GI Cancers Flashcards
What is cancer?
The 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
Primary: arising directly from cells in an organ
Secondary: spread from another organ, directly or by other means
What are the hallmarks of cancer? What are the six biological capabilities acquired by tumours?
Sustaining proliferative signalling
Evading growth surpressors
Activating invasion and metastasis
Enabling replication immortality
Inducing angiogenesis
Resisting cell death
(Deregulating of cellular energetics)
(Avoiding immune destruction)
Enabling characteristics:
Tumour promoting inflammation
Genome instability and mutation
What types of cancer arise in the GI tract?
Epithelial cells:
Squamous -> squamous cell carcinoma
Glandular epithelium-> adenocarcinoma
Neuroendocrine cells:
Enteroendocrine cells -> neuroendocrine tumours (NETs)
Intestinal cells of cajal -> gastrointestinal stromal tumours (GISTs)
Connective tissue:
Smooth muscle -> leiomyoma/ leiomyosarcoma
Adipose tissue -> liposarcomas
What is cancer screening?
Testing of asymptomatic individuals to identify cancer at an early stage (higher survival rates)
how do you know what diseases are suitable for screening? Wilson and Jungner criteria - criteria include having available treatment, recognisable early stage, suitable test/examination…
Depends on the epidemiology of the disease and features of the test
What screening exists for GI cancers?
Colorectal: (offered to healthy people)
Faecal immunochemical test (FIT) - haemoglobin in shit, every 2 years age 60-74
One off sigmoidoscopy - everyone over 55 to remove polyps
Oesophageal:
Regular endoscopy to patients with Barrett’s oesophagus, low-high grade dysplasia
Pancreatic/gastric:
No test that exists meets the W and J criteria
Depends on incidence, Japan does screen
Hepatocellular:
Regular ultrasound and AFP for high risk individuals with cirrhosis: viral hepatitis, alcoholic hepatitis
(There are other screening processes for high risk individuals with genetic predisposition/family history)
What are the stages in a patients cancer journey?
Diagnosis: symptoms and signs, how is the diagnosis made
Staging: investigations to see how advanced the cancer is
Treatment: surgical removal? Chemo or radiotherapy?
What is the pathway of someone who has cancer?
Initial presentation - worrying symptoms to GP or doctor OR screening programme is positive
->
Patient is referred through the 2 week wait cancer pathway (not a waiting list, everything has to be done in two weeks)
->
Diagnostic tests
->
Multi disciplinary team
->
Treatment
Who are the members of the cancer MDT?
Pathologist
Radiologist
Palliative care
Gastroenterologist
Oncologist
Surgeon
Cancer nurse specialist
What does a pathologist do?
Confirms the diagnosis of cancer using biopsy samples
Provide histologic typing i.e. what type of cell does the cancer come from? (See second slide for cancer types)
Provides molecular typing i.e. what mutations does this Cancer have (can help determine type of treatment)
Provides the tumour grade i.e. how aggressive is the cancer (determined by how abnormal cells and their nuclei are, and how actively they divide)
What does a radiologist do?
Reviews scans - if diagnosis unclear, can scan confirm cancer. Can suggest other imaging to clarify, should a biopsy be performed?
Provides radiological tumour stage i.e. how far has the cancer spread. TNM system is used (size, lymph nodes, metastases)
Provides re staging after treatment. Did it respond completely or partially? Has it remained stable or progressed?
Interventional radiology. Percutanous biopsies, radiological stents
What do the surgeons and gastroenterologists do?
Tend to work together
Surgeon:
Decides whether surgery is appropriate. Is the tumour resectable? Is the patient fit enough for surgery?
Performs operation and cares for patient in preoperative period
Gastroenterologist:
endoscopy - diagnostic and therapeutic
Upper GI - oesophageal and gastric biopsies. Oesophageal stents
Liver and pancreas - ERCP and EUS biopsies. Biliary stents
Lower GI - colonic biopsies. Colonic stents
What does the oncologist do?
Decide on whether chemotherapy, radiotherapy or other systemic therapy is appropriate - this is determined by the scans, histological and molecular type. Also is the patient fit enough for full therapy
Coordinate the overall treatment plan. Should chemotherapy come before surgery (neoadjuvant) or after (adjuvant)? - takes into consideration: type, grade and stage. Patient fitness (performance status) and wishes
MDT decides where the plan should be for radical (curative) or palliative therapy or palliative care
What is the pathogensis of oesophageal cancers? (Squamous cell carcinoma and adenocarcinoma)
Squamous cell carcinoma:
Upper 2/3
Develops from normal oesophageal squamous epithelium
Commonest in developing world
Adenocarcinoma:
Lower 1/3 of oesophagus
Squamous epithelium that has become columnar (meta plastic)
Related to acid reflux
Commonest in developed world
Oesophagitis (due to GORD) may become Barrett’s oesophagus. This can turn into adenocarcinoma (neoplasia)
How do oesophageal cancers present?
Dysphagia - difficulty swallowing is commonest symptom
Late presentation - 65% at an advanced stage when diagnosed. This pretty much Leads palliative treatment
Why? -
Significant cancer growth needs to occur before dysphagia develops
Often have metastases
Most patients deemed unfit for surgery at diagnosis (malnourished)
This shows the importance of screening patients with reflux disease or Barretts oesophagus
How are oesophageal cancers diagnosed and staged?
Upper GI endoscopy (OGD) - if lesion is found -> biopsy taken to confirm a diagnosis
Investigations used to stage cancer:
CT of chest and abdomen
PET CT scan to exclude metastases
Staging laparoscopy - to identify liver and peritoneal metastases
Endoscopic ultrasound - via oesophagus to clarify depth of invasion and involvement of local lymph-nodes
