GI Cancers Flashcards
Whats the difference between a primary cancer and a secondary cancer?
Primary cancer: arising directly from the cells in an organ
Secondary: spread from another organ, directly or by other means
What are the 6 hallmarks of cancer?
Sustaining proliferative signalling Evading growth suppressors Activating invasion and metastasis Enabling replicative immortality Inducing angiogenesis Resisting cell death
What 4 factors underlie the hallmarks of cancer?
Deregulating cellular energetics
Avoiding immune destruction
Tumour- promoting inflammation
Genome instability and mutation
What are different types of cancers that can be found in the GI tract?
Epithelial cells:
Squamous cell carcinoma
Adenocarcinoma
Neuroendocrine cells:
Neuroendocrine tumours
Gastrointestinal stromal tumours
Connective tissue:
Leiomyoma/ leiomyosarcomas
Liposarcomas
Which GI cancer has the best prognosis?
Colorectal
Which GI cancer has the worst prognosis?
Pancreatic
What is the purpose of cancer screening?
Tests asymptomatic individual to identify cancer at early stage
To decide which diseases are suitable for screening- Wilson and Jungner criteria
Depends on epidemiology of the disease and features of the test
What screening options are there for colorectal cancer?
Offered to healthy individuals:
Faecal immunochemical test (FIT)- detects haemoglobin in faeces, every 2 years for everyone ages 60-74
One off sigmoidoscopy for everyone aged >55 to remove polyps (reducing future risk of cancer)
What screening options are there for oesophageal cancer?
Regular endoscopy to patients with:
Barrett’s oesophagus
Low- high- grade dysplasia
What screening options are there for pancreatic and gastric cancer?
No tests exist that meet W&J criteria
Depends on incidence
What are screening options for hepatocellular cancer?
Regular ultrasound and AFP for high risk individuals with cirrhosis:
- viral hepatitis
- alcoholic hepatitis
What are examples of specific screening programmes for individuals with genetic predispositions or strong family histories?
Individuals with hereditary pancreatitis (caused by mutation in CFTR, PRSS1 AND SPINK1) have a 40-50% risk on pancreatic cancer so need to be screened regularly
Individuals with familial adenomatous polyposis (FAP) have many polyps. They are at high risk of cancer so have routine colonoscopies and sigmoidoscopes and perhaps a prophylactic resection (removal of organ/ part of organ before cancer to reduce risk of cancer)
What is the journey a cancer patient takes?
Initial presentation- through screening programme or referral
Patient is referred through 2-week-wait cancer pathways
Diagnosis tests
MDT
Treatment
What individuals may be involved in the cancer multi-disciplinary team?
Pathologist Cancer nurse specialist Surgeon Radiologist Palliative care Gastroenterologist Oncologist
What is the role of the pathologist?
- Confirms diagnosis of cancer using biopsy
- Provides histological typing, i.e. what type of cell cancer comes from:
- non-epithelial cells less common in GI tract
- Epithelium (squamous cell carcinoma) or secretory cells (adenocarcinoma)
- Neuroendocrine tumours
- Gastrointestinal cancer - Provides molecular typing i.e. what mutations does this cancer have? It can also determine types of treatment available
- Provides tumour grade- determined by how abnormal cells are and their nuclei are and how actively they are dividing
What is the role of the radiologist?
Reviews scans:
- if diagnosis is unclear comment on how likely scan is to confirm cancer
- suggest other imaging to clarify suspected diagnosis
- should a biopsy be performed and where?
Provides radiological tumour stage i.e. how far has it spread? :
- T size of tumour
- N lymph node involvement
- M presence of metastasis
Provides re-staging after treatment:
- has cancer responded completely or partially?
- has it stayed stable or progressed?
Interventional radiology
- percutaneous biopsies
- radiological tests
What is the role of the surgeon?
Decides whether surgery is appropriate
Performs operation and cares for patient in preoperative period
What is the role of the gastroenterologist?
