Quick Review: Cancer Of The Large Intestine
B Phillips, C Perry
Keywords
cancer, colon, gastroenterology, medicine, rectal cancer
Citation
B Phillips, C Perry. Quick Review: Cancer Of The Large Intestine. The Internet Journal of Gastroenterology. 2000 Volume 1 Number 2.
Abstract
150,000 new cases of Colorectal CA
are diagnosed each year in the United States and 60,000 people die of this
disease annually. The actual incidence increases with age: at dge 50, 0.39
per 1000 persons/yr; at age 80, 4.5 per 1000 persons/yr. Carcinoma of the
colon (particularly the right side) is more common in women while carcinoma
of the rectum is more common in men.
Right Colon
-
Unexplained Weakness or Anemia
-
(+) Occult Blood
-
Dyspeptic Symptoms
Left Colon
-
Change in Bowel Habits
-
(+) Gross Blood
-
Obstructive Symptoms
Rectum
-
Rectal Bleeding
-
Intrarectal Tumor
-
Sigmoidoscopic Findings
Incidence
150,000 New Cases of Colorectal CA are Diagnosed Each Year in the USA
60,000 People Die of this Disease Each Year
-
Age 50, 0.39 per 1000 persons/yr
-
Age 80, 4.5 per 1000 persons/yr
-
Carcinoma of the Colon (particularly the Right Side) is More Common in Women
-
Carcinoma of the Rectum is More Common in Men
Genetic Predisposition Has Been Well Documented
-
Familial Adenomatous Polyposis (Chromosome 5)
-
Cancer Family Syndrome (Lynch II): Early Onset (age 20 -30) Proximal Dominance Endometrial Carcinoma
-
Hereditary Site-Specific Colon Cancer (Lynch I)
-
Ulcerative Colitis
-
Crohn's Colitis
-
Schistosomal Colitis
-
Exposure to Radiation
Mechanisms of Spread
Direct Extension [Carcinoma grows Circumferentially]
Hematogenous Metastasis [Portal Venous Blood to the Liver]
Regional Node Metastasis [Most Common Form]
Transperitoneal Metastasis [“Seeding” - through the Serosa]
Intraluminal Metastasis [Rare !]
Duke's Classification
-
Limited to the Bowel Wall
-
Extension through the Bowel Wall with Negative Nodes
-
Regional Node Metastasis
Duke's Modification
C 1 - Regional Node Metastasis
C 2 - Node Involvement at the Point of Vessel Ligation
Aster Coller Modification
A - Limited to Mucosa
B 1 - Extension into the Muscularis Propria
B 2 - Extension though the Muscularis Propria
C 1 - Limited to the Bowel Wall, with Positive Nodes
C 2 - Involvement of the Entire Bowel Wall, with Positive Nodes
“D” - Distant Metastases or Unresectable Lesions
(Not Formally Included in Any Classification)
Average 5-yr. Survival Rates using Duke's
-
Stage A - 80 %
-
Stage B - 60 %
-
Stage C - 30 %
-
Stage D - 5 %
Some Points
-
Approximately 10 % of lesions are Not Resectable at the time of operation
-
An Additional 20 % of patients have liver or other distant metastases
-
Operation, for Cure, can only be performed on about 70 % of all patients
-
Operative Mortality Rate : 2 - 6 %
-
Survival Rate of Patients undergoing Curative Resection is 55 %
-
Overall Survival Rate (all stages) is 35 %
TNM Classification of Colorectal Cancer
Primary Tumor (T)
Tx: Primary Tumor Cannot Be Assessed
To: No Evidence of Primary Tumor
Tis: Carcinoma in situ
T1 : Tumor invades the Submucosa
T2 : Tumor invades the Muscularis Propria
T3 : Tumor invades into the Subserosa
T4 : Tumor perforates the Visceral Peritoneum (or directly invades other organs)
Regional Lymph Nodes (N)
Nx : Regional lymph nodes can not be assessed
No : No regional lymph node metastasis
N1 : Metastasis in one to three pericolic or perirectal lymph nodes
N2 : Metastasis in four or more pericolic or perirectal lymph nodes
N3 : Metastasis in any lymph node along the course of a named vascular trunk
Distant Metastasis (M)
Mx : Presence of metastasis cannot be assessed
Mo : No Distant Metastasis
M1 : Distant Metastasis
