Colorectal Cancer

Question 1

What are polyps?

Answer 1

Protrusions of the epithelial surface

Question 2

How can polyps present?

Answer 2

Flat, pedunculate, serrated

Question 3

What are adenomas?

Answer 3

Benign glandular tissue tumour
Can be derived from polyps
Have potential to become adenocarcinomas

Question 4

Cause of FAP

Answer 4

Auto dominant mutation of tumour suppressor gene APC

Question 5

Cause of HNPCC

Answer 5

Defect in DNA mismatch repair gene

Question 6

Onset and area affected - FAP

Answer 6

Early-onset, all of colon

Question 7

Onset and area affects - HNPCC

Answer 7

Late-onset, right-sided

Question 8

Which has inflammation? FAP or HNPCC

Answer 8

HNPCC

Question 9

What is HNPCC associated with?

Answer 9

Gastric and endometrial carcinomas

Question 10

What is FAP associated with

Answer 10

Desmoid tumours and thyroid carcinomas

Question 11

Number of polyps - FAP

Answer 11

> 100

Question 12

Number of polyps - HNPCC

Answer 12

<100

Question 13

What age do people who suffer from FAP/HNPCC die?

Answer 13

Around 30

Question 14

What is the major type of colorectal cancer?

Answer 14

Adenocarcinoma

Question 15

Adenocarcinoma cause

Answer 15

Mutation of APC and K-ras

Question 16

Investigations of adenocarcinomas

Answer 16

FOBT, Colonoscopy + biopsy (GLD STD), CT colonoscopy (for staging), barium enema

Question 17

What does barium enema XR show?

Answer 17

Apple-core legion

Question 18

What does histology show?

Answer 18

Dirty necrosis, surrounding tissue to mass a different colour

Question 19

What staging is used?

Answer 19

Dukes

Question 20

Dukes A and 5y survival?

Answer 20

Confined by muscularis mucosa - 90%

Question 21

Dukes B and 5y survival?

Answer 21

Through muscularis mucosa - 60%

Question 22

Dukes C and 5y survival?

Answer 22

Lymph node mets - 30%

Question 23

Dukes D and 5y survival

Answer 23

Distant mets - 3%

Question 24

Treatment of adenocarcinoma

Answer 24

1. Surgery if dukes A, B (or C)
   - colectomy + lymph node removal
   - abdo-perineal resection
2. Radiotherapy + Chemo (palliative) - Dukes D

Question 25

Chemo drugs used for adenocarcinoma

Answer 25

5-FU adjuvant

Question 26

Clinical presentation of left-sided colorectal cancer

Answer 26

Rectal bleeding, altered bowel habit, obstruction, tenesmus

Question 27

Clinical presentation of right-sided colorectal cancer

Answer 27

Anaemia, weight loss

Question 28

Left-sided colorectal cancer affects..

Answer 28

Rectum, sigmoid and descending colon

Question 29

Right-sided colorectal cancer affects...

Answer 29

Caecum, ascending colon

Question 30

Is left or right-sided colorectal cancer more common?

Answer 30

Left (75%)