Colorectal Tumours

Question 1

what are colorectal polyps

Answer 1

projections arising from the mucosal surface of the colon, they may be non-neoplastic or neoplastic; histology needed to confirm the nature

Question 2

what are colorectal cancers

Answer 2

malignant adenocarcinomas of the large bowel

Question 3

what is the distribution of locations of colorectal cancers

Answer 3

60% - sigmoid colon and rectum
30% - descending colon
10% - rest of the colon

Question 4

aetiology

Answer 4

environmental and genetic

Question 5

risk factors for developing colorectal cancers

Answer 5

family history, western diet (red meat, alcohol etc), colorectal polyps, previous colorectal cancer, IBD, male sex and increasing age

Question 6

why may IBD lead to colorectal cancer

Answer 6

chronic inflammation increases risk of malignancy

Question 7

epidemiology

Answer 7

second greatest cause of cancer deaths in the West, in the UK it causes 20000 deaths/yr and the average age of diagnosis is 60-65

Question 8

presenting symptoms of colorectal cancers

Answer 8

left sided colon and rectum:
change in bowel habit, rectal bleeding, tenesmus

right sided colon;
presents later than left sided, anaemia symptoms, weight loss, non-specific malaise, lower abdominal pain (rare)

Question 9

what is tenesmus

Answer 9

feeling as though you need to pass stool despite empty bowels

Question 10

why may tumours present as an emergency with abdominal pain and distension

Answer 10

20% present as an emergency with pain and distension due to large bowel obstruction (colicky pain and change in bowel habit) or haemorrhage/ peritonitis due to perforation (persistent pain and bleeding)

Question 11

physical examination findings

Answer 11

anaemia,
abdominal mass,
if metastatic- abdominal mass and ascites (shifting dullness)
If low lying rectal tumour- tumour may be palpable on DRE (digital rectal examination)

Question 12

investigations

Answer 12

bloods (FBC for anaemia, LFT's, Tumour markers such as CEA)
stool (FOBT)
endoscopy (biopsy to send to histology)
double contrast barium enema 
contrast CT

Question 13

what is FOBT

Answer 13

faecal occult blood test to test the stool for blood

Question 14

significance of CEA

Answer 14

high level of CEA can be a sign of certain types of cancers. These include cancers of the colon and rectum, prostate, ovary, lung, thyroid, or liver