GASTROINTESTINAL CANCERS Flashcards
Which cancers arise from epithelial cells?
Squamous cell carcinoma - squamous epithelium
Adenocarcinoma - glandular metaplastic columnar epithelium
Which cancers arise from neuroendocrine cells?
Neuroendocrine tumours (NETs) - enteroendocrine cells Gastrointestinal stromal tumours (GISTs) - interstitial cells of Cajal
Which cancers arise from connective tissue?
Leiomyoma/leiomyosarcomas - smooth muscle
Liposarcomas - adipose tissue
How does alcohol increase risk of oesophageal cancer?
Via the acetaldehyde pathway (metabolism of alcohol which produces acetaldehyde - a carcinogen)
What part of the oesophagus does SSC affect?
upper 2/3
What part of the oesophagus does adenocarcinoma affect?
lower 1/3
What is oesophageal adenocarcinoma related to?
Acid reflux
Describe the steps from acid reflux to oesophageal adenocarcinoma
Oesophagitis - inflammation from GORD
Barrett’s - metaplasia 5% of GORD population
Adenocarcinoma - neoplasia
What are the stages of progression of Barrett’s oesophagus to adenocarcinoma which can be seen on biopsy?
Dysplasia (low grade)
Dysplasia (high grade)
Adenocarcinoma
How often do the different stages of dysplasia for Barrett’s need to be surveilled?
No dysplasia - every 2/3 years
LGD - every 6 months
HGD - intervention (likely invasive cancer)
What population does oesophageal cancer affect?
elderly with adenocarcinoma 10:1 male:female
How does oesophageal cancers present?
Late presentation with dysphagia and weight loss
Palliation is difficult and must rely on stents
What is the prognosis for oesophageal cancer patients?
High morbidity and a complex surgery
65% of patients palliative
5-year survival < 20% even with surgery
How are oesophageal cancers diagnosed?
Endoscopy then biopsy to confirm
What procedures can you undertake to stage oesophageal cancers?
CT scan
Laparoscopy - check metastases
Maybe endoscopic ultrasound if cancer is submucosal/not in visible in lumen
Maybe PET scan to pick up on metastases that aren’t seen by other imaging
How are oesophageal cancers treated?
Curative:
Squamous cell carcinoma- radiotherapy usually
Adenocarcinomas - neo-adjuvant chemo then surgery
Palliative (65%):
- Chemo
- DXT
- Stent
What is a surgical procedure for oesophageal adenocarcinomas?
2 stage Ivor Lewis oesophagectomy:
- Remove upper part of stomach
- Open chest and resect malignant oesophagus
- Rejoin stomach and oesophagus
What is the most common GI cancer in western societies?
Colorectal cancer
What age group does colorectal cancer tend to affect?
> 50 years
What is the lifetime risk for men and women
1/10 for men
1/14 for women
3rd most common cancer death
What are the 3 forms of colorectal cancer?
Sporadic - acquired, older population, isolated lesion
Familial - genetics (relative is usually close), more risk if < 50 years
Hereditary syndrome - genetics, younger age of onset, specific gene defects.
What are some examples of hereditary syndrome colorectal cancer?
Familial adenomatous polyposis (FAP)
Hereditary nonpolyposis colorectal cancer (Lynch syndrome)
What is the histopathology of colorectal cancer?
Adenocarcinoma
What are the risk factors for colorectal cancer?
Past history of colorectal cancer, adenoma, ulcerative colitis, radiotherapy
Family history
Diet/Environmental - smoking, obesity etc.
How does a left sided and sigmoid colorectal carcinoma present?
PR bleeding and mucus Thin stool (late) Bowel obstruction (late)
How does a rectal colorectal carcinoma present?
PR bleeding and mucus
Tenesmus (wanting to poop but nothing comes out)
Anal/perineal/sacral pain (late)
Bowel obstruction (late)
How does a caecal and right sided carcinoma present?
Iron deficiency anaemia - tumour more likely to bleed
Change of bowel habit (diarrhoea)
Distal ileum obstruction (late) Palpable mass (late)
How will a late local invasion of colorectal cancer present?
Bladder symptoms
Female genital tract symptoms
How will a late metastasis of colorectal cancer present?
