Colorectal Cancer

Question 1

State the type of cancer most prevalent.

Answer 1

Adenocarcinoma. 86% presentation (> 60 yrs old).

Question 2

State a predisposing factor to Colorectal Cancer.

Answer 2

Hereditary: Familial adenomatous polyposis coli (FAP). Lynch syndrome. Familial colorectal cancer syndrome.
Inflammatory bowel disease: Ulcerative colitis, Crohn’s disease.
Environmental factors: high alcohol, red meat, low fibre increased risk.
Genetics: mutations in APC gene, hMSH2, hMLH1.

Question 3

State a type of Colorectal Cancer.

Answer 3

Lynch syndrome (hereditary non-polyposis colorectal cancer). Familial adenomatous polyposis. Peutz-Jeghers Syndrome.

Question 4

Define Lynch Syndrome.

Answer 4

Autosomal dominant mutation of mismatch repair genes e.g. MLH1, MSH2, MSH6. Increased risk of other ‘lynch cancer’ - endometrium, ovary, urinary tract, stomach, bowel.

Question 5

What form of Chemoprevention is used in Lynch Syndrome?

Answer 5

Aspirin.

Question 6

Define Familial Adenomatous Polyposis.

Answer 6

Mutation of APC tumour suppressor gene. Colorectal polyps present. Malignant transformation (age of 40).

Question 7

State the surgery used for Familial Adenomatous Polyposis.

Answer 7

Prophylactic colectomy (removal of part/entire colon to prevent cancers). Sigmoidoscopy (from 12yrs).

Question 8

Define Peutz-Jeghers Syndrome.

Answer 8

Hamartomatous polyps (focal malformation in tissue). Due to germline mutations in STK11 (tumour suppressor gene).

Question 9

State a cause for Peutz-Jeghers Syndrome.

Answer 9

Arise from colonic epithelial tissue - adenomatous polyp formation, adenocarcinoma.

Question 10

Define an adenocarcinoma.

Answer 10

Malignant tumour formed from glandular tissues in epithelial tissue.

Question 11

State a test for colorectal cancer.

Answer 11

FBC - anaemia. Faecal occult blood. Colonoscopy (camera used to check inside bowels). CT scan of chest, abdomen and pain. MRI to monitor disease and effectiveness of treatment.

Question 12

State a presentation of colorectal cancer.

Answer 12

Change in bowel habit (constipation, diarrhoea, increased bowel frequency, straining at stool). Rectal bleeding. Abdominal mass. Weight loss. Invasion of other organs (fistula - abnormal opening connecting two or more organs inside/outside body).

Question 13

Define an adenoma.

Answer 13

Benign tumour of glandular tissue (e.g. mucosa of stomach, SI or colon)

Question 14

Define a carcinoma.

Answer 14

Tumour making up cells of skin/tissue lining organs e.g. liver/kidneys.

Question 15

State the presentation of right-sided Colorectal Cancer.

Answer 15

Non-obstructive. Occult bleeding. Iron deficiency.

Question 16

State the presentation of left-sided Colorectal Cancer.

Answer 16

Ring shaped. Obstructive. Constipation and pain. Change in bowel habits. Colicky abdominal pain. Blood coating of stool. Straining at stool. Mucus PR.

Question 17

State a modifiable risk factor of Colorectal Cancer.

Answer 17

Smoking. Red meat. Low fiber. Obesity.

Question 18

State the staging system of Colorectal Cancer.

Answer 18

Tumour. Node. Metastasis.

Question 19

State the surgery used in Colorectal Cancer.

Answer 19

Right hemicolectomy, left hemicolectomy and sigmoid colectomy - procedure used to remove/all of colon.
Permanent Colostomy - operation to divert one end of the colon (part of bowel) through opening in tummy. Opening called stoma/pouch collects stool.

Question 20

State a treatment for Colorectal Cancer.

Answer 20

Surgery. Radiotherapy - used in patients with rectal tumours at high risk of local recurrence. Chemotherapy - FOLFOX regimen (fluorouracil, folinic acid and oxaliplatin), Biological therapy - bevacizumab (anti vascular growth factor), cetuximab, paritumumab (anti-epidermal growth factor receptor).

Question 21

State the prognosis of Colorectal Cancer.

Answer 21

Stage 1 disease - 5yr survival (75%).

Stage 4 disease - 5yr survival (5%).

Question 22

State the chemotherapy used for Colorectal Cancer.

Answer 22

Chemotherapy - FOLFOX regimen (fluorouracil, folinic acid and oxaliplatin).

Question 23

State the Biological Therapy used for Colorectal Cancer.

Answer 23

Biological therapy - bevacizumab (anti vascular growth factor), cetuximab, paritumumab (anti-epidermal growth factor receptor).