Gastrointestinal Cancers Flashcards
What is the definition of cancer?
a disease characterised by the uncontrolled division of abnormal cells in the body
What type of cancer tends to arise from squamous epithelial cells?
squamous cell carcinoma
What type of cancer tends to arise from glandular epithelial cells?
adenocarcinoma
What type of cancer tends to arise from enteroendocrine cells?
neuroendocrine tumours (NETs)
What type of cancer tends to arise from interstitial cells of Cajal cells?
Gastrointestinal Stromal Tumours (GISTs)
What type of cancer tends to arise from smooth muscle cells?
Leiomyoma/leiomyosarcomas
What type of cancer tends to arise from adipose tissue cells?
Liposarcomas
What population is most affected by colorectal cancer?
> 50 years old men
What is the most common GI cancer in the west?
Colorectal cancer
What are the different forms of colorectal cancer?
- sporadic
- familial
- hereditary syndrome
What is the sporadic form of colorectal cancer?
- Absence of family history
- Older population
- Isolated lesion
What is the familial form of colorectal cancer?
Family history, higher risk if:
- index case is young (<50years)
- the relative is close (1st degree)
What is the hereditary syndrome form of colorectal cancer?
- Family history
- Younger age of onset
- Specific gene defects
e. g. - Familial adenomatous polyposis (FAP)
- Hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome)
How do people with Familial adenomatous polyposis present?
- young polyps
- removals of lots of the large colon at a young age
What is thought to prevent the progression of polyps to colorectal cancers?
aspirin
What are the risk factors of developing Colorectal cancers?
PMHx - colorectal cancers - adenoma, ulcerative colitis, radiotherpy FHx - first degree relative - genetic predisposition Lifestyle - smoking - obesity - socioeconomic status - carcinogenic foods
Where does colorectal cancer occur?
- 2/3 - descending colon, rectum
- 1/2 - sigmoid colon and rectum (seen on sigmoidoscopy)
How does caecal and right sided cancer present?
- iron deficiency anaemia
- diarrhoea
- distal ileum obstruction (late)
- palpable mass (late)
How does sigmoid and left sided cancer present?
- PR bleeding
- mucus
- thin stools (late)
How does rectal cancer present?
- PR bleeding
- mucus
- tenesmus (urge to poo but being unable to)
- anal, perineal and sacral pain
- bowel obstruction (late)
What are the late signs of local invasion of a carcinoma?
- bladder symptoms
- female genital tract symptoms
What are the late signs of metastasis of a carcinoma?
- liver: hepatic pain, jaundice
- lung: cough
- regional lymph nodes
- peritoneum: sister mary joseph nodule
What are the signs of primary colorectal cancer?
- abdominal mass
- digital rectal examination: most < 12cm from dentate line and reached by finger
- rigid sigmoidoscopy
- abdominal tenderness and distension (large bowel obstruction)
What are the signs of metastasis and complications of colorectal cancer?
- hepatomegaly
- monophonic wheeze
- bone pain
How do you diagnose colorectal cancer?
- FIT (faecal immunochemical test) for occult blood
- FBC: anaemia, haematinitcs, low ferritin
- tumour markers: CEA (NOT a diagnostic tool)
How do you investigate colorectal cancer?
- colonscopy
- CT colonoscopy/colonography
- MRI pelvis
Why is a colonscopy used to investigate colorectal cancer?
- can visualize lesions <5mm
- small polyps can be removed
- reduced cancer incidence
- performed under sedation
Why is a CT colonoscopy/colonography used to investigate colorectal cancer?
- can visualize lesions >5mm
- no need for sedation
- less invasive, better tolerated
- colonoscopy is still needed for diagnosis if lesions are identified
- useful for elderly patients
Why is a MRI pelvis used to investigate colorectal cancer?
- depth of invasion
- mesorectal lymph node involvement
- no bowel prep or sedation required
- help choose between preop chemoradiotherapy or straight to surgery
What scans are used to stage a colorectal cancer prior to treatment?
CT chest/abdomin/pelvis
How do you manage an obstructing colon carcinoma in the right and transverse colon?
- resection
- primary anastomosis
How do you manage an obstructing colon carcinoma in the left sided colon?
- Hartmann’s procedure (emergency operation)
- Primary anastomosis
- Palliative stent
What arteries supply the right and transverse colon?
- Iliocolic
- Right colic
- Middle colic
What arteries supply the left sided colon?
- branches of inferior mesenteric artery:
- Left colic
- sigmoid arteries
What happens in a Right Hemicolectomy?
- right side of the large bowel
- removing the ascending colon, caecum
- connecting the terminal ileum, to the transverse colon
What happens in a Extended Right Hemicolectomy?
- remove 2/3 or the large bowel (caecum, ascending colon and part of the transverse colon)
- connect terminal ilium to the remainder of the transverse colon
What happens in a Left Hemicolectomy?
- remove the descending colon
- connect transverse colon to the sigmoid colon via anastomosis
How do you resect with rectal cancer?
