GI cancers Flashcards
What is a neoplasm
an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue, and which persists even after the evoking stimulus (if known) is removed
How do GI cancers cos obstruction of luminca
Intussusception , where polyp causes the bowel to telescope and drags the blood vessels in the mesentery along with it causing ischemia
what are the cytological features of malignancy
- High nucleus/cytoplasm ratio ⇒ Suggests proliferation
- Hyperchromasia ⇒ Production of nuclear material in DNA
- Pleomorphism ⇒ Irregular appearances of different aspects of cells
How to diff adenocarcinoma with adenoma histologically
Abnormal glands invading the wall of the colon with a stromal reaction
Symptoms of GI Neoplasms
- Tiredness (anaemia)
- Bleeding
- Anorexia and vomiting
- Weight loss
- Pain caused by obstruction
- Dysphagia
- Alteration in bowel habit
What genes are involved in the A-C sequence
k-ras( activated oncogene), p53(inactivated TSG)
What is the APC protein
encoded by APC (TSG), negative regulator that controls beta-catenin concentrations and interacts with E-cadherin, whichareinvolved in cell adhesion → Deletion of the APC gene predisposes to cancer.
what genes cause early adenoma and then intermediate adenoma
APC, then KRAS
what does TMN staging show
how far the cancer has spread ( extent)
what are T1, 2, 3, and 4 respectively in colon
Ti is LP till submucosa, T2 has reached muscularis propria, T3 reaches serosa, T4 reaches nearby organs
Common Lymph node areas for oseophageal cancer
Bifrucation of trachea
Most common type of oesophageal cancer in the UK and which part of the oesophagus does it occur in
Common risk?
Adenocarcinoma, lower 1/3 oesophagus
Obesity , associated with reflux
Risk factors for squamous cell carcinoma of oesophagus
- Smoking is major factor ⇒Tobacco
- Alcohol
- Diet and very hot beverages
- Infection
What are the main symptoms and presentations for oesophageal cancer
- VERY FEW symptoms until late-difficulty swallowing ⇒ New, progressive dysphagia for solids first then liquids
- More likely in elderly
- May present with heartburn and increasing dysphagia
- May also have regurgitation and weight loss
- Advanced cancer may present with hoarse voice due to
- Left recurrent laryngeal nerve infiltrated in advanced tumour
Investigations and diagnosis fo oescophageal cancer
Endoscopy, then biopsy for diagnosis
- CT thorax and abdomen ⇒ Check for Metastases and Lymph Nodes around tumour
- May need more specialised testing like PET scanning
Endoscopic ultrasound to stage tumour ⇒ give info about depth of tumour
treatment for oeso cancer
If T3N1M0 for example, patient deemed fit for surgery and can have preoperative chemotherapy followed by surgery
Palliation if treatment nor possible
- Improve quality of life ⇒ swallowing ( using stent) and maintaining weight
- Re-establish connection between healthy bit of oesophagus and stomach
Is gastric cancer more common in males or females
More common in males
What germline mutations may contribute to gastric cancer
TP53, CDH 1 genes
Aetiology of gastric cancer
multifactorial: diet, H. pylori, bile reflux ⇒ Anything that causes chronic gastritis
Can gastric cancer cause melena
Yes, because of ulceration which can bleed
What are the two main histological patterns of gastric adenocarcinoma
Intestinal ( obvious gland formation) and diffuse (signet ring cells)