COLO RECTAL CARCINOMA

COLO RECTAL CARCINOMA

• Colo rectal carcinoma is the carcinoma affecting caecum, colon & rectum.
• It is the most common internal carcinoma in western world.
• 1/3^rd of tumour are in rectum & 2/3^rd in colon.

Etiology-

• Environmental factors
• Diet rich in fat, meat & low in fibre.
• Adenomatous polyps
• Genetic factors
• Inflammatory bowel disease
• Surgical procedures- Ureterosigmoidostomy
• Choleccystectomy

Pathology

• Colo rectal carcinoma occurs- rectum (38%), sigmoid (21%), descending colon (4%), cancer of caecum (12%), ascending colon (5%)
• Staging-

• The most important prognostic factor of colorectal carcinoma is the ‘stage of disease’.
• The two most important prognostic factors-
• Depth of invasion
• Lymph node status

Clinical features-

Right colon tumors

• Growth: fungative, ulcerative, polypoid or cauliflower like
• Infiltration absent
• Iron deficiency anemia due to chronic blood loss
• Palpable mass in the RIF, which is not moving with respiration
• Spurious (early morning) diarrhea

Left sided colon tumours

• Growth: obstructive, annular lesions producing napkin ring constriction
• Infiltration present
• Rectal bleeding, Colicky pain
• Altered bowel habits (alternating diarrhea and constipation)
• Abdominal distension due to subacute/chronic obstruction
• Tenesmus

Investigations–

• Barium enema: apple core lesion in left sided carcinoma
• Colonoscopy and biopsy: is the investigation of choice
• CEA: normal level <2.5ng/ml; >5ng/m1 significant
• Low sensitivity(also ↑ in pancreatitis, hepatitis, obstructive jaundice, BPH)
• Pre-op levels >7.5ng/ml indicates poor prognosis
• Increase in CEA during follow up
• Slow rise – loco regional disease
• Rapid rise – metastasis

Treatment-

• Bowel preparation is not safe for right sided colonic surgery. The method used is dietary restriction to fluids only for 48 hrs before surgery
• Carcinoma of the caecum or ascending colon: right hemicolectomy
• Carcinomas of the transverse colon and splenic flexure: extended right hemicolectomy
• Carcinomas of descending and sigmoid colon: left hemicolectomy
• Right sided tumors presenting as obstruction: right hemicolectomy
• Left sided tumors presenting as obstruction
• Hartmann’s procedure or resection and anastomosis
• If facilities available an expanding metal stent followed by resection and anastamosis
• The criteria for resection is < 3 lesions in one lobe of the liver
• Chemotherapy
• 5-FU + (folinic acid)Leucovorin + Irinotecan (topoisomerase-1 inhibitor) improves survival in patients with metastatic disease(FOLFIRI regimen)
• 5-FU + (folinic acid)Leucovorin + Oxiplatin(FOLFOX regimen) is equally effective

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