11.11 - Gastrointestinal Cancers Flashcards
Define cancer.
- a term for diseases in which 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 primary cancer?
Arising directly from the cells in an organ
What is secondary cancer?
Spread from another organ, directly or by other means (blood or lymph)
What are the six hallmarks of cancer? (Biological capabilities acquired by tumours)
- sustaining proliferative signalling
- evading growth suppressors
- activating invasion and metastases
- enabling replicative immortality
- inducing angiogenesis
- resisting cell death
What are the two emerging hallmarks of cancer? (Underlie hallmarks)
- deregulating cellular energetics
- avoiding immune destruction
What are the two enabling characteristics? (Underlie hallmarks)
- genome instability and mutation
- tumour-promoting inflammation
What are some facts about cancer?
- cancer is a genetic disease
- cancers contain multiple genetic errors
- cancers contain more than just malignant cells e.g. there will be neurovasculature, connective tissue, fibrous tissue
- killing cancer cells is easy
- ONLY killing cancer cells is hard
- developing novel therapies for cancer has many problems
What epithelial cell cancers of the GI tract are there and for which epithelial cell type?
- squamous cells - squamous cell carcinoma (SCC)
- glandular epithelium - adenocarcinoma
What neuroendocrine cell cancers of the GI tract are there and for which neuroendocrine cell type?
- enteroendocrine cells - neuroendocrine tumours (NETs)
- interstitial cells of Cajal - gastrointestinal stromal tumours (GISTs)
What connective tissue cancers of the GI tract are there and for which type of tissue?
- smooth muscle - leiomyoma / leiomyosarcomas
- adipose tissue - liposarcomas
What is cancer screening?
- testing of an asymptomatic individuals to identify cancer at an early stage
- specific screening programmes exist for those with genetic predisposition or strong family histories e.g. those with familial adenomatous polyposis (FAP) have multiple polyps in large bowel + increased cancer risk = offer colon resection to remove polyps or sigmoidoscopies to check for duodenal polyps
What are the seven Wilson and Jungner criteria for seeing which diseases are suitable for screening?
- the condition sought should be an important health problem
- there should be an accepted treatment for patients with recognised disease
- facilities for diagnosis and treatment should be available
- there should be recognisable latent or early symptomatic stage
- there should be a suitable test / examination
- the test should be acceptable to the population
- the natural history of the condition, including development from latent to declared disease, should be adequately understood
What is the screening for colorectal cancer?
- offered to healthy individuals
- faecal immunochemical test (FIT) - detects Hb in faeces, every two years for everyone aged 60-74
- one-off sigmoidoscopy - for everyone aged >55 to remove polyps (reducing future risk of cancer)
What is the screening for oesopheageal cancer?
Regular endoscopy to patients with Barrett’s oesophagus and low-to-high grade dysplasia
What is the screening for pancreatic and gastric cancer?
- no test exists that meets the W&J criteria
- depends on incidence - Japan screens for gastric cancer
What is the screening for hepatocellular cancer?
Regular ultrasound and AFP for high-risk individuals with cirrhosis e.g. by viral hepatitis or alcohol hepatitis