Bowel Cancer Flashcards
Describe the different stages of colon cancer
Stage 0 - Carcinoma in situ
Stage 1 - Invasion of the muscularis mucosa or into the muscularis externa (T1 and T2)
Stage 2 - Invasion beyond the muscularis externa or into adjacent organs (T3 and T4)
Stage 3 - T1-4 plus N1-2
Stage 4 - Stage 3 plus distant metastasis
How might colon cancer present?
Fe deficiency anaemia
Weight loss
Rectal bleeding
Bowel obstruction
Change in bowel habits
Abdominal pain
What does obstipated mean?
Not passing gas
What is the gene in FAP?
APC (adenomatous polyposis coli)
Which chemotherapy drugs can cause mucositis?
Fluorouracil
Capecitabine
Why do people with colon cancer perforate?
Bowel obstruction
Ulceration of the cancer
How many polyps do you require for the diagnosis of FAP?
>100
What are the three most common locations for a colon cancer to met to? How do you investigate for them?
LNs
Liver
Lungs
CT CAP with contrasts
How does the staging of rectal cancer differ from colon?
They can be down staged due to the use of neoadjuvant radiotherapy as the cancer location is fixed
What does the APC gene control?
Beta-catenin desmosomes
When is surgery indicated?
Stages I-III
What is the typical chemotherapy regimen for colon cancer?
Folinic acid
5FU
Oxaliplatin
What is Lynch syndrome/HNPCC? What is the most important defects? What other cancers does predispose people to?
Hereditary non-polyposis colon cancer
Causes a fault in DNA mismatch repair resulting in microsatellite instability
Endometrial, bladder, small bowel carcinomas
What is HNPCC?
Hereditary non-polyposis colon cancer syndrome
AKA Lynch syndrome
What is the T staging for colon cancer?
T1 - Lamina propria
T2 - Into the muscularis externa
T3 - Breaches the muscularis externa
T4 - Invaded surrounding viscera
What are the typical chemotherapy regimen options for stage III colon cancer?
Fluorouracil and folinic acid
Folfox - Fluorouracil, folinic acid, and oxaliplatin
Capecitabine
What does the surgery performed from each section of the colon?
Right - Right hemicolonectomy
Transverse - Right extended hemicolonectomy
Splenic flexure - Subtotal colonectomy (ileo-sigmoid anastomy)
Left - Left hemicolonectomy
Rectum - Low/Ultra low anterior resection
Which part of the bowel is most likely to perforate?
Caecum - largest portion > most tension per area of wall
When is chemotherapy indicated?
Stage II-IV
When does an adenoma become an adenomacarcinoma?
When it invades the lamina propria
What are the three sources of gas in a distended bowel obstruction?
Swallowed
Nitrogen diffusion
Bacterial production
Which type of bowel cancers are most likely to cause change in bowel habit and rectal bleeding?
Left sided and rectal as the stool is more formed there
How much iron can be adsorbed per day? How much iron is lost in a 1L of blood?
1mg
500mg
What is Gardener’s syndrome?
Subtype of FAP causing multiple skin tags
What are the revised Bethesda criteria for? Outline the criteria
Identifying patients who warrant screening for Lynch syndrome
CRC <50
Present of synchronous or metachronous HPNCC related carcinomas regardless of age
CRC with specific features <60 years
CRC in 1 or more FDR with HPNCC or <50
CRC in 2 or more first or second degree relatives regardless of age
How do you test for Lynch/HPNCC?
Immunohistochemistry staining on tumour tissue for mismatch repair proteins
What pathological features are associated with CRC with mismatch repair mutations?
Synchronous development
Right sided tumours
Mucinous or signet ring differentiation
Medullary growth pattern
Lymphocytic infiltrate
Peritumour Crohn’s like lymphocytic infiltrate
What are the techniques available for screening for Lynch’s?
IHC
Microsatellite Instability Analysis