Liver (hepatic pain, jaundice, hepatomegaly) Lung (cough, monophonic wheeze) Regional lymph nodes Peritoneum (sister Mary Joseph nodule) Bone pain
What are some signs that a colorectal cancer is primary?
Abdominal mass (late) < 12 cm from pectinate/dentate line Abdominal tenderness and distention - large bowel obstruction
List the tests that can be done to investigate colorectal cancer
Faecal occult blood (blood invisible in poo)tests:
- Guaiac test
- Faecal immunochemical test (FIT)
Blood tests:
- FBC (anaemia, haematinics, ferritin)
- Tumour markers (not diagnosis tool) e.g. CEA for
monitoring
Describe the guaicac test
Test for colorectal cancer based on pseudoperoxidase activity of haematin
Must avoid red meat, melons, horse-radish, vitamin C and NSAIDs for 3 days before test
What imaging can be done to investigate colorectal cancer?
Colonoscopy
CT colonoscopy/colonography
Pelvic MRI for rectal cancer
CT chest/abdo/pelvis
Why is colonoscopy done for colorectal cancer patients?
Can see lesions < 5mm
Small polyps can be removed to reduce cancer incidence
Performed under sedation
Why is CT colonoscopy/colonography done for colorectal cancer patients?
Can see lesions > 5mm
No need for sedation and less invasive/better tolerated than normal colonoscopy
However if lesions are identified patient will still nee colonoscopy for diagnosis
Why is pelvic MRI done for rectal cancer patients?
Check depth of invasion and mesorectal lymph node involvement.
No bowel prep or sedation
Helps to choose between preoperative chemo/radiotherapy or straight to surgery
Why is CT chest/abdo/pelvis done for rectal cancer patients?
Staging prior to treatment
How is colorectal cancer managed?
Primarily surgery
Stent/radiotherapy/chemotherapy to give time to plan surgery
How would an obstructing colon carcinoma in the right and transverse colon be treated?
Resection and primary anastomosis
How would a left sided obstructing colon carcinoma be treated?
Hartmann’s procedure with/out reversal in 6 months
Primary anastomosis with intraoperative bowel lavage (occasionally done)
- might first do defunctioning ileostomy to allow colon to
heal after resection
Palliative stent
What is Hartmann’s procedure?
Resect away tumour and surrounding colon then join proximal bowel to abdominal skin forming proximal end colostomy
List the surgical procedures for resection of a right sided cancer and the parts resected
Right hemicolectomy - caecum and ascending colon
Extended right hemicolectomy - portion of transverse colon too
Name the surgical procedure for resection of a left sided cancer and the parts resected
Left hemicolectomy - descending colon
If a patient has rectal cancer what is resected?
Part of rectum and part of sigmoid colon
What is the most common form of pancreatic cancer?
Pancreatic ductal adenocarcinoma (PDA)
Why should pancreatic cancer be taken seriously?
80-85% have late presentation and 5 year survival is 0.4-5%
Only 15-20% have a resectable disease and virtually all patients are dead with 7 years of surgery
What are the risk factors for pancreatic cancer?
Chronic pancreatitis (inflammation, healing cycle) T2DM Cholelithiasis Previous gastric surgery Pernicious anaemia Diet Occupation (insecticides...) Smoking Family history
What are some inherited syndromes associated with increased pancreatic cancer risk?
Hereditary pancreatitis Familial atypical multiple mole melanoma Familial breast-ovarian cancer syndrome Peutz-Jeghers syndrome HNPCC (lynch syndrome) FAP
How does pancreatic ductal adenocarcinoma (PDA) evolve?
PDAs evolve through non-invasive neoplastic precursor lesions called pancreatic intraepithelial neoplasias (PanIN 1/2/3)
These are similar to colorectal polyps and are microscopic
What is the PanIN progression model?
PanIN 1
PanIN 2
PanIN 3 (step before pancreatic cancer)
How would a carcinoma of the head of the pancreas present?
Jaundice (invasion or compression of common bile duct)
Weight loss (malabsorption, diabetes)
Pain (sign of locally invasive)
Acute atypical attack pancreatitis (rare) Vomiting (advanced - duodenal obstruction) GI bleeding (duodenal invasion/varices secondary to portal/splenic vein occlusion)
What does pain radiating to the back in a patient with pancreatic cancer signify?
