Esophageal cancer pathophysiology
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Hadeel Maksoud M.D.[2]
Overview
The pathophysiology of esophageal cancer depends on the histological subtype, whether squamous cell carcinoma or adenocarcinoma.
Pathophysiology
- The esophagus is lined by nonkeratinized stratified squamous epithelium.
- This lining is maintained as long as there are no risk factors that can lead to a metaplastic change.
Esophageal Squamous Cell Carcinoma
- The risk factors for esophageal squamous cell carcinoma include smoking and alcohol.[1][2]
- When alcohol and tobacco are combined they have a synergistic effect and the risk for esophageal squamous cell carcinoma is higher.
- Alcohol is able to dissolve fat soluble compounds, like that of the esophageal epithelium.
- Tobacco carcinogens such as aromatic amines, nitrosamines and polycyclic hydrocarbons are, therefore, able to penetrate the esophageal epithelium deeper when in the presence of alcohol.
- Alcohol is also able to decrease the metabolic activities of epithelial cells by damaging DNA.
- When the cellular DNA is damaged, the cell cannot undergo detoxification and protect itself from oxidative damage.
- Oxidation leads to inflammation of the squamous epithelium.
- Continuous irritation of the epithelium leads to dysplasia and in situ malignant transformation.
Esophageal Adenocarcinoma
- The risk factors for esophageal adenocarcinoma include gastroesophageal reflux disease and obesity.[3][4][5][6][7]
- The chronic reflux of gastric acid and bile at the gastroesophageal junction leads to the irritation of squamous epithelium lining the esophagus.
- Chronic irritation leads to metaplasia of esophagus.
- The lining of the esophagus changes from non-keratinized stratified squamous epithelium to columnar epithelium.
- This condition is called Barrett's esophagus.
- The progression of Barrett metaplasia to adenocarcinoma is associated with several changes in gene structure, gene expression, and protein structure.
- Mutations in PT53 genes and P16 genes along with cell cycle abnormalities and aneuploidy have all been associated with the development of esophageal adenocarcinoma.
- In addition, obesity is implicated in the development of esophageal adenocarcinoma.
- Patients with central obesity tend to have hypertrophied adipocytes and inflammatory cells within their fat deposits.
- This creates a microenvironment within the adipocyte that promotes tumor development through the release of adipokines and cytokines.
- Adipocytes potentiate tumor expansion by supplying energy to support the tumor's growth.
Pathology
Gross pathology
Squamous cell carcinoma or adenocarcinoma of the esophagus may appear as:[8]
- Flat and irregular plaque
- Polypoid lesion
- Ulcerating, fungating mass.
- Location:
- Squamous cell carcinoma is usually found in the mid-third of the esophagus.
- Adenocarcinoma is usually found in the lower third of the esophagus near the gastric opening.
- Location:
Microscopic pathology
Nuclear atypia of malignancy:
- Found in both types:
Squamous cell carcinoma:
- Atypical squamous cells invade the basement membrane [9]
- Cytology of squamous cells:
- Eccentric nucleus
- High mitotic activity
- Eosinophilic cytoplasm
- Squamous whorls or keratin pearls
- Cytology of squamous cells:
Adenocarcinoma
- Atypical adenomatous cells show:
- Invading cell clusters or glands[10]
- Cribriforming
- Desmoplasia
- Invasion into submucosa
References
- ↑ Napier KJ, Scheerer M, Misra S (2014). "Esophageal cancer: A Review of epidemiology, pathogenesis, staging workup and treatment modalities". World J Gastrointest Oncol. 6 (5): 112–20. doi:10.4251/wjgo.v6.i5.112. PMC 4021327. PMID 24834141.
- ↑ Mao WM, Zheng WH, Ling ZQ (2011). "Epidemiologic risk factors for esophageal cancer development". Asian Pac. J. Cancer Prev. 12 (10): 2461–6. PMID 22320939.
- ↑ Tilanus HW (1995). "Changing patterns in the treatment of carcinoma of the esophagus". Scand. J. Gastroenterol. Suppl. 212: 38–42. PMID 8578231.
- ↑ Jankowski JA, Wright NA, Meltzer SJ, Triadafilopoulos G, Geboes K, Casson AG, Kerr D, Young LS (1999). "Molecular evolution of the metaplasia-dysplasia-adenocarcinoma sequence in the esophagus". Am. J. Pathol. 154 (4): 965–73. doi:10.1016/S0002-9440(10)65346-1. PMC 1866556. PMID 10233832.
- ↑ Koppert LB, Wijnhoven BP, van Dekken H, Tilanus HW, Dinjens WN (2005). "The molecular biology of esophageal adenocarcinoma". J Surg Oncol. 92 (3): 169–90. doi:10.1002/jso.20359. PMID 16299787.
- ↑ Ireland AP, Clark GW, DeMeester TR (1997). "Barrett's esophagus. The significance of p53 in clinical practice". Ann. Surg. 225 (1): 17–30. PMC 1190601. PMID 8998117.
- ↑ Nieman KM, Romero IL, Van Houten B, Lengyel E (2013). "Adipose tissue and adipocytes support tumorigenesis and metastasis". Biochim. Biophys. Acta. 1831 (10): 1533–41. doi:10.1016/j.bbalip.2013.02.010. PMC 3742583. PMID 23500888.
- ↑ Sugarbaker, David (2015). Adult chest surgery. New York: McGraw-Hill Education. ISBN 0071781897.
- ↑ "Squamous cell carcinoma of the esophagus".
- ↑ "Esophageal adenocarcinoma".