Cancer that originates in the esophagus is called esophageal carcinoma. This type of cancer typically develops in the mucosal surface of the esophagus and invades tissues beneath this surface as it spreads. Esophageal carcinoma is the world's seventh-leading cause of deaths from cancer. The highest rates of this cancer occur in parts of Russia, China and Iran.
The two most common types of esophageal carcinoma are esophageal squamous carcinoma and esophageal adenocarcinoma. Although both of these originate in the esophagus, they develop in different cell types and as a result of different pathological processes. Esophageal squamous carcinoma is more common in people who smoke and drink alcohol heavily, whereas esophageal adenocarcinoma is linked to gastroesophageal reflux disease.
Both of these causes are linked to the presence of toxic substances in the esophagus: nicotine and alcohol in the case of squamous carcinoma and gastric acid in the case of adenocarcinoma. Over time, exposure to these toxic, irritating substances causes inflammation of the esophagus. Inflammation eventually results in cellular changes that can lead to cancer. Contributing factors that can increase the risk of esophageal cancers include obesity, nutritional deficiency and human papillomavirus infection.
Symptoms of esophageal carcinoma include difficulty swallowing solids and liquids, pain when swallowing, weight loss, hoarseness, persistent coughing and respiratory problems. The presence of hoarseness, coughing and respiratory symptoms sometimes indicates that the cancer has advanced too far to respond well to surgery. Swollen lymph nodes in the neck or beneath the clavicles can be a sign of metastasis. When metastasis occurs the most common targets are the lungs and liver.
Treatment options for these cancers include chemotherapy, radiation therapy, laser therapy, photodynamic therapy and surgery. In most cases, patients will undergo at least two types of treatment. For example, surgery to remove the bulk of tumors is often followed by chemotherapy to kill any remaining cancer cells. Using multiple treatments reduces the risk of metastasis and the recurrence of cancer.
Esophageal carcinomas often are diagnosed late in the progression of the disease, which contributes to an overall poor prognosis. Treatments are exhausting, and patients with advanced disease are often malnourished because of an inability to eat. The five-year survival rate for esophageal carcinoma is approximately 15 percent. This figure varies according to the stage at which people receive treatment and the type of treatment they receive. When surgical removal is combined with pre-surgery radiation therapy and post-surgery chemotherapy, the five-year survival rate can increase to almost 50 percent.