Basically inoperable since it is now extraperitoneal due to posterior capsule invasion
How would a carcinoma of the body and tail of the pancreas present?
Develops insidiously and asymptomatic in early stages
When diagnosed much more advanced than pancreatic head lesions
Marked weight loss
Back pain
Vomiting (late stage invasion of DJ flexure)
Most unresectable at time of diagnosis
What are the investigations for pancreatic cancer?
Tumour marker CA19-9 Ultrasonography Dual-phase CT MRI MRCP ERCP EUS Laparoscopy + laparoscopic ultrasound PET
What does a tumour marker CA19-9 test show?
Falsely elevated in pancreatitis, hepatic dysfunction and obstructive jaundice. Concentrations > 200 U/ml = 90% sensitivity
What is the purpose of ultrasonography in pancreatic cancer?
Identifies:
- Pancreatic tumours
- Dilated bile ducts
- Liver metastases
What is the purpose of dual-phase CT in pancreatic cancer?
Predicts resectability, looks at:
- Contiguous organ invasion
- Vascular invasion
- Different metastases
What is the purpose of MRI in pancreatic cancer?
Detects and predicts resectability - similar to CT
What is the purpose of MRCP in pancreatic cancer?
Provides ductal images without complications of ERCP
What is the purpose of ERCP in pancreatic cancer?
Confirms typical ‘double duct’ sign
Aspiration/brushing of bile duct system
Therapeutic modality
Allows you to take biopsies to confirm diagnosis
What is the purpose of EUS in pancreatic cancer?
Detection of small tumours
Assessing vascular invasion
Fine needle aspirations to look at cells
What is the purpose of laparoscopy + laparoscopic ultrasound in pancreatic cancer?
Detect radiologically occult metastatic lesions of liver and peritoneal cavity
What is the purpose of PET in pancreatic cancer?
Mainly for demonstrating occult metastases
If a tumour is present at the head of the pancreas what is the surgical procedure?
Whipple’s resection - head of pancreas, gall bladder, duodenum, distal bile duct
If a tumour is present at the tail of the pancreas what is the surgical procedure?
Distal pancreatectomy - tail of pancreas, splenic artery and spleen
What are 4 cancers that can affect the liver?
Hepatocellular cancer (HCC) (primary liver cancer)
Colorectal cancer liver metastases
Cholangiocarcinoma
Gall bladder cancer
Name two potential causes of hepatocellular carcinoma
Cirrhosis (70-90%)
Aflatoxin
What is the median survival for hepatocellular carcinoma without treatment?
4-6 months
List the treatments for hepatocellular carcinoma
Liver transplant
Transcatheter arterial chemoembolisation (TACE)
Radiofrequency ablation (RFA)
Surgical excision (optimal curative)
Why are only 5-15% of hepatocellular carcinoma patients suitable for surgery?
Most patients have cirrhosis which limits the amount of liver you can take away as they still need some functioning organ
What are the causes for gallbladder cancer?
Aetiology unknown but associated with…
Gall stones:
- porcelain GB (chronic inflammation - calcification)
- chronic typhoid infection
What is the median survival for gallbladder cancer without treatment?
5-8 months
List the treatments for gallbladder cancer
Surgical excision
5 year survival: stage II 64%, stage III 44%, stage IV 8%
Systemic chemotherapy ineffective
What are some potential causes for cholangiocarcinoma?
Primary sclerosing cholangitis (PSC)
Ulcerative collitis
Liver fluke (worms)
Coledochal cyst
What is the median survival for cholangiocarcinoma without treatment?
< 6 months
List the treatments for cholangiocarcinoma
Surgical excision
5 year survival rate 20-40%
Systemic chemotherapy ineffective
What is cholangiocarcinoma and where is it usually found?
Cancer of bile duct an cells most commonly found at bifurcation of common hepatic duct
What is the survival rate of secondary liver metastases e.g. colorectal cancer without treatment?
< 1 year
List the treatments for secondary liver metastases e.g. colorectal cancer
Surgical excision
5 year survival rate 20-50%
