10: Colorectal cancer Flashcards
Colorectal cancer is the 2nd most common cause of cancer ___.
death
What is the benign form of colorectal neoplasia?
Adenoma
What is the malignant form of colorectal neoplasia?
Adenocarcinoma
What are adenomas a subset of?
Polyps
Polyps can also be ___.
inflammatory
What are two types of genes associated with cancer?
Oncogenes
Tumour suppressor genes
Oncogenes promote ___ ___ and ___ when normal.
cell growth
division
When mutated, oncogenes cause ___ cell growth and division.
excessive
Tumour suppressor genes ___ cell growth and division when normal.
suppress
What happens when tumour suppressor genes mutate?
Cell growth and division no longer suppressed
uncontrolled “”
Name an example of a tumour suppressor gene associated with colorectal cancer.
APC
Name an example of an oncogene involved in colorectal cancer.
K-Ras
slide 19
tubular - fissures
villous - seaweed-like fronds
Adenocarcinomas can be well, moderately or poorly ___.
differentiated
Which two staging systems are used to classify the progression of colorectal cancer?
Dukes
TNM
Describe a Dukes A tumour.
Hasn’t invaded the muscle wall
Describe a Dukes B tumour.
Tumour has invaded the muscle wall but no lymph nodes are involved
Described a Dukes C tumour.
Tumour has invaded muscle wall and lymph nodes are involved
Describe a Dukes D tumour.
Distant metastases
By what means can colorectal cancer spread?
Local (i.e via adjacent structures)
Lymphatically
Blood (liver and lungs specifically)
Transcoelomic (into the peritoneal cavity)
Treatment of colorectal cancer must take into consideration the ___ ___ involved.
lymph nodes
What lifestyle factors protect against colorectal cancer?
Diet (high fibre, fruit and veg)
Exercise
What lifestyle factors cause colorectal cancer?
Red, processed meat
Smoking
Alcohol
Obesity
A large family history of colorectal cancer (increases / decreases) the chances of developing it yourself.
increases
What is FAP?
Familal adenomatous polyposis
an inherited form of colorectal cancer.
What is the clinical presentation of FAP?
shitloads of polyps
What is HNPCC?
Hereditary nonpolyposis colorectal cancer
i.e FAP without all the polyps
Name two inherited forms of colorectal cancer.
What mode of inheritance do they have?
FAP , HNPCC
Autosomal dominant
Which GI conditions predispose you to cancer?
Adenomatous polyps
Crohn’s disease
Ulcerative colitis
___ inflammation is associated with the onset of colorectal cancer.
Chronic
What general condition is caused by substantial bleeding in the GI tract?
Anaemia
Why do colorectal cancer patients experience tenesmus?
Literally a mass in their rectum which can’t be evacuated
What are common symptoms of colorectal cancer?
Bleeding - rectal, anaemia, with diarrhoea
Abdominal pain
Altered bowel habits
Tenesmus
Weight loss
How is suspected colorectal cancer investigated?
Barium enema
CT scan
Sigmoid/colonoscopy
What can be used to remove polyps during an investigation?
Endoscope itself
What screening test can be used to detect colorectal cancer early?
Faecal occult blood test (FOBT)
50-75 year olds should have ___ ___ every two years.
bowel screening
Which investigations are used to stage the spread of colorectal cancer (e.g to the lungs and liver)?
CT scan
What is an emergency presentation of colorectal cancer?
Obstruction
Bleeding
Bowel perforation
What treatment is used to treat obstruction in the short term?
Colostomy / resection / stenting
The higher the Dukes stage, the (better / worse) the patient’s prognosis.
worse
Poorly differentiated cancer has a (good / bad) prognosis.
Well differentiated cancer has a (good / bad) prognosis.
poorly differentiated - poor prognosis
well differentiated - good prognosis
___ is often the treatment for colorectal cancer.
Surgery
What other treatments can be used to treat/palliate colorectal cancer?
Radiotherapy
Chemotherapy
The key to ensuring a better prognosis for colorectal cancer is to catch it ___.
early
