Background Flashcards
What are the boundaries of the esophagus that divide it into Cx, upper T, midthoracic, lower T, and abdominal regions?
The esophagus spans from the cricopharyngeus at the cricoid to the esophageal-gastric junction (EGJ). The Cx esophagus spans from hypopharynx to sternal notch (15 to <20 cm from incisors), the upper T from the sternal notch to the azygos vein (20 to <25 cm), the middle T from azygos vein to inf pulmonary vein (25 to <30 cm), the lower T from the inf pulmonary vein to the EGJ (30 to <40 cm), and the abdominal from EGJ to 2 cm below EGJ (40 to 45 cm).
Why is esophageal cancer more prone to locoregional spread than other GI cancers?
The esophagus has an adventitial layer but does not have a serosal layer, thus reducing the resistance against local spread of cancer.
What is the incidence and mortality of esophageal cancer in the United States?
There are ∼17,000 cases diagnosed and ∼16,000 deaths per yr in the United States. Males are more commonly affected than females (3:1).
Is there an association b/t esophageal cancer and HPV infection?
The single largest case-control studies by Cao B et al. showed a risk of HPV 2.7-fold greater in cases of esophageal SCC than in controls. (Carcinogenesis 2005)
What are the risk factors for developing esophageal cancer?
Esophageal SCC risk factors: smoking/alcohol, tylosis, Plummer–Vinson syndrome, Fanconi anemia, Bloom syndrome, caustic injury to the esophagus, Hx of H&N cancer, and achalasia. HPV infection has been associated in ∼20% cases in high-incidence areas (China, Africa, and Japan) but none in low-incidence areas (Europe, United States).
Esophageal adenocarcinoma (adeno) risk factors: obesity/GERD, Barrett esophagus, lack of fruits/vegetables, low-socioeconomic status
What are some protective factors for developing esophageal cancers?
Protective factors for developing esophageal cancer include fruits/vegetables and Helicobacter pylori infection (possible atrophic gastritis).
How do pts with esophageal cancer typically present?
Dysphagia and weight loss (>90%), odynophagia, pain, cough, dyspnea, and hoarseness
What is the pattern of spread of tumors of the esophagus?
Tumors of the esophagus spread locoregionally through the extensive submucosal lymphatic plexus or distantly through hematogenous routes.
What histologies predominate based on the tumor location within the esophagus?
The proximal three-fourths of the esophagus (Cx to midthoracic) are mostly SCCs (∼30%–40%), whereas adeno generally is found in the distal esophagus (∼60%–70%).
What more uncommon histologies are seen for tumors of the esophagus?
Adenocystic, mucoepidermoid, small cell, and sarcomatous (leiomyosarcoma) carcinomas (all typically ≤1% of cases). Extremely rare types are lymphoma, Kaposi sarcoma, and melanoma.
What are the common sites of DM seen for esophageal cancers?
Lung, liver, and bone are the most common sites of DM. (Xi M et al., Radiother Oncol 2017)
What is the most important factor that determines nodal mets and DM?
DOI is the most important factor dictating nodal and distant spread. (Mariette C et al., Cancer 2003)
What is the extent of submucosal spread of Dz seen for esophageal cancers, and does it differ by histology?
Gao XS et al. reported the following for SCC: mean microscopic proximal and distal spread beyond GTV of 10.5 ± 13.5 mm and 10.6 ± 8.5 mm, respectively, with 94% of pts having all tumor contained within a 30-mm margin. For adeno, mean spread of Dz is to 10.3 ± 7.2 mm proximally and 18.3 ± 16.3 mm distally, with a margin of 50 mm required to encompass all tumor in 94% of cases. (IJROBP 2007)