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Flashcards in Esophagus and GI Cancer Deck (14):
1

Describe the histology of Esophageal and GI cancers.

  • Esophageal cancer
    • Squamous cell: cells lining the esophageal lumen
    • Adenocarcinoma:  columnar cells that form glands
  • Gastric cancer
    • Adenocarcinoma
      • Intestinal
      • Diffuse

2

Differentiate between intestinal and diffuse type gastric cancers.

  • Intestinal: cohesive neoplastic cells that form glands and tubular structures (associated with intestinal metaplasia)
  • Diffuse: discohesive cells that invade individually
    • may lead to linitis plastica (associated with mucin production and signet rings)
    • linitis plastica is where the stomach can't stretch, so sense of fullness is quickly achieved with meals

3

What are the major risk factors for esophageal cancer?

  • Either histology  (SCC and adenocarcinoma)
    • Tobacco  (9x increase for SCC, 4x increase for AC)
    • Smokeless tobacco
    • Mediastinal radiotherapy
  • Squamous cell cancer
    • Tobacco (9x increase)
    • Alcohol (5x increase)
    • Both leads to a 20x increase!
    • A diet low in fruit and vegetables
    • Medical conditions
      • Tylosis
      • Plummer-Vinson syndrome
      • Achalasia
      • Celiac disease
      • HPV

4

What is Barett's esophagus and what is its role in esophageal cancer?

  • Barrett's esophagus is the acquired metaplasia of the transition zone between the squamous epithelium of the esophagus and the columnar cells of the stomach
    • GERD
    • achalasia
    • chemical injury
    • hiatal hernia
    • connective tissue disease
    • genetic factors
  • Clinical risk factors for Barretts metaplasia and adenocarcinoma
    • Male
    • Obese
    • > 45 years of age
    • Drug therapy (beta-ag, benzo)
    • > 8 cm of Barretts
    • H pylori absent
    • GER > 3 times/week
    • Heavy tobacco
    • GER for > 10 years
    • Mucosal damage
    • White
    • Low fruit and veg diet

5

What are the risk factors for gastric cancer?

  • Universal demographic factors
    • Increasing age
    • Male sex
    • Deprivation 
  • Environmental factors
    • H. Pylori
    • Medical disease
    • Tobacco
    • Stomach surgery
    • Diet
    • Blood group A
    • Occupation
    • Medications
    • Radiation
    • BMI
    • Alcohol
    • Age at menopause

6

What is H. pylori and its pathogenesis?

  • Gram negative microaerophilic bacterium
    • Acquired in childhood
    • Highest in developing world, decreasing in developed world
    • Infection
      • Inflammation
      • Chronic infection
      • Chronic gastritis, atrophic gastritis, gastric atrophy
      • Loss of HCl, pepsin, intrinsic factor
         

7

How does H. pylori increase risk for gastric cancer?

  • Loss of infection with onset of cancer
    • H pylori does not colonise areas of cancer, intestinal metaplasia, or atrophy
  • There is evidence that with the development of advanced gastric disease the organism can be lost from the stomach
  • An overall odds ratio (OR) of around three was shown for non-cardia stomach cancer
    • OR of around six for those who were tested for H. pylori ten or more years prior to the development of stomach cancer
    • Infection with cytotoxin CagA-positive H. pylori carries a higher risk than infection with CagA-negative strains

8

What are the common methods of workup for esophageal cancer?

  • T-stage:  EUS
    • dysphagia generally corresponds to T3
  • N-stage:  EUS, PET
    • mediastinal, celiac, not peritumoral
  • M-stage:  CT/MRI
    • not accurate for distant lymph nodes

9

What are the most important aspects of treatment planning for esophageal cancer?

  • 3 modalities for therapy
    • Chemotherapy
    • Radiation
    • Surgery
  • Factors to consider in treatment planning
    • Stage of disease
    • Performance status
    • Medical co-morbidites
    • Goals of care

10

What is the role of surgery in esophageal cancer?

  • Only complete microscopic resection is curative
  • Cervical and suprabifurcal
    • less likely to have complete resection
  • No correlation with extent of lymphadenectomy
    • 2 field: abdominal and mediastinal
    • 3 field: cervical, mediastinal and abdominal
  • Transthoracic or abdominal approach equivalent
  • Correlation with surgical experience

11

What is the role of surgery in gastric cancer?

  • Subtotal: proximal or distal if 5 cm margin
  • Total gastrectomy for all others
  • Pancreatectomy and splenectomy increases complications
  • D1-D4 lymph node dissection
    • D1 lesser and greater curvature, paracardial
    • D2 gastric, hepatic, celiac, splenic
    • D3 hepatoduodenal
    • D4 retropancreatic, root of mesentary, transverse mesocolon, paraaortic

12

What is the mechanism of trastuzumab?

  • Inhibits HER2-mediated signalling in HER2-positive tumors
  • Prevents HER2 activation by blocking extracellular domain cleavage
  • Activates antibody-dependent cellular cytotoxicity

13

What is TNM staging for esophageal cancer?

  • Tis
    • High grade dysplasia
  • T1
    • Invades submucosa
  • T2
    • Invades muscularis propria
  • T3
    • Invades adventitia
  • T4
    • Invades adjacent structures
  • T4a
    • Resectable (pleura, pericardium, diaphragm)
  • T4b
    • Unresectable (aorta, vertebral body, trachea)
  • N0
    • No regional lymph nodes involved
  • N1
    • 1-2 positive regional lymph nodes
  • N2
    • 3-6 positive regional lymph nodes
  • N3
    • ≥ 7 positive regional lymph nodes
  • M0
    • No metastases
  • M1
    • Distant metastases

14

What is TNM staging for gastric cancer?

  • Tis
    • Intraepithelial without invasion of the lamina propria
  • T1
    • Invades lamina propria or submucosa
  • T2a
    • Invades muscularis propria or subserosa
  • T2b
    • Invades subserosa
  • T3
    • Penetrates serosa (visceral peritoneum)
  • T4
    • Invades adjacent structures (spleen, transverse colon, liver, diaphragm, pancreas, abdominal wall, adrenal, kidney, small intestine, retroperitoneum)
  • N0
    • No regional lymph node metastases
  • N1
    • 1-6 regional lymph nodes involved
  • N2
    • 7-15 regional lymph nodes involved
  • N3
    • > 15 regional lymph nodes involved