Colorectal Cancer Flashcards
What is the most common type of benign colorectal tumours
Adenomas
What is the most common type of malignant colorectal tumours
Adenocarcinomas
What do normal oncogenes do?
Promote cell growth and division
What do abnormal oncogenes do?
Cause excess cell growth and division (gain of function)
What do normal tumour suppressor genes do?
Suppress cell growth and division
What do mutated tumour suppressor genes do?
Allow cell growth and division (loss of function)
What are 3 macrocopic appearances of colorectal cancer
Polypoidal
Ulcerative
Annular (ring shaped)
Where is the most common site of cancer in the large bowel?
Rectum or sigmoid colon
Where is the least common site of cancer in the large bowel?
Descending colon
What are two different appearances of adenomas
Tubular and villous
What are the three different appearances of adenocarcinomas
Well differentiated
Moderately differentiated and
Poorly differentiated
What appearance of an adenoma is more likely to develop into an adenocarcinoma?
Villous
Describe the appearance of a well differentiated adneocarcinoma
Still looks like colonocytes
What are the two different methods of pathological staging
Dukes and TNM
Describe Duke’s stage C
A growth which has invaded throught hte muscle wall nad has metastasised to the lymph nodes
Where is colorectal cancer most likely to metastasise to?
Liver or lungs
What is a typical symptom of ascites
An everted umbilicus
What are the main two causes of colorectal cancer
Environemnt
Genetic factors
What are 3 protective lifestyle factors for colorectal cancer?
Vegetables
Gibre
Exercise
What are 4 causative lifestyle factors for colorectal cancer
Red and processed meat
Smoking
Alcohol
Obesity
What is the only treatment for FAP polyps?
Removing the colon
What are 3 predisposing conditions for Colorectal cancer
Adenomatous polyps
Ulcerative colitis
Crohn’s disease
What are the symptoms for ascending colon cancer and why
Anaemia - early blood loss
Often asymptomatic
What are the symptoms for descending colon cancer
Pain
change in bowel habit
rectal bleeding
What are symtpoms for colorectal cancer
Significant rectal bleeding
Tenesmus
What are 4 ways of diagnosing primary disease
Barium enema
CT colography
Sigmoidoscopy
Colonoscopy
What is a method of removing colonic cancer via colonoscopy
Snare
What does FOBT stand for
Faecal Occult Blood Testin
When is FOBT used?
Screening device in the healthy population
It detects around 70% of cancers
What are the emergency presentations of colorectal cancer?
Distension Constipation Pain Vomiting Bleeding
What can be the diagnosis of an emergency presentaiotn
Obstruction
Bleeding
Perforation
What are 3 ways in which we can treat an obstruction
Colostomy
Resection and colostomy
Stenting
What are the prognosis rates for differentiated cells
Good for well differentiated
Moderate for moderately differentiated
Poor for poorly differentiated
What are the treatments for colorectal cancer
Surgery
Radiotherapy
Chemotherapy
When would radiotherapy be used
After Surgery (not alone)
What are the 3 different surgical prcedures for rectal cancer?
Abdominal-perineal excision
Anterior resection
Local excision
What is the difference between abdominal-perineal excision and anterior resection
More of the colon is removed in abdominal-perineal excision. The sphincter is saved in anterior resection
How can we prevent colorectal cancer
Diet and lifestyle
How can we improve early detection of colorectal cancer
Heightened awareness
Screening
What other ways can we improve the survival rates of colorectal cancer
High quality surgery
Appropriate use of RT and Chemo
New agents for advanced disease
