colorectal cancer

Question 1

what is the second leading cause of cancer death in western world?

Answer 1

colorectal

Question 2

how many deaths does colorectal cancer cause?

Answer 2

17,000 deaths/year

Question 3

what percentage of colorectal cancers are adenocarcinomas?

Answer 3

95%

Question 4

risk factors for colorectal cancer

Answer 4

Age 
Male gender
Previous adenoma/CRC
Environmental influences:
Diet (fibre, fruit & veg,
 calcium, red meat, alcohol,)
Obesity
Lack of exercise
Smoking
Diabetes Mellitus

Question 5

what do the majority of colorectal cancers arise from?

Answer 5

pre-existing polyps

Question 6

presentation of colorectal cancer

Answer 6

Rectal bleeding (especially if mixed in with stool)
Altered bowel opening to loose stools >4 weeks
Iron Deficiency Anaemia men of any age and non-menstruating women (more likely to have right sided colonic malignancy)
Palpable rectal or right lower abdominal mass
Acute colonic obstruction if stenosing tumour
Systemic symptoms of malignancy: Weight loss, Anorexia

Question 7

investigations for colorectal cancer

Answer 7

colonoscopy

```
radiological imaging
Barium enema
CT colonography
3D virtual colonoscopy
CT abdo/pelvis
~~~

Question 8

treatment for colorectal cancer

Answer 8

surgery 80%

chemotherapy
radiotherapy

Question 9

prevention of colorectal caner

Answer 9

SCREENING
Average Risk Population
High Risk Groups

Question 10

what is the aim of colorectal cancer screening?

Answer 10

detect pre-malignant adenomas/ early cancers in the general population

Question 11

who are high risk groups for colorectal cancer screening

Answer 11

Heritable conditions
FAP (familial adenomatous polyposis)
HNPCC (hereditary non-polyposis colorectal cancer)
Inflammatory bowel disease
Familial risk
Previous adenomas/Colorectal cancer

Question 12

what is Familial adenomatous polyposis

Answer 12

an autosomal dominant inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine

Question 13

extracolonic manifestations of FAP

Answer 13

benign gastric fundic cystic hyperplastic

duodenal adenomas in 90% with periampullary cancer ~5% (surveillence endoscopy)

Question 14

what is Hereditary nonpolyposis colorectal cancer

Answer 14

most common form of hereditary colorectal cancer

autosomal dominant condition. mutation in DNA mismatch repair genes