- remove the rectum and part of the sigmoid colon
- connect the remaining colon (sigmoid) to the anus
What is normally done instead of a resection with rectal cancer?
iliostomy
What is the most common form of pancreatic cancer?
pancreatic ductal adenocarcimona
When does pancreatic cancer tend to present?
- late (80-85%)
- only 15-20% have resectable disease
When does pancreatic cancer tend to occur?
between 60-80 years of age
What are the risk factors of pancreatic cancer?
- chronic pancreatitis (18 fold risk)
- T2DM
- cholelithiasis
- previous gastric surgery
- pernicious anaemia
- diet (high in fat, protein, coffee and etOH)
- occupation (chemical and metal exposure)
- smoking
- family history (hereditary pancreatitis)
What are pancreatic intraepithelial neoplasias?
- microscopic (<5mm)
- not visible by pancreatic imaging
- evolve through non-invasive neoplastic precursor lesions
What happens in the development of pancreatic ductal adenocarcinomas?
they acquire clonally selected genetic and epigenetic alterations along the way
How does a carcinoma at the head of the pancreas present?
(2/3)
- Jaundice
- Weight loss
- Pain
- acute pancreatitis
- GI bleeding
- vomiting
What causes jaundice with a carcinoma at the head of the pancreas?
- invasion or compression of the common bile duct
- painless
- Courvoisier’s sign (palpable gallbladder)
What causes weight loss with a carcinoma at the head of the pancreas?
- anorexia
- malabsorption (due to exocrine insufficiency)
- diabetes
What causes pain with a carcinoma at the head of the pancreas?
- epigastrium
- radiates to the back
What does back pain with a carcinoma at the head of the pancreas indicate?
- posterior capsule invasion
- irresectability
What does vomiting with a carcinoma at the head of the pancreas indicate?
duodenal obstruction
What does GI bleeding with a carcinoma at the head of the pancreas indicate?
- duodenal invasion
- varices (due to portal or splenic vein occlusions)
How does a carcinoma at the body and tail of the pancreas present?
- asymptomatic at the early stages
- weight loss
- back pain
- vomiting
- unresectable at time of diagnosis
- jaundice unlikely
What does vomiting with a carcinoma at the body and tail of the pancreas indicate?
(late) - invasion of the DJ flexure
What investigations can be done with pancreatic cancer?
- Tumour marker: CA19-9
- Abdominal ultrasound
- Dual-phase CT
- MRI
- MRCP
- ERCP
- EUS
- laparoscopy and laparascopic US
- PET
What does the Tumour marker: CA19-9 indicate?
- falsely elevated in: pancreatitis, hepatic dysfunction and obstructive jaundice
- conc. >200U/ml = 90% sensitivity
- conc. > 1000 = high sensitivity
What can an ultrasonography detect?
- identify pancreatic tumours
- dilated bile ducts
- liver metastases
What can a dual-phase CT detect?
- accurately predict resectability in 80-90% of cases
- contiguous organ invasion
- vascular invasion (coeliac axis and SMA)
- distant metastases
What can an MRI detect?
detects and predicts resectability with accuracies similar to a CT
What can an MRCP detect?
provides ductal images without ERCP complications
What can an ERCP detect?
- confirms the typical double duct sign
- aspiration/brushing of the bile-duct system
- therapeutic modality - biliary stenting to relieve jaundice
What can an EUS detect?
- highly sensitive in the detection of small tumours
- assesses vascular invasion
- FNA
What can a laparoscopy and laparoscopic US detect?
radiologically occult metastatic lesions of liver and peritoneal cavity
What can a PET detect?
demonstrates occult metastases
When do you do a whipple resection?
when the carcinoma is at the head of the pancreas
What is a whipple resection?
- remove: distal bile duct, gall bladder, distal stomach, all of the duodenum until the jejunum starts
- bile duct, stomach and remaining pancreas attach to the small intestine
What is a TOP resection?
remove distal part of pancreas (tail and body), spleen
What are the 4 different types of liver cancer?
- Hepatocellular cancer
- Cholangiocarcinoma
- Gall Bladder cancers
- Colorectal cancer liver metastases
Where does hepatocellular cancer occur?
in the hepatocytes of the liver itself
What can cause hepatocellular carcinoma?
- cirrhosis (from alcohol or Hep B)
- aflatoxin
Where does Cholangiocarcinoma occur?
- bile ducts, the bifurcation of the common hepatic duct
How do you treat hepatocellular cancer?
(chemo is ineffective) Optimal is surgical excision with curative intent - liver transplant - transarterial haemoembolisation - radiofrequency ablation
What is associated with gallbladder cancer?
- gallstones
- porcelain gall bladder
- chronic typhoid infections
How do you treat gallbladder cancer?
- surgical excision with curative intent
- chemo is ineffective
What is the 5 year survival rate of gallbladder cancer?
stage 2: 64%
stage 3: 44%
stage 4: 8%
What is thought to cause Cholangiocarcinoma?
