- Clinical science
Esophageal cancer typically assumes the form of adenocarcinoma or squamous cell carcinoma, although there are some rarer tumors. Adenocarcinomas are considered the fastest-growing neoplasia in Western countries, while squamous cell carcinoma is still most common in the developing world. Adenocarcinoma, which usually affects the lower third of the esophagus, may be preceded by Barrett's esophagus, a complication of gastroesophageal reflux disease (GERD). In addition to GERD, other risk factors include obesity and smoking. Squamous cell carcinomas mostly occur in the upper two-thirds of the esophagus. Known risk factors for squamous cell carcinoma include carcinogen exposure from alcohol and tobacco consumption, and dietary factors (e.g., diet low in fruits and vegetables). Esophageal cancers are often asymptomatic in early stages of the disease. Locally advanced disease is common at presentation, progressive dysphagia being the primary symptom. Hoarseness, weight loss, and hematemesis may also be present. Endoscopy is the primary diagnostic test, enabling direct visualization and biopsy of the lesion for histopathological confirmation. Curative surgical resection may be considered for locally invasive cancers. Esophageal cancer is unresectable at presentation in about 60% of patients. Chemotherapy, radiation, and palliative stenting play a role in the management of unresectable disease.
- Sex: ♂ > ♀ (3:1)
- Peak incidence: 60–70 years of age
- Adenocarcinoma: most common type of esophageal cancer in the US 
- Squamous cell carcinoma (SCC): most common type of esophageal cancer worldwide 
Adenocarcinoma is more common in the US of America.
Epidemiological data refers to the US, unless otherwise specified.
- Risk factors
- Localization: mostly in the lower third of the esophagus
Squamous cell carcinoma (SCC)
- Risk factors 
- Localization: mostly in the upper two-thirds of the esophagus
The primary risk factors for squamous cell esophageal cancer are alcohol consumption, smoking, and dietary factors (e.g., diet low in fruits and vegetables)!
- Early stages: Often asymptomatic but may present with swallowing difficulties or retrosternal discomfort
- Late stages
Esophageal cancer is a "silent" disease and typically becomes symptomatic at advanced stages!
Esophagogastroduodenoscopy (best initial and confirmatory test) 
- Direct visualization of the tumor
- With biopsy of any suspicious lesions
- Barium swallow: asymmetrical and irregular borders of the esophagus with characteristic stenosis and proximal dilatation (apple core lesion)
- Transesophageal endoscopic ultrasound
- Chest and abdominal CT; and/or PET
- Bronchoscopy or laparoscopy
- Histological characteristics: often present with adjacent Barrett mucosa; (columnar epithelium with goblet cells) and high-grade dysplasia
- Histological characteristics
- Locally invasive disease that has not invaded surrounding structures
- High-grade metaplasia in
- For downstaging → potentially allows for later resection
- As definitive treatment in patients with proven complete response (e.g., during endoscopy)
- Surgical resection
- Neoadjuvant chemoradiation
- Indication: patients with advanced disease (majority of patients)
- Stent placement
- Other endoscopic treatments (e.g., laser therapy)
- Generally poor prognosis due to an aggressive course (due to an absent serosa in the esophageal wall) and typically late diagnosis 
- The more distal the tumor, the better the prognosis