Gastrointestinal Cancers Flashcards
Define cancer
A term for diseases in which abnormal cells divide without control and can invade nearby tissues
What is a primary cancer?
A cancer arising directly from cells in the organ
What is a secondary cancer?
A cancer that spreads from another organ, directly or by other means (blood or lymph)
What are the 6 main hallmarks of cancer?
Sustaining proliferative signalling Evading growth suppressors Activating invasion and metastasis Enabling replicative immortality Inducing angiogenesis Resisting cell death
What are the epithelial cell GI cancers?
Squamous cell carcinoma
Adenocarcinoma
What are the neuroendocrine GI cancers?
Neuroendocrine tumours
Gastrointestinal stromal tumours
What are the connective tissue GI cancers?
Leiomyoma/leiomyosarcoma
Liposarcoma
Where in the GI tract do neuroendocrine tumours occour?
Anywhere along the tract
Define cancer screening
Testing of asymptomatic individuals to identify cancer at an early stage
What criteria is used to decide if it is useful to screen for a disease?
Wilson Junger criteria
How is screening for colorectal cancer carried out?
FIT= faecal immunochemical test which detects haemoglobin in the faeces
One off sigmoidoscopy
How is screening for oesophageal cancer carried out? And for which patients?
Regular endoscopy for patients with Barrett’s oesophagus, low or high grade dysplasia
How is screening for pancreatic and gastric cancer carried out?
No test currently as it doesn’t meet the W & J criteria
How is screening for hepatocellular cancer carried out?
Regular ultrasound and AFP for high risk patients and those with cirrhosis
What is the first step in a cancer journey?
Presenting to the GP with symptoms or being identified via a screening programme
What happens after cancer is initially suspected?
Patients are referred via 2 week wait pathway
In the cancer MDT what is role of pathologist?
Confirm cancer diagnosis using biopsy samples
Provide histological typing eg where does the cancer come from
Provide molecular typing eg what mutations does the cancer have
Provide the tumour grade
In the cancer MDT what is role of radiologist?
Review scans
Suggest other imaging to clarify diagnosis
Decide if a biopsy needs to be performed and where
Provide tumour stage
Re staging after treatment
In the cancer MDT what is role of surgeon?
Decide if surgery is appropriate
Perform operation and care for patient after the operation
In the cancer MDT what is role of gastroenterologist?
Endoscopy, either diagnostic or therapeautic
In the cancer MDT what is role of oncologist?
Decides on whether chemotherapy, radiotherapy or other systemic therapy is appropriate
Co ordinates overall treatment plan
What is the major driver for gastric adenocarcinoma?
Chronic gastritis due to chronic acid overproduction
Describe the pathogenesis of gastric adenocarcinoma
Chronic gastritis, intestinal metaplasia, dysplasia and malignancy
What is the main symptom gastric adenocarcinoma presents with?
Dyspepsia (upper abdominal discomfort after eating or drinking)
What acronym is used to remember red flags of gastric adenocarcinoma and what does it stand for?
ALARMS55 Anaemia Loss of weight or appetite Abdominal mass on examination Recent onset of progressive symptoms Melaena or haematemesis Swallowing difficulty 55 years and above
How is gastric adenocarcinoma diagnosed?
Via endoscopy or biopsy
How is gastric adenocarcinoma treated if the tumour is close to the OG junction?
Total gastrectomy (the sphincter mechanism cannot be saved)
How is gastric adenocarcinoma treated if the tumour is at the OG junction?
Oesophago-gastrectomy
How is gastric adenocarcinoma treated if the tumour is far from the OG junction?
Subtotal gastrectomy
What types of chemotherapies can be used for gastric adenocarcinoma?
Neoadjuvant= to shrink tumour before surgery Adjuvant= needed in advanced tumours to reduce risk of relapse
Where do neuroendocrine tumours arise from?
The gastreoenteropancreatic tract (stomach, bowel, pancreas) or from the bronchopulmonary system
How do NETs present?
Most are asymptomatic and found incidentally
What may NETs detrimentally secrete?
Hormones (and their metabolites), mainly serotonin
What syndrome occurs when NETs secrete serotonin?
Carcinoid syndrome
What is required for carcinoid syndrome to arise?
Liver mets as without these the liver would metabolise the excess serotonin
What occurs in carcinoid syndrome?
Vasodilation causing face flushing Bronchoconstriction Increased intestinal motility causing diarrhoea Endocardial fibrosis (particularly right sided)
What are the 2 results of a pancreatic cancer?
Insulinoma
Glucagonoma
What are clinical features of insulinoma?
Hypoglycaemia
Whipples triad
What is Whipple’s triad?
A set of criteria that indicates someone is suffering from hypogylcaemia:
Has symptoms of hypoglycaemia
Symptoms are relieved by giving IV glucose
Fasting hypoglycaemia
What are clinical features of glucagonoma?
Diabetes mellitus
Erythema
What is insulinoma often misdiagnosed as?
Epilepsy because when blood sugar is low they faint and have seizures, their partners may also think they are drinking as hypoglycaemia makes you act like you are drunk
How are NETs diagnosed?
Biochemical assessment
Imaging eg CT/MRI
How are NETs graded?
By their mitoses and Ki-67 index
Where do GEP NETs most commonly metastasise?
Small intestine, pancreas and colon
How are NETs treated?
Mainly via resection
May need liver transplant if their are mets
Embolisation, medical therapy, targeted therapy or biotherapy may also be done
What are structural causes of upper dysphagia?
Pharyngeal cancer
Pharyngeal pouch
What are neurological causes of upper dysphagia?
Parkinson’s
Stroke
Motor neuron disease
What are structural causes of lower dysphagia?
Inside (mural and luminal): oesophageal or gastric cancer, stricture, Schatzki ring (hypertrophy of mucosa)
Outside (extrinsic compression): lung cancer
What are neurological causes of lower dysphagia?
Achalasia
Diffuse oesophageal spasm
How can we differentiate between angina and dysphagia?
Angina can occour after meals but will also usually occour after exertion
Dysphagia will also cause discomfort seconds after swallowing
How do you differentiate between upper or lower oesophageal dysphagia?
If food is painful on swallowing its upper
If food is easy to swallow but feels stuck seconds later its lower
How do you differentiate between mechanical and neurological causes of dysphagia?
If both liquids and solids are hard to swallow its likely neurological
What can you ask to determine if the patient is at risk of strictures?
History of reflux
What happens to albumin levels in anorexia?
May be low/slightly low
What are causes of microcytic anaemia?
Iron deficiency
Anaemia of chronic disease
Thalassaemia
Sideroblastic anaemia
What are causes of normocytic anaemia?
ABCDE: Aplastic anaemia Bleeding Chronic disease Destruction (haemolysis) Endocrine disorders (hypo or hyperthyroidism)
What are causes of macrocytic anaemia?
FAT RBC Foetus (pregnancy) Alcohol excess Thyroid disorders Reticulocytosis B12/folate deficiency Cirrhosis
What are some common GI causes of iron deficiency anaemia?
Aspirin/ NSAID use
Colonic adenocarcinoma
Gastric carcinoma
Benign gastric ulcer
What symptoms suggest colorectal cancer?
Change in bowel habit
Blood or mucus in stool
Faecal incontinence
Tenesmus
What is done to ensure the patient hasn’t missed blood in stool or urine?
Digital rectal exam
Urine dipstick test
How are cancers of the colon treated?
Via surgery to do resection
Accompanied by aggressive chemo and aggressive treatment in general as there are high rates of survival
