GI cancers Flashcards
What is cancer?
A term for diseases = abnormal cells divide without control and can invade nearby tissues
Cancer cells can also spread to other parts of the body through the blood and lymph systems
What is a primary cancer?
What is a secondary or metastasis cancer?
Arising directly from the cells in an organ
Spread from another organ, directly or by other means (blood or lymph)
What are the first 6 hallmarks of cancer?
6 biological capabilities acquired by tumours =
Sustaining proliferative signalling
Evading growth suppressors
Activating invasion and metastasis
Enabling replicative immortality
Evading angiogenesis - blood supply for growing tumour mass
Resisting cell death
What are the emerging hallmarks of cancer?
Deregulating cellular energetics
Avoiding immune destruction
What are the enabling characteristics of cancers?
What gives them selective advantage, acquired through genetic change AND/or epigenetic dysregulation (e.g. from chronic inflammation) =
Genome instability and mutation
Tumor promoting inflammation
What do we know about cancer?
Cancer is a genetic disease
Cancers contain multiple genetic errors
Cancers contain more than just malignant cells - stromal cells, neovascular cells etc.
Killing cancer cells is easy
ONLY killing cancer cells is very hard and not affecting the normal cells around them
Developing novel therapies for cancer fraught with problems
What are the cancers of the epithelial cells of the GI tract?
What are the cancers of the neuroendocrine cells of the GI tract?
What are the cancers of the connective tissue of the GI tract?
Squamous cell carcinoma - squamous
Adenocarcinoma - glandular epithelium
Neuroendocrine tumours - enteroendocrine cells
Gastrointestinal stromal tumours - interstitial cells of Cajal
Leiomyoma/Leiomyosarcomas - smooth muscle
Liposarcomas - adipose tissue
Where are GI neuroendocrine tumours found?
Throughout the GI tract, from the oesophagus to the stomach, duodenum pancreas, large bowel, small bowel and rectum
What is the most common GI cancer?
Why are GI cancers problematic?
Bowel (4th most common), but stomach, liver and pancreas cancer incidences are lower
2nd highest morbidity
Low incidence but high death rates
What is essential for lessening cancer morbidity?
Why is there a higher 5 year survival rate for colorectal cancer compared to pancreatic or oesophageal?
Cancer screening - catching the disease early = better chance of resecting it = better chance of 5 year survival after diagnosis
Large bowel = has a mesentery and keeps to itself
Other GI cancers e.g. pancreatic, oesophageal, gallbladder = involve other structures v. quickly
What is cancer screening?
Testing of asymptomatic individuals to identify cancer at an early stage
How do we identify whether a disease is suitable for screening?
Wilson & Jungner criteria
Depends on the epidemiology of a disease & features of the test:
The condition should be an important health problem - and affecting a significant number of people to make it cost-effective to offer the screenings
There should be an accepted treatment for patients with disease
Facilities for diagnosis and treatment should be available
There should be a recognisable latent or early symptomatic stage
There should be a suitable test or examination
The test should be acceptable to the population - not too unpleasant where the population does not turn up to the test
The natural history of the condition, including development from latent to declared disease should be adequately understood
How is colorectal cancer screened for?
Offered to healthy individuals:
Faecal immunochemical test (FIT) - detects haemoglobin in faeces, every 2 years for everyone aged 60-74
One-off sigmoidoscopy for everyone aged >55 to remove polyps (reducing future risk of cancer)
How is oesophageal cancer screened for?
Regular endoscopy to patients with:
Barrett’s oesophagus
OR
Have been found to previously had low- or high-grade dysplasia that has already been dealt with by local means rather than full resection for a full cancer
Are pancreatic and gastric cancers screened for?
No test exists that meets the W & J criteria
Depends on incidence - Japan screens for gastric cancer (high incidence): perform endoscopies
Makes economic and clinical sense to base this off incidence rate
How is hepatocellular cancer screened for?
Regular ultrasound & AFP (alpha faecal protein - tumour marker- looked for in a blood test) for high-risk individuals: With cirrhosis OR Viral hepatitis OR Alcoholic hepatitis OR NASH (non alcoholic steatotic hepatitis)
Who else is offered screening?
Specific screening programmes for those with genetic predisposition OR strong family histories
e.g. FAP (familial adenomatous polyposis) - multiple polyps in colon and duodenum, high risk of developing colorectal / duodenal cancer and so are offered prophylactic resections and yearly colonoscopies or OGD’s
OR
Hereditary pancreatitis - 40% lifetime risk of pancreatic cancer, offered prophylactic surgery and yearly imaging
What is the cancer journey?
Diagnosis - What symptoms and signs does the patient present with? How is the diagnosis made?
Staging - What investigations are needed to see how advanced the cancer is?
Treatment - Can the cancer be surgically removed? What systemic therapy (e.f. chemotherapy) or radiotherapy is available?
How does a patients journey with cancer and the cancer MDT start?
Initial presentation to a member of the MDT:
Worrying symptoms to GP or another doctor (e.g. A&E)
OR
The patient is identified through a screening programme (e.g. faecal occult blood test for colon cancer)
What happens next in the patient’s cancer journey involving the cancer MDT?
The patient is referred through the 2-week-wait cancer pathway
What is the third step in the cancer journey involving the Cancer MDT?
Diagnostic tests
What is the fourth step in the cancer journey involving the Cancer MDT?
MDT - MDT meeting in which diagnostic test results are discussed
What is the fifth step in the cancer journey involving the Cancer MDT?
Treatment