Esophagus

What is esophageal cancer

Esophageal cancer occurs when the cells of the lining of the esophagus (the tube that connects the throat to the stomach) begin to grow uncontrollably. It typically starts anywhere along the inner layer of the organ’s wall and grows outward through the other layers. The most common type of esophageal cancer today is adenocarcinoma, with a growing number of new cases, followed by squamous cell carcinoma.

In Brazil, esophageal cancer is the sixth most common cancer among men and the 15th among women (in both cases, excluding non-melanoma skin cancer). It is the eighth most common in the world, and its incidence in men is about twice as high as in women.

Types of esophageal cancer

There are two main types of esophageal cancer, based on the type of cell where it begins:

• Squamous cell carcinoma – the inner layer of the esophagus (mucosa) is lined with squamous cells. Cancer that begins in these cells is called squamous cell carcinoma. It can occur anywhere along the esophagus, but is more common in the neck region (cervical esophagus) and in the upper two-thirds of the chest cavity (upper and middle thoracic esophagus); and
• Adenocarcinoma – Cancers that begin in glandular cells (cells that produce mucus) are called adenocarcinomas. They are often found in the lower third of the esophagus (lower thoracic esophagus).

Other types of cancer can also occur in the esophagus, including lymphomas, melanomas, and sarcomas. However, these cancers are very rare.

Symptoms of esophageal cancer

Most esophageal cancers do not cause symptoms in the early stages, and the diagnosis in asymptomatic individuals is rare and usually accidental.

Common symptoms of esophageal cancer include:

• Difficulty swallowing – it is the most common symptom of esophageal cancer. Dysphagia (the sensation that food is stuck in the throat or chest) is usually a symptom caused by a cancer that obstructs the passage of food and liquids. When swallowing becomes difficult, people often change their diet and eating habits without realizing it, eating small portions and chewing food slowly;
• Chest pain – some people describe a feeling of pressure or burning in the chest. These symptoms are often caused by other problems, such as heartburn, and are rarely seen as a sign that a person may have cancer; and
• Weight loss – many people with esophageal cancer lose weight without apparent cause, diet, or other diseases to justify it. Swallowing problems, reduced appetite, and an increase in the body’s own cancer metabolism are the causes. Weight loss can reach up to 10% or more of body weight.

Other possible symptoms of esophageal cancer may include:

• Hoarseness;
• Persistent cough;
• Vomiting; and
• Digestive bleeding.

It’s important to note that having one or some of these symptoms does not mean that a person has esophageal cancer. The key, especially when there is abnormal difficulty swallowing, is to seek medical evaluation.

Diagnosis of esophageal cancer

When faced with a set of symptoms, the first test to confirm a suspicion of esophageal cancer is upper gastrointestinal endoscopy (UGIE) with biopsy. After the diagnosis is confirmed, imaging tests should be performed for staging, which will guide the best strategy to combat the disease. The most common ones are:

• Endoscopy – a procedure performed with the patient sedated, in which an endoscope with a camera evaluates the walls of the esophagus. During endoscopy, samples of identified lesions are taken.
• Endoscopic ultrasound – a probe that emits sound waves is placed at the end of an endoscope. This test is done simultaneously with upper gastrointestinal endoscopy and is useful for determining the size of an esophageal cancer and how much it has grown into nearby areas. It also helps to show if lymph nodes have been affected by cancer.
• Bronchoscopy – may be done for cancers that are located in the upper part of the esophagus. The purpose is to see if it is close to the trachea or bronchi (tubes that carry air from the trachea to the lungs).
• Thoracoscopy and laparoscopy – are exams that allow the doctor to see the lymph nodes and other organs near the esophagus inside the chest (via thoracoscopy) or in the abdomen (via laparoscopy) through a camera. They can also be used to obtain biopsy samples. These exams are performed with the patient under anesthesia; and
• Computed tomography (CT) – Chest, abdomen, and pelvis CT plays a crucial role in detecting metastatic lymph nodes, hematogenous metastases, and also in evaluating the degree of local tumor involvement.

A biopsy should also be performed, in which the doctor removes a small piece of tissue with an instrument passed through the endoscopy. It is through this procedure that the diagnosis of esophageal cancer can be confirmed, and it is also important for researching molecular alterations that may contribute to choosing the best treatment.

Treatment for esophageal cancer

Treatment for esophageal cancer can be done with surgery, radiation therapy, and chemotherapy, either alone or in combination, according to the stage of the disease and the patient’s clinical conditions.

For some early-stage cancers, surgery may be used to try to remove the cancer and part of the surrounding normal tissue. It can be combined with other treatments, such as chemotherapy and/or radiation therapy.

Esophagectomy is a surgical procedure performed to remove part or most of the esophagus, and it has the potential to cure the disease. The length of the esophagus to be removed depends on the stage of the tumor and where it is located. During the surgery, nearby lymph nodes are also removed. They are then analyzed in the laboratory to see if they have cancer cells.

Chemotherapy involves administering medications intravenously (injected into the vein) or orally. Alone, chemotherapy rarely cures esophageal cancer – that’s why it’s often given with radiation therapy.

Chemotherapy can be used at different times during the treatment of esophageal cancer. After surgery, and in combination with radiation therapy, the goal is to eliminate any unseen cancer cells. Before surgery, it can reduce the size of the tumor.

In advanced cancers, chemotherapy, being a systemic treatment, can help fight cancer that has spread to other organs.

Prevention of esophageal cancer

The consumption of very hot beverages, such as mate and coffee, above 65°C, increases the risk of developing esophageal cancer. The mechanism that explains the carcinogenicity of these beverages seems to be related to the cellular damage caused by excessive heat.

Alcoholic beverages are also strongly associated with an increased risk of developing the disease. Ethanol is converted in the body into acetaldehyde, a carcinogenic agent for humans.

Main factors associated with esophageal cancer:

• Consumption of very hot beverages, above 65º;
• Alcohol consumption;
• Excess body fat (reflux and metabolic changes caused by weight);
• Smoking;
• Exposure to environments with ionizing radiation (X-ray and Gamma).

There is no scientific evidence that screening for esophageal cancer brings more benefits than risks, and therefore, it is not recommended at this time.