Esophageal Cancer Overview
The esophagus is a long, hollow tube that runs from the throat down to the stomach. The esophagus uses a motion called peristalsis, or a rhythm of squeezing and contracting in waves, to propel the food we eat and liquids we drink down into the stomach to begin the process of digestion. Think of it like squeezing a tube of toothpaste. The muscle squeezes food and drink down the tube and then into the stomach, where digestion begins. A special ring of muscle towards the lower esophagus also works to keep stomach acid and digestive juices out of the esophagus.
The esophagus is made up of several different layers. The mucosa layer lines the inside of the esophagus and includes the epithelium or the thin innermost lining, the lamina propria, a layer of connective tissue, and the muscularis mucos, a thin layer of muscle. The next layer of the esophagus is known as the submucosa, and it contains most of the organ’s connective tissue as well as blood vessels and nerves. This layer also contains the glands that secrete mucus and help keep the esophagus lubricated. Next is the muscularis propria, which is a thick layer of muscle. This is the layer that contracts to help force food down into the stomach. The last layer is the adventitia.
Understanding the anatomy of the esophagus is important because different types of cancers originate in different layers of the organ. Cancers that can impact the esophagus include:
- Squamous cell carcinoma. Squamous cell carcinoma begins in the cells of the mucosa layer of the esophagus, mainly the epithelium layer. While these cells line the entire esophagus, cancer most commonly forms in the upper to middle portions of the organ, near the neck and chest cavity.
- Adenocarcinoma. This type of cancer begins in the gland cells that create mucus and tends to be found in the lower portion of the esophagus.
- Gastroesophageal junction tumors or GE. These tumors are adenocarcinomas, but they originate in the area where the esophagus joins the stomach. Sometimes lumped in with stomach cancer, these tumors tend to behave more like esophageal cancers and are typically treated in the same manner as esophageal malignancies.
There are other less common forms of esophageal cancers which can include:
- Lymphoma
- Melanoma
- Sarcoma
The American Cancer Society estimates that in 2021, 19,260 new cases of esophageal cancer cases will be diagnosed in the United States. The majority of those cases will be diagnosed in men as opposed to women. Esophageal cancer cases make up about one percent of all new cancer cases diagnosed in the country.
Symptoms of Esophageal Cancer
It is not unusual for esophageal cancers to present few or no symptoms in the early stages of the development of the disease. That can make detecting cancer early a challenge. Esophageal cancer is also difficult to detect because there are no annual screening recommendations for the disease because the condition tends to be on the rare side. Cancer typically isn’t caught until the growth gets to the point where it begins to impact swallowing or other body systems.
Some of the most common signs and symptoms of the condition, especially in later stages of the disease can include:
- Trouble swallowing
- Chronic cough
- Hoarseness
- Weight loss
- Chest pain
- Vomiting
- Indigestion or heartburn that gets worse
- Blood in the esophagus
It can be hard to detect blood in the esophagus. However, other symptoms in combination with blood in vomit or dark looking or black stool may be indications that the esophagus or another organ is bleeding.
Cause of Esophageal Cancer
Cancer is the result of the uncontrolled growth of cells in the body. The trigger for these cells to grow unchecked is typically linked to a gene mutation, either inherited or generated by environmental or acquired effects. While scientists have identified risk factors for developing the disease, there is still no clear indication of what causes the condition.
Those with a family history of esophageal cancer and other conditions seem to be at a higher risk of developing the disease. Genetic conditions which may contribute to causing the disease and elevate an individual’s risk of developing esophageal cancer include:
- Barrett’s Esophagus
- Tylosis or Howel-Evans syndrome
- Bloom syndrome
- Fanconi anemia
For those with inherited conditions such as Barrett’s esophagus, your doctor may recommend regular screenings that include an upper endoscopy. This test requires that a thin and flexible camera be run down through the length of the esophagus to check for lesions and abnormalities. The physician may also want to remove small samples of tissue from the esophagus during the procedure in order to test for pre-cancerous cells.
Esophageal Cancer Risk Factors
Some risk factors for esophageal cancer can be controlled, while others like age and gender cannot. Several environmental and lifestyle choices can impact a person’s risk of developing esophageal cancer. Other risk factors that may elevate a person’s risk of developing the disease include having a condition that inflicts chronic inflammation and irritation on the esophagus.
Esophageal cancer risk factors may include:
- Age
- Being male
- Certain genetic conditions
- Tobacco use
- Alcohol use
- Inactivity or sedentary lifestyle
- Obesity
- Eating a diet low in fruits and vegetables
- Frequently drinking extremely hot liquids (Temperatures of 149 degrees and hotter)
- Gastroesophageal reflux disease or GERD
- Human papillomavirus infection
Survival Rates
The problem with esophageal cancer is that it is hard to detect early because disruptive symptoms don’t tend to manifest until the later stages of the disease. The relative five-year survival rate for patients diagnosed with esophageal cancer is just under 20 percent, according to the National Cancer Institute. If the disease is caught early and the growth is localized to the primary site of infection, the five-year survival rate is 46 percent. Unfortunately, once cancer has metastasized or spread from the esophagus, the five-year survival rate drops to five percent.