Endoscopy- therapeutic and diagnostic: Upper GI - oesophageal and gastric biopsies -oesophageal stents Liver and Pancreas -ERCP and EUS biopsies -Biliary stents Lower GI -Colonic biopsies -Colonic stents
What is the role of the oncologist?
Decides whether chemotherapy, radiotherapy or other systemic therapy is appropriate
- determined by scans, histology and molecular types
- is the patient fir for full intensity therapy?
Coordinates the overall treatment plan- should chemo come before surgery (nonadjuvant) or after (adjuvant). Considers:
- type, grade, stage
- patient fitness and wishes
MDT decided whether plan should be radical (curative) or palliative therapy (tying to extend life) or palliative care (no treatment)
What is the pathogenesis of oesophageal cancer?
Squamous cell carcinoma:
Upper 2/3 of oesophagus
Develops from normal oesophageal squamous epithelium
commonest in developing world
Adenocarcinoma: Lower 1/3 of oesophagus Squamous epithelium that has become columnar (metaplastic) Related to acid reflux Commenest in developed world
What are different conditions that can increase the risk of oesophageal cancer?
Oesophagitis- affects 30% of population, due to GORD
Barrette’s oesophagus (intestine metaplasia)- occurs in 5% of pts with GORD. Metaplasia can lead to mild/moderate/severe dysplasia which can lead to cancer
Adenocarcinoma (neoplasia)- occurs in 0.5-11% patients with Barrett’s per year
These can increase risk of cancer by 30-100 fold
How does oesophageal cancer present?
Dysphagia (difficulty swallowing) is comments symptom
Late presentation- 65% at an advanced stage when diagnosed- palliative treatment
Why do so many patients present with oesophageal cancer late?
Significant cancer growth needs to occur before dysphagia develops
Often have metastsis
Most patients deemed unfit for surgery at diagnosis
How is oesophageal cancer diagnosed and screened?
Upper GI endoscopy (OGD)- if lesion found, biopsy is taken to confirm diagnosis
Investigations to stage the cancer:
- CT of chest and abdomen
- PET-CT scan to exclude metastases
- Staging laparoscopy- to identify peritoneal metastasis
- Endoscopic ultrasound- via oesophagus to clarify depth of invasion and involvement of local lymph nodes
What are treatment options for oesophageal cancer?
If tumour is surgically resectable with no distant metastasis and patient is fit for surgery:
- Curative: neoadjuvant chemotherapy- oesophagectomy
If not:
-Palliative: palliative chemotherapy and steroids and stent
What is the pathogenesis of gastric cancer?
Gastric adenocarcinoma
Chronic gastritis is the major driver:
- H. pylori infection- due to chronic acid overproduction
- Pernicious anaemia- antibodies against parietal cells
- Partial gastrectomy- leading to bile reflux
- Epstein- Barr virus
Family history (inc, heritable diffuse-type gastric cancer) due to E-cadherin mutations) High salt diet and smoking
What is the presentation of gastric cancer?
Dyspepsia (upper abdominal discomfort after eating or drinking) commonest symptom Red flags: ALARMS55 Anaemia Loss of weight or apetite Abdominal mass on examination Recent onset of progressive symptoms Melaena (black stool) or haematemesis (vomiting blood) Swallowing difficulty 55yrs old or above
How is gastric cancer diagnosed and staged?
Diagnosis: endoscopy and biopsy
Staging:
- CT of chest, abdomen and pelvis
- PET-CT
- Diagnostic laparoscopy- for peritoneal and liver metastasis disease prior to full operation
- Endoscopic ultrasound- will give most detail about local invasion and node involvement
What are treatment options for gastric cancer?
Oesophageal- gastrectomy: for tumour at oesophago- gastric junction
Non-adjuvant chemotherapy (shrink tumour before surgery)
Subtotal gastrectomy- further from OG junction
Total gastrectomy- close to OG junction
Adjuvant chemotherapy (in advanced tumours to reduce relapse risk)
