Tumours: Colorectal Carcinoma Flashcards
It is usually a polypoid mass with ______. This spreads by ___ ____ . It involves ____ and ___ ___ .
It is usually a polypoid mass with ulceration. This spreads by direct infiltration through the bowel wall. It involves lymphatics and blood vessels.
what do they look like histologically ?
adenocarcinoma with variably differentiated glandular epithelium with mucin production
where are 75% of CRCs?
Left sided (rectum, sigmoid, descending)
where are 25% of CRCs?
25% Right sided (Caecum, Ascending)
what are the PCs for left sided? 3
p/c: Blood PR, Altered bowel habit, Obstruction
what are the PCs for right sided? 2 and why?
p/c: Anaemia, Weight loss - get more generalised symptoms because the tumour can grow quite large
what is in the centre of the glands? hallmark of CRC
dirty necrosis pattern
what is dukes A?
Dukes A: confined by muscularis propria
what is dukes B?
Dukes B: through the muscularis propria
what is dukes C?
Dukes C: metastatic to lymph nodes
what are some protective associations with colorectal cancer
vegetbles, fibre and EXERCISE
what are some associated causes of CRC
red and processed meat, smoking, alcohol and OBSESITY
how does exercise help?
exercise has a similar effect to the tumour suppressor gene ____ which stimulates the enzyme ____ responsible for a decrease in cell turnover and glucose uptake by muscle
LKB1, AMPK
what are the three types of macroscopic CRC appearances
polypoidal
ulcrative
annular
histologically it is an _______ with variably differentiated _____ epithelium with ____ production
is adenocarcinoma with variably differentiated glandular epithelium with mucin production
the majority of CRC are _____ in type
polypoid
what are some predisposing conditions for CRC ? 3
Adenomatous polyps
Ulcerative colitis
Crohn’s disease
clinical features depend on where the cancer is, if it is in the rectum what are the symptoms?
Rectal bleeding and tenesmus
if it is in the sigmoid what are the symptoms?
Pain,
change in bowel habit - stool become looser and get pseudo -diarrhoea
rectal bleeding
if it is in the caecum and right side what are the symptoms?
Anaemia - Tend not to get rectal bleeding but they become anaemic as they lose small amounts of blood over a long period of time
by far the most common cause of unexplained anaemia for both males and females is ____
CRC
what are the general findings on clinical examination?
Anaemia, cachexia and lymphadenopathy
what are the abdomen findings on clinical examination?
Mass, hepatomegaly and distension
what are the rectum findings on clinical examination?
mass and blood
what investigations are done?
FBC
- liver biochemistry
- renal function
- colonoscopy
- barium
- CT colography
- MRI scan - because CT scan of rectum is not great
how is it screened for?
FOBT
what are the emergency complications of CRC
obstruction
bleeding
perforation
what are the symptoms of obstruction
distension, constipation, pain and vomiting - the exact symptoms out of these 4 may vary depending on where the obstruction is
what are the treatment options for obstruction?
colostomy alone, resection and colostomy, resection and anastomosis but the commonest way nowadays is through stenting
what treatment may reduce local recurrence after a rectal excision?
radiotherapy
radiotherapy can be used ______
palliatively
examples of chemo
5 -fluorouracil or capecitabine
chemo is used for ____ disease
advanced
