Diagnosis

Barium studies

• demonstrate the primary lesion and reveal a synchronous cancer elsewhere in the colon  

Annular constricting or napkin-ring carcinoma of colon

Annular constricting or napkin-ring carcinoma of colon

• Colonoscopy– most accurate and complete examination of

the large bowel. • The purpose of a complete colon and

rectal evaluation for patients with large-bowel cancer is to rule out synchronous carcinomas and polyps.

• Serum level of CEA – important in the evaluation of patients with

colorectal cancer.

• Chest x-ray - pulmonary metastasis. • CT of the abdomen - extent of invasion

of the primary tumor and to search for intraabdominal metastatic disease.

Staging

• depth of tumor, penetration into the bowel wall

• presence of both regional lymph node involvement

• distant metastases

Staging of colorectal cancer

TABLE 3 - 43. STAGING OF COLORECTAL CANCER–AMERICAN JOINT COMMITTEE ON CANCER USING THE TNM CLASSIFICATION

Stage 0

Carcinoma in situ Tis N0 M0

Stage I

Tumor invades submucosa T1 N0 M0

Tumor invades muscularis propria T2 N0 M0

Stage II

Tumor invades through muscularis propria into subserosa or into nonperitonealized pericolic or perirectal tissues T3 N0 M0

Tumor perforates the visceral peritoneum or directly invades other organs or structures T4 N0 M0

Stage III

Any degree of bowel wall perforation with regional lymph node metastasis

N1 1 to 3 pericolic or perirectal lymph nodes involved

N2 4 or more pericolic or perirectal lymph nodes involved

N3 Metastasis in any lymph node along a named vascular trunk

Any T N1, M0

Any T N2, N3 M0

Stage IV

Any invasion of bowel wall with or without lymph node metastasis but with evidence of distant metastasis

Any T Any N M1

Dukes' B (corresponds to Stage II) is a composite of better (T3, N0, M0) and worse (T4, N0, M0) prognostic groups as is Dukes' C (corresponds to Stage III) (any T, N1, M0) and (any T, N2, N3, M0)

Treatment

Optimum Treatment Strategy

• Surgery is the only hope for CURE• Adjuvant chemotherapy for Colon CA

– > Stage III disease– High risk Stage II disease

• Obstruction / Perforation• High grade histology

• Adjuvant chemo-radiotherapy for Rectal CA– > Stage II disease– Either pre-operative or post-operative

• Total resection of tumor - optimal treatment when a malignant lesion is detected in the large bowel.. • The detection of metastases should not preclude surgery in patients with tumor-related symptoms such as

gastrointestinal bleeding or obstruction, but it often prompts the use of a less radical operative procedure. • Laparotomy- the entire peritoneal cavity should be examined, with thorough inspection of the liver, pelvis,

and hemidiaphragm and careful palpation of the full length of the large bowel.

Radiation therapy

• reduces the 20–25% probability of regional recurrences following complete surgical resection of stage II or III tumors, especially if they have penetrated through the serosa.

• either pre- or postoperatively, reduces the likelihood of pelvic recurrences but does not appear to prolong survival.

Chemotherapy

• 5-FU – backbone of treatment• Concomitant administration of folinic

acid (leucovorin) improves the efficacy of 5-FU in patients with advanced colorectal cancer, presumably by enhancing the binding of 5-FU to its target enzyme, thymidylate synthase.

• Irinotecan - prolongs survival when compared to supportive care in patients whose disease has progressed on 5-FU.

• FOLFIRI regimen Irinotecan -180 mg/m2 as a 90-min infusion day 1 LV - 400 mg/m2 as a 2-h infusion during irinotecan 5-FU bolus - 400 mg/m2 and 46-h continuous infusion of

2.4–3 g/m2 every 2 weeks.

• FOLFOX regimen – 2-h infusion of LV (400 mg/m2 per day) – 5-FU bolus -(400 mg/m2 per day) and 22-h infusion (1200

mg/m2) every 2 weeks, – Oxaliplatin, 85 mg/m2 as a 2-h infusion on day 1.

• FOLFIRI and FOLFOX are equal in efficacy.