GI Cancers Flashcards
Describe types of oesophageal cancer
Squamous cell carcinoma - upper 2/3. From normal oesophageal squamous epithelium. Goes through acetaldehyde pathway (ethanol broken down by alcohol dehydrogenase into oxidised acetaldehyde and then oxidised to acetate by acetaldehyde dehydrogenase). More common in less developed world.
Adenocarcinoma - lower 1/3. Related to acid reflux and develops from metaplastic epithelium. More common in more developed world.
Describe progression from reflux to cancer
Oesophagitis (inflammation - GORD). Barrett’s (metaplasia). Oesophageal cancer (neoplasia).
Describe progression from Barretts to cancer
Barrett’s leads to low grade dysplasia, then high grade, then adenocarninoma. Surveillance guidelines are:
No dysplasia → Every 2-3 years
LGD → every 6 months
HGD → intervention
Who does oesophageal cancer mainly affect?
Elderly, more males than females (adenocarcinoma), late presentation includes weight loss and dysphagia, management pathway (endoscopy and biopsy to diagnose, laparoscopy and CT to stage, surgery to cure)
How is an oesophagectomy carried out?
Using Ivor Lewis approach. Esophageal tumor is removed through an abdominal incision and a right thoracotomy (a surgical incision of the chest wall)
Who does colorectal cancer affect?
More men than women, people over 50, most common GI cancer in western society
What are forms of colorectal cancer?
Sporadic - no Fx, isolated lesion, older person
Familial - has family history, closer relative and younger family diagnosis means more risk
Hereditary - specific gene defect. Familial adenomatous polyposis (FAP), hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome)
Describe colorectal cancer development
Normal becomes hyperproliferative epithelium then small adenoma, large adenoma and finally carcinoma.
What are risk factors for colorectal cancer?
Past history - adenocarcinoma, ulcerative colitis
Family history - first degree relative below 55, relatives with genetic predisposition
Smoking, obesity, socioeconomic status
What is clinical presentation of caecal and right sided colon cancer?
Iron deficiency anaemia (most common) Change of bowel habit (diarrhoea) Distal ileum obstruction (late) Palpable mass (late)
What is clinical presentation of left sided and sigmoid carcinoma?
PR bleeding, mucus Thin stool (late)
What is clinical presentation of rectal carcinoma?
PR bleeding, mucus
Tenesmus
Anal, perineal, sacral pain (late)
What are late clinical signs of a metastases?
Liver (hepatic pain, jaundice) Lung (cough) Regional lymph nodes Peritoneum Sister Mary Joseph nodule
What are signs of primary cancer?
Abdominal mass
DRE: most <12cm dentate and reached by examining finger
Rigid sigmoidoscopy
Abdominal tenderness and distension – large bowel obstruction
What are signs of metastasis and complications?
Hepatomegaly (mets)
Monophonic wheeze
Bone pain