7. Colon cancer Flashcards
COLORECTAL CANCER ?
- 3rd most common cancer in Poland.
- 2nd cause of cancer death in men, 3rd in women.
FAP-Familial adenomatous polyposis :
- Autosomal dominant inherited disease due to mutation of the APC(adenomatous polyposis coli) gene.
- More than 100 colonic adenomas are diagnostic.
- The risk of colorectal cancer is 100% in patients with FAP. Surgery is the only mean of preventing colonic cancer.
Hereditary non-polyposis colorectal cancer (Lynch’s syndrome) ?
- Autosomal dominant condition caused by a mutation in one of the DNA mismatch repair genes MLH1, MSH2, MSH6, PMS and PMS2.
CANCEROUS COLORECTAL POLYP ?
○ Superficial carcinoma:
- no involvement of the muscularis mucosa
- non-invasive, non-metastatic
○ Malignant polyp:
- muscularis mucosa involved.
- invasive, can give metastasis.
TNM classifications ?
- Primary Tumor (T) .
- Regional Lymph Nodes (N) .
- Distant Metastases (M) .
DUKES’ CLASSIFICATION FOR
COLON CANCER ?
- A: confined to the bowel wall.
- B: through the bowel wall but not involving the free peritoneal serosal surface.
- C: lymph nodes involved.
- D: advanced local disease or metastases to the liver.
SYMPTOMS OF COLORECTAL CANCER ?
- Occult blood in stool.
- Abdominal pain.
- Change in bowel habits.
- Rectal bleeding.
- Weight loss.
- Anemia.
- Palpable mass.
- Abdominal distention.
- Lack of apetite.
- Bowel obstruction.
- Metastatic disease: jaundice, ascites, hepatomegaly; other symptoms and signs from rarer sites of metastasis
Typical locations of colon cancers ?
- Rectum 30%-50%.
- Sigmoid 15-20%.
- Descending c. 5%.
- Transverse c. 10%.
- Caecum and ascending colon 15%.
CARCINOMA OF THE LEFT SIDE OF THE COLON ?
- MOST TUMOURS OCCUR IN THIS LOCATION. THEY ARE USUALLY OF THE STENOSING VARIETY.
Signs and symptoms of CARCINOMA OF THE LEFT SIDE OF THE COLON ?
- Rectal bleeding.
- Alteration in bowel habit.
- Tenesmus.
- Obstruction.
- In addition to symptoms of intestinal obstruction, a sigmoid cancer may give rise to a feeling of the need for evacuation, which may result in tenesmus accompanied by the passage of mucus and blood..
CARCINOMA OF THE TRANSVERSE
COLON ?
- Anaemia and lassitude
CARCINOMA OF THE CAECUM
AND ASCENDING COLON ?
- Anaemia, severe and unyielding to treatment.
- The presence of a mass in the right iliac fossa.
- A carcinoma of the caecum can be the apex of an intussusception, presenting with the symptoms of intermittent obstruction.
LAB TEST ABNORMALITIES of clonic cancer?
- Microcytic hypochromic anemia.
- CEA elevated.
- Fecal occult blood test(FOBT) positive.
METHODS OF INVESTIGATION OF
COLON CANCER ?
- Endoscopy.
- Ultrasonography (liver metastases).
- Abdominal CT.
- Chest X-ray or chest CT.
- EUS, MRI (evaluation of local tumour invasion).
OPERATIONS in caecum or ascending colon cancer ?
- Carcinoma of the caecum or ascending colon is treated when resectable by right hemicolectomy. When the hepatic flexure is involved, the resection must be extended correspondingly.
OPERATIONS:
In the carcinoma of the transverse colon ?
- when there is no obstruction, excision of the transverse colon and the two flexures together with the transverse mesocolon and the greater omentum, followed by end-to-end anastomosis, can be used. An alternative is an extended right hemicolectomy.
OPERATIONS:
Carcinoma of the splenic flexure ?
Carcinoma of the splenic flexure- extended left hemicolectomy. Descending colon – left hemicolectomy.
OPERATIONS:
Carcinoma of the sigmoid colon ?
Sigmoidectomy.
OPERATIONS:
Carcinoma of the rectum ?
low anterior resection, abdominoperineal resection.
WHEN A GROWTH IS FOUND TO BE
INOPERABLE ? Upper part of the left colon ?
- Upper part of the left colon, a colostomy is performed.
WHEN A GROWTH IS FOUND TO BE
INOPERABLE ? Pelvic colon?
- Pelvic colon - a left iliac fossa colostomy is preferable.
WHEN A GROWTH IS FOUND TO BE
INOPERABLE ?
ascending colon ?
- Inoperable growth in the ascending colon - a bypass using an ileocolic anastomosis is the best procedure.
WHEN A GROWTH IS FOUND TO BE
INOPERABLE ? multiple tumours ?
- A total colectomy needs to be considered for multiple tumours.
- over 95% of colonic carcinomas can be resected.
HEPATIC METASTASES ?
- 30% 5-year survival following hepatectomy for colorectal cancer metastases.
- Irresectable symptomatic hepatic metastases may be suitable for other treatments including cytotoxic drugs or ablative treatments.
