Gastrointestinal Cancer Flashcards
What is meant by primary cancer?
arising directly from the cells in an organ
What is meant by secondary cancer?
a metastatic cancer spread to another organ directly or by other means such as blood or lymph
Where does squamous cell carcinoma arise from?
from normal oesophageal squamous epithelium involving the acetaldehyde pathway
Where does adenocarcinoma arise from?
metaplastic columnar epithelium and is related to acid reflux
Outline the progression of reflux to cancer
inflammation from reflux to barretts metaplasia oesophagus to dysplasia to adenocarcinoma
How do we carry out Barretts oesophagus surveillance according to the BSG guidelines?
no dysplasia -> every 2/3 years have endoscopy
with low grade dysplasia -> carry out endoscopy every 6 months
high grade dysplasia -> intervene
What are the clinical signs of oesophageal cancer?
dysphagia and weight loss
How do diagnose gastrointestinal tract cancer?
endoscopy biopsy to determine adenocarcinoma vs squamous cell carcinoma etc
How do we stage gastrointestinal tract cancer?
CT scan
laparoscopy - for metastasises
oesophageal ultrasound
PET scan - to pick up other metastasises
How do we treat adenocarcinoma GI cancer?
neo adjuvant chemotherapy
radical surgery
palliative treatment - chemotherapy, radiotherapy, oesophageal stent
What are the forms of colorectal cancer?
sporadic - no family history
familial - family history of colorectal cancer
hereditary syndrome - family history, younger age of onset, specific gene defects
What are examples of colorectal cancer with a hereditary syndrome?
familial adenomatous polyposis
hereditary non polyposis colorectal cancer
Outline the pathogenesis of colorectal cancer
1 a normal epithelium with an APC mutation
2 leads to a hyperproliferative epithelium with an aberrant cryptic fold resulting in aberrant COX 2 overexpression which results in a small adenoma (polyp)
3 K-ras mutation can lead to the small adenoma forming a large adenoma
4 p53 mutation paired with loss of 18q results in colon carcinoma
How can aspirin, folate and calcium reduce risk of colorectal cancer
- by affecting APC mutation that leads to hyperproliferative endothelium
- aspirin can inhibit COX preventing a small adenoma
- aspirin can inhibit K-ras mutation resulting in reduced risk of large adenoma
What are the risk factors for colorectal cancer?
family history - identified genetic predisposition such as FAP
past history - colorectal cancer, adenoma, ulcerative colitis, radiotherapy
diet/ environmental - ie carcinogenic foods, smoking, obesity, socioeconomic status
How does caecal cancer present clinically?
iron deficiency anaemia
change of bowel habit commonly diarrhoea
distal ileum obstruction
palpable mass
What is the difference between sigmoidscopy and colonoscopy
smaller endoscope only assessing sigmoid colon and rectal cancer
whereas colonscopy assess all of the colon
How does sigmoid carcinoma present?
PR bleeding and more mucus
very thin stool
What are symptoms of rectal carcinoma?
PR bleeding, mucus, anal perineal and sacral pain
tenesmus - feeling that you need to pass stool despite empty bowel
bowel obstruction
What are signs of local invasion?
bladder symptoms
female genital tract symptoms
distal rectal examination
metastasis - liver (jaundice, lung (cough) , regional lymph nodes, sister mary joseph nodule (umbilicus metastatic cancer that is visible)
What are the signs of primary cancer?
abdominal mass
rigid sigmoidscopy
abdominal tenderness and distension
How do we diagnose colorectal cancer?
FBC - showing anaemia and low ferritin
Tumour markers - CEA (but its not diagnostic alone)
guaiac test - to detect fecal occult blood
FIT - faecal immunochemical test which also detects faecal occult blood
How do we investigate colorectal cancer?
colonoscopy under sedation - can visualise lesions less than 5mm
small polyps can be removed to reduce the cancer incidence
or CT colonoscopy/colonography
What is CT colonoscopy/colonography?
less invasive and can visualise lesions greater than 5mm -> if lesions identified patient needs colonoscopy for diagnosis
What other imaging tests can be done for colorectal cancer?
Mri pelvis
CT chest, abdo, pelvis to exclude metastasis
How do we manage colorectal cancer?
right and transverse colon - resection and primary anastomosis
left side : hartmann’s procedure (colectomy and then giving a colostomy) which can be reversed
primary anastamosis - (intraoperative bowel lavage with primary anastomosis) resulting in a defunctioning ileostomy
palliative option - stent
Outline a right hemicolectomy
right colon removed then ileocolic anastomosis is formed
Outline an extended right hemicolectomy
right colon and portion of transverse colon is removed and ileocolic anastomosis is formed
Outline left hemicolectomy
removal of left colon and anastomosis with anus - but an ileostomy is preferred
What is the most common form of pancreatic cancer?
pancreatic ductal adenocarcinoma
What are the risk factor for pancreatic cancer?
chronic pancreatitis type 2 diabetes gallstones, pernicious anaemia poor diet occupation - exposure to acylamide, insecticides cigarette smoking family history
What are genes hereditary pancreatitis is associated with?
PRSS1 - cationic trypsinogen
SPINK1 - panc secretory trypsin inhibitor
CTFR
Outline the pathogenesis of pancreatic cancer
1 pancreatic intraepithelial neoplasia aka PanIN
PDAs evolve through non invasive neoplastic precursor lesions
2 PanIN’s are microscopic and not visible in pancreatic imaging
3 the PanIN’s acquire clonally selected genetic and epigenetic alterations along the way
How does pancreatic cancer present?
jaundice - palpable gallbladder weight loss - diabetes pain - epigastrium and back atypical attack of acute pancreatitis gastrointestinal bleeding
What investigations can be done for pancreatic cancer?
Tumour marker CA19-9 - falsely elevated in pancreatitis
ultrasonography - to identify pancreatic tumours, dilated bile ducts, liver metastases
dual phase CT
MRI
mrcp
ERCP - very useful
What can mrcp be used for in investigating pancreatic cancer?
provides ductal images without complications of ERCP
What can ercp be used for in investigating pancreatic cancer?
confirms the typical double duct sign
aspiration/brushing of the bile duct system
therapeutic modality -> biliary stenting to relieve jaundice
What can endoscopic ultrasound be used for in investigating pancreatic cancer?
highly sensitive in the detection of small tumour -> can assessing vascular invasion
and is useful for fine needle aspiration
What can laparoscopy and laparoscopic ultrasound be used for investigating pancreatic cancer?
detecting radiologically occult metastatic lesions of lier and peritoneal cavity
What can PET scan be used for investigating in pancreatic cancer?
PET mainly used for demonstrating occult metastases
Outline a head of pancreas resection
Ripples resection
Outline tail of pancreas resection
remove spleen and remove the splenic artery
What are the types of liver cancer?
hepatocellular carcinoma
cholangiocarcinoma
gallbladder carcinoma
colorectal cancer metastases
What is hepatocellular carcinoma often associated with?
70-90% have underlying cirrhosis
What is the most common and effective treatment for hepatocellular carcinoma?
liver transplant
What can cause gallbladder?
unknown but associated with gallstones, porcelain gall bladder and chronic typhoid infection
What can cause cholangiocarcinoma?
ulcerative colitis and primary sclerosing cholangitis
choledochal cysts
liver fluke
What are curative treatments for cholangiocarcinoma?
excising the treatment in surgery
