Types of cancer

Esophagus

Esophageal cancer causes no symptoms in its early stages. Difficulty swallowing, weight loss, and chest pain are some of the main symptoms. Consumption of very hot beverages, alcohol and smoking are risk factors.
5 min de leitura
por: Grupo Oncoclínicas
Esophagus
Difficulty swallowing, weight loss, and chest pain are some of the main symptoms of esophageal cancer.

What is esophageal cancer

Esophageal cancer arises when cells in the lining of the esophagus (the tube that connects the throat to the stomach) start to grow out of control. It starts anywhere along the inner layer of the wall of the organ and grows outward through the other layers. The most common type of esophageal cancer today is adenocarcinoma, with an increasing number of new cases, followed by squamous cell carcinoma.

In Brazil, esophageal cancer is the sixth most frequent among men and the 15th among women (in both cases, excluding non-melanoma skin cancer). It is the eighth most frequent 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 in which it starts:

  • Squamous cell carcinoma – the inner layer of the esophagus (mucous membrane) is lined with squamous cells. Cancer that starts in these cells is called squamous cell carcinoma. It can occur anywhere along the esophagus, but is most common in the neck region (cervical esophagus) and the upper two-thirds of the thoracic cavity (upper and middle thoracic esophagus); and
  • Adenocarcinoma – Cancers that start in the gland 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. But these cancers are very rare.

Symptoms of esophageal cancer

Most esophageal cancers cause no symptoms in the early stages, and diagnosis in asymptomatic people is rare and usually accidental.

Common symptoms of esophageal cancer are:

  • Difficulty swallowing – this is the most common symptom of esophageal cancer. Dysphagia (feeling 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 pressing or burning sensation in the chest. These symptoms are often caused by other problems, such as heartburn, and are rarely seen as a sign that the person may have cancer; and
  • Weight loss – many people with esophageal cancer lose weight without apparent cause, diet, or other justifying illnesses. Swallowing problems, reduced appetite, and an increase in the cancer’s own metabolism are the causes. The weight loss can be up to 10 percent or more of body weight.

Other possible symptoms of esophageal cancer may include:

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

It is important to note that having one or more of these symptoms does not mean the patient has esophageal cancer. The important thing, especially when there is abnormal difficulty swallowing, is to see a doctor for evaluation.

Diagnosis of esophageal cancer

When faced with a set of symptoms, the first test to confirm a suspicion of esophageal cancer is an upper digestive endoscopy (EGD) with biopsy. After diagnosis is confirmed, imaging exams must be done, with the purpose of staging, which will guide the best treatment strategy. The most common ones are:

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

A biopsy, in which the doctor removes a small piece of tissue with an instrument passed through endoscopy, must also be performed. It is through this process that esophageal cancer diagnosis can be confirmed, and it is also important to look for molecular alterations that can contribute to therapy choices.

Treatment

Esophageal cancer treatment can be done with surgery, radiotherapy, and chemotherapy, alone or combined, according to tumor stage and patient’s clinical conditions.

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

Esophagectomy is a surgical procedure done to remove part or most of the esophagus, and has the potential to cure the disease. The length of 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.

Radiation therapy, a procedure that uses high-energy rays (such as X-rays) or particles to destroy cancer cells, is often combined with esophageal cancer treatment. It may be used before surgery (and along with chemotherapy, if possible), to try to shrink the cancer and make it easier to remove (neoadjuvant treatment). If it is done after surgery, and in conjunction with chemotherapy, it aims to kill any residual cancer cells.

In chemotherapy, drugs are administered intravenously (injected into veins) or or orally. Chemotherapy alone rarely cures esophageal cancer – so it is often prescribed alongside radiation therapy. Chemotherapy can be used at different times during the treatment of esophageal cancer. After surgery, and combined with radiation therapy, it aims to eliminate any unseen cancer cells. Before surgery, it can reduce the size of the tumor.

In advanced cancers, chemotherapy is a systemic treatment, contributing to the fight against cancer located in other organs.

Prevention

Consumption of very hot drinks, 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 to acetoaldehyde, a carcinogen for humans.

Major factors associated with esophageal cancer:

  • Consumption of very hot drinks, above 65 ºC;
  • Alcohol consumption;
  • Excess body fat (reflux and metabolic alterations 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, at the moment, it is not recommended.

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