COLORECTAL CANCER
DR. KENNETH LAM
MAY 8, 2000
Colorectal Cancer:
Colorectal cancer is not as common as prostate cancer or breast cancer,
however it is not a rare cancer.
The incidence of colorectal cancer in this country is going down
12% estimated incidences
10% estimated deaths
3rd most common cancer, and cause of cancer death in both men and
women
The older you are the higher risk you have
Most common age group for Colorectal cancer is 55-79
Certain patients are more at risk if the y have a strong family history of
cancer
Death rates have gone down do to the increase of early diagnosis
The cure rate is rising to approximately 60%
Risk of colorectal cancer is less in the less developed countries due to the
lack of rich foods. Richer countries tend to eat richer foods.
Anti-oxidants will lower risk of some cancers
Most common site is the distal end of intestine
The liver is the first site for metastasis for colorectal cancer. Once the
cancer has spread to the liver, then the cancer turns into an incurable cancer.
Every person with cancer is different; treatment is not exactly the same for
each patient.
Each cancer patient has different beliefs. Each patient experiences anxiety,
depression, and fear.
Epidemiology:
Lack of fiber in diet
Saturated fat and cholesterol
Lack of selenium, calcium, and/or aspirin
Benign polyps
Genetic/ family history of oncogenes
Screening:
Hemoccult stool tests for blood (not accurate)
Digital rectal exam (not accurate)
Barium/x-ray studies
Flexible fibro-optic sigmoidoscopy
Colonoscopy
CT/ MRI
Tumor markers
Patient Management:
Biopsy - if cancer looks aggressive (higher rate), high chance of cancer
spreading
Grading
Therapeutic decision
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Biopsy ---------Cancer Diagnosis
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Grading Staging
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Metastatic/ Localized
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Therapeutic decision
Barium Enema:
Inserted into rectum
Normal colon: lumen is narrow
Colon cancer: lumen is wide
Cat Scan (CT):
Detail about inside of body by cross-section
CT on upper abdomen to see if any protrusions on liver. Protrusions indicate
that the cancer has spread to the liver.
Tumor / Staging
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Metestatic
Disease
Localized disease = limited stage
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Extent
Resectable
Non-resectable
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Chemotherapy
Operable/Inoperable patient
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Radiation
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Surgery
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Immunotherapy
Surgery
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Hormonotherapy
Radiation
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Palliative
Care
Chemotherapy
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Homonotherapy
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Immunotherapy
Staging:
A - confined to mucora and submucora (80%)
B - invasion through the musculature with no lymph node involvement (50%)
C - metastasis to regional lymph nodes
Dukes Staging System for Rectal Cancer:
Stage Description
A confined to mucosa and submucosa (80%)
B invasion through the musculature with no lymph node involvement
C metastases to regional lymph nodes
C1 lymph nodes not involved up to the point of vascular ligation (40%)
C2 nodes involved up to the lever of vascular ligation (12%)
Treatment:
Surgery
Colectomy
Low interior resection and anastamosis
Abdominal-perennial resection
Radiation therapy
Usually for 6 weeks, and 5 days per week
Side effects: diarrhea and fatigue
Chemotherapy
5FU
Lavamisole
Leucourin
* Surgery is not 100% effective that are why treatment is continued with
radiation therapy and chemotherapy, however the primary treatment is surgery
* Tumor resides on the inside of colon wall
* A combination of both Chemotherapy and Radiation therapy gives the highest
chance cure rate
* Receiving no treatment gives you the lowest cure rate
CEA (tumor marker for colorectal cancer):
Carcino embryonic antigen
Elevated in colorectal cancer
Normal = 2.5 Ng/ml
May be elevated also in liver disease, cigarette smoking
CEA can also be used to detect other types of cancer
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