer in Familial Adenomatous Polyposis (FAP)
- Polyps appear by the age of 15 years
- Cancer occurs berore age of 40 years
Types of Familial Adenomatous Polyposis (FAP)
Attenuated Type of Familial Adenomatous Polyposis (FAP)
(number of polyps is less than 100)
Classic Type of Familial Adenomatous Polyposis (FAP)
(number of polyps is more than 100)
Nature of Heridetery non-polyposis Colon Cancer (HNPCC)
Autosomal dominant
Gene defect in Heridetery non-polyposis Colon Cancer (HNPCC)
Defect in mismatch repair MMR gene (chromosome 2)
Risk of Cancer in Heridetery non-polyposis Colon Cancer (HNPCC)
COLORECTAL CANCER: 80 %
Age of cancer in Heridetery non-polyposis Colon Cancer (HNPCC)
Occurs before 45 years
Types of Heridetery non-polyposis Colon Cancer (HNPCC)
Lynch I
isolated CRC
Lynch II
CRC associated with:
* Endometrial
* Ovarian
* Prostatic
* Gastric
* Renal
* Ureteric tumors.
Amesterdam Criteria for HNPCC
Presentation of FAP
Colonic Manifestations of FAP
Extra-Colonic Manifestations of FAP
Investigations in FAP
Screening in FAP
TTT of FAP
Asymptomatic Cancer Colon
Emergency symptoms of Cancer Colon
Shape of Cancer Right Colon
Cauliflower
CP of Cancer Right Colon
- AAA (Commonest presentation)
- Pain
- Mass in RIF
- Acute presentations of cancer caecum
Commonest Presentation of Cancer Right Colon
AAA (Commonest presentation)
a. Anorexia (Decrease appetite)
b. Asthenia (Unintended weight loss)
c. Anemia
Pain in Cancer Right Colon
- Type: Colicky pain
- Cause: Hyper-peristalsis to get rid of tumor
Mass in RIF in Cancer Right Colon
tumor itself, late symptom
Acute Presentation of Cancer Caecum
a. Acute intestinal obstruction. (Rare)
b. Acute appendicitis: due to obstruction
to its lumen by carcinoma
c. Perforation of the caecum & peritonitis.
Shape of Cancer left colon
annular
CP of Cancer left colon
- Change in the bowel habits (Commonest presentation)
- Bleeding per rectum
- mass in LIF
- Intestinal obstruction (common)
Change in the bowel habits in Cancer left colon
a. Progressive constipation
b. Attacks of constipation are followed by false diarrhea
c. Change in the shape of stool (narrower than normal)
Mass in LIF in Cancer left colon
fecal impaction above tumor
CP of Rectal cancer
Bleeding Per Rectum in Rectal cancer
is the early & common symptom
Tenesmus in Rectal cancer
sense of incomplete defecation
PR Examination in Rectal cancer
a. Rectal tumors felt in 90% of cases
b. Mucus & blood per rectum.
general Examination in Colon Cancer
Local Examination in Colon Cancer
Abdominal Mass in Colon Cancer
INVx in Colon Cancer
- Labs
- Colonoscopy & biopsy: gold standard
- Rads
- metastatic Workup
Labs in Colon Cancer
Occult Blood in Colon Cancer
always positive.
CBC in Colon Cancer
Anemia
Tumor Markers in Colon Cancer
- CEA (> 2.5 ng/ml): prognostic rather than diagnostic
- CA 19-9 — more specific
Is CEA Specific to Colon Cancer?
What is The gold Standard in INVx of Colon Cancer?
Colonscopy + Bx
Role of Colonoscopy & Bx in Colon Cancer
NE of Colon Cancer
ME of Colon Cancer
Rads in Colon Cancer
- Barium Enema
- Double Contrast Barium Enema (DCBE)
- CT Virtual Colonoscopy
Barium Enema in Colon Cancer
a. Filling defects in polypoidal lesions
b. or (Apple core appearance): in annular lesions
(irregular stricture with mucosal destruction and shouldering)
Double Contrast Barium Enema in Colon Cancer
CT Virtual Colonoscopy in Colon Cancer
Advantages of Colonoscopy in Colon Cancer
- Evaluation of entire colon
- Biopsy
- Treatment of poiyps
Disadvantages of Colonoscopy in Colon Cancer
- Perforation, bleeding
- require bowe!: preparation
Advantages of Sigmoidscopy in Colon Cancer
- Fairly quick and safe
- Does not require full bowel preparation
Disadvantages of Sigmoidscopy in Colon Cancer
- Perforation
- Missed lesion (40-50% of CRC and polyps)
Advantages of CT Colonography Colon Cancer
- Non-invasive
- Detection of extracolon lesions/disease
- Can see proximal to obstructing lesion
Disadvantages of CT Colonography Colon Cancer
- No biopsy
- Bowel preparation
Metastatic Work up in Colon Cancer
- CT abdomen with contrast
- Endoluminal US
- (PET) scan
CT Abdomen With Contarst in Colon Cancer
EUS in Colon Cancer
Duke’s Staging in Colon Cancer
Duke’s Modified Staging in Colon Cancer
TNM Staging in Colon Cancer
TNM Staging in Colon Cancer
- T
TNM Staging in Colon Cancer
- N
TNM Staging in Colon Cancer
- M
What Does Grading of Colon Cancer depend on?
Grades of Colon Cancer
Spread of Colon Cancer
Direct Spread of Colon Cancer
Lymphatic Spread of Colon Cancer
Blood (Distant) Spread of Colon Cancer
Most Common Method of Spread of Colon Cancer?
Intra-Luminal Spread of Colon Cancer
Trans-Peritoneal Spread of Colon Cancer
Prevention of Colon Cancer
1ry Prevention of Colon Cancer
2ry Prevention of Colon Cancer
Screening of Colon Cancer
Methods of Screening of Colon Cancer
Average Risk Screening for Colon Cancer
Mild Risk Screening for Colon Cancer
High Risk Screening for Colon Cancer
Who are at mild Risk of Colon Cancer?
Who are at High Risk for Colon Cancer?
Principles of Colonic Resection
TTT options in Colon Cancer
TTT of Localized uncomplicated Colon Cancer
Neo-Adjuvant Therapy in Colon Cancer
Adjuvant Therapy in Colon Cancer
Pre-operative Colonic Prerparation in Colon Cancer
Operation for Tumor in Hepatic Flexure
Types of Operation in Colon Cancer
Operation for Tumor in Caecum - ascending
colon
Operation for Tumor in Transverse Colon
Operation for Tumor in descending Colon
Operation for Tumor in sigmoid Colon
Operation for Tumor in Recto-Sigmoid Junction
Operation for Tumor in low rectum
Operation for Synchronous Colon Cancer
managment of Metastatic Colon Cancer
The most important prognostic factor in Colon Cancer
5 year survival differs according to the stage
- Explain
Done
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