- choledochal cyst
- ulcerative colitis and primary scloerosing cholangitis
- liver flukes
How do you treat Cholangiocarcinoma?
surgical excision with curative intent
How do you treat secondary liver metastases?
- surgical excision with curative intent
- chemo improving
How do you surgically resect a hepatocellular cancer?
remove the affected part of the liver (as little as possible)
How do you surgically resect a gallbladder cancer?
remove the gallbladder, all the lymphnodes, liver tissue surrounding
How do you surgically resect a Cholangiocarcinoma?
remove the half of the liver with the tumour
What are the differentials for pain swallowing?
- upper abdominal
- lower abdominal
- cardiac
- other
What are the causes of upper abdominal dysphagia?
- structural: pharyngeal cancer or puch
- neurological: parkinson’s, stroke, motor neurone disease
What are the causes of lower abdominal dysphagia?
- structural: oesphogeal or gastric cancer, stricture, lung cancer
- neurological: achalasia, diffuse oesophageal spasm
What is the cardiac cause for difficulty swallowing?
Post-prandial angina
What is post prandial angina?
- angina which occurs after meals
- caused by blood shifting to bowel for digestion which limits blood supply through coronary arteries
- occurs on exertion
What symptoms differentiate upper and lower abdominal dysphagia?
- upper = pain on swallowing
- lower = easy swallowing but feels stuck seconds later
What indicates a neurological cause of dysphagia rather than mechanical?
Both solids and liquids are hard to swallow
What indicates a GI malignancy?
Blood in stool
What are the different types of microcytic anaemia?
MCV <80
1. Iron deficiency anaemia
2. Anaemia of chronic disease
3. Thalassaemia
4. Sideroblastic anaemia
What are the different types of normocytic anaemia?
MCV 80-96
Aplastic anaemia
Bleeding
Chronic disease
Destruction (haemolysis)
Endocrine disorders (hypothyroidism, hypoadrenalism)
What are the different types of macrocytic anaemia?
MCV >96
Foetus (pregnancy)
Alcohol excess
Thyroid disorders
Reticulocytosis
B12/Folate deficiency
Cirrhosis
What is iron deficiency anaemia caused by?
- increased demand
- decreased absorption
What are the GI causes of iron deficiency anaemia?
- aspirin/NSAIDs
- colonic adenocarcinoma
- gastric carcinoma
What is the main non-GI cause of iron deficiency anaemia?
Menstruation
What symptoms that might suggest colorectal cancer?
- Change in bowel habit
- Blood or mucus in stool
- Faecal incontinence
- Tenesmus
Symptoms that might suggest an upper GI cancer?
- Dysphagia
- Dyspepsia
What does Malena indicate?
upper GI bleeding
What does bright red PR bleeding indicate?
- lower GI bleeding
- haemorrhoids
What does blood and stool mixed indicated?
large colon issues
What tests would you do if colorectal cancer is suspected?
- Urine dipstick (haematuria?)
- Iron studies (confirm iron deficiency as the cause of microcytic anaemia)
- anti-TTG (coeliac screening)
- urgent colonoscopy through the 2-week-wait suspected cancer pathway. - - If negative, an upper GI endoscopy will be organised
What qualifies you for the 2-week wait suspected cancer colonoscopy?
blood in the stool
What tests need to be done to decide on a treatment plan for a descending colon adenocarcinoma?
- Staging CTCAP
(metastases picked up easily) - MRI liver, pelvis
How do you manage a descending colon adenocarcinoma T3N0M1?
- resect primary colonic tumour/colonic stent
- neoadjuvant chemotherapy
- liver resection
What do NETs arise from?
Gastroenteropancreatic tract
What are NETs?
- diverse group of tumours
- all arise from the secretory cells of the neuroendocrine system
- secrete hormones
What are the causes of NETs?
- sporadic
- genetic (multiple endocrine neoplasia type 1)
What does multiple endocrine neoplasia type 1/MEN1 cause?
- parathyroid tumours
- pancreatic tumours
- pituitary tumours
What is the presentation of NETs?
- most are asympotmatic and found incidentally
- secretion of horomones and metabolites (serotonin, tachykinins, vasoactive peptides)
- carcinoid syndrome
What are the symptoms of carcinoid syndrome?
- vasodilaton
- bronchoconstriction
- increased intestinal motility
- endocardial fibrosis
What are the different types of NETs?
- insulinoma
- glucagonoma
- gastrinoma
- VIPoma
- somatostanioma
- non-functioning midgut tumour
- non-functioning hindgut tumour
How are NETs diagnosed?
- biochemical assessment
- imaging
What is screened for in a biochemical assessment?
- Chromogranin A (secretion of NETs)
- fasted gut hormones ( insulin, gastrin, somatostatin, PPY)
- calcium
- PTH
- prolactin
- GH
- serotonin metabolite 5-HIAA
What imaging is done for NETs?
- CT
- MRI
- (capsule) endoscopy
- barium flow through
- endoscopic US
- somatostatin receptor scintigraphy
What is the main treatment for NETs?
Curative resection
