Cervical cancer is the name for cancers that form in the cervix, the lower part of the uterus where it meets the vagina. Most cases arise from human papillomavirus infection. Abnormal cells can form a tumour and spread to other parts of the body.…
What is esophageal cancer?
Esophageal cancer occurs when abnormal cells grow uncontrollably in the esophagus. The esophagus is part of the digestive system and is the muscular tube that connects the mouth to the stomach.
Esophageal cancer is a relatively rare cancer that is usually detected at an advanced stage when outcomes are less positive. The American Cancer Society's estimates for esophageal cancer in the United States for 2018 are about 17,290 new esophageal cancer cases diagnosed (13,480 in men and 3,810 in women) and about 15,850 deaths from esophageal cancer (12,850 in men and 3,000 in women).
The cause of esophageal cancer, as with other cancers, is damage to cellular DNA. This results in uncontrolled growth of damaged cells, which leads to the formation of a cancer. The cancer can invade nearby tissues, or spread via the bloodstream or lymphatic system to other areas of the body.
The exact cause of esophageal cancers is not well known. However, certain risk factors are known to increase the risk of developing this condition.
Risk factors for esophageal cancer include:
- Tobacco and alcohol consumption - smoking and alcohol consumption both significantly increase your risk of developing esophageal cancer. Consumed together, the risk is magnified many times over;
- Barrett's esophagus - Barrett's esophagus occurs when recurring acid reflux from the stomach (heartburn) causes cells in the esophagus to change from squamous cells to columnar cells. This change of cell type is called metaplasia. This condition can be a precursor of a cancer originating in glandular cells (adenocarcinoma);
- Obesity - obesity, particularly when fat is mainly in the abdominal area, increases your risk of developing adenocarcinoma, and;
- Nitrosamines - nitrosamines are carcinogens present in foods such as salted vegetables and preserved fish that have been linked to squamous cell carcinoma of the esophagus.
Esophageal cancer can occur in different types of cells in the esophagus.
Squamous cell carcinoma
Squamous cell carcinoma of the esophagus originates in the squamous cells in the lining of the esophagus (mucosa). It tends to occur in the upper esophagus. Smoking and alcohol are common risk factors for squamous cell carcinomas.
Adenocarcinoma of the esophagus originates in the glandular cells of the submucosa (the supportive layer of tissue) of the esophagus. It tends to occur in the lower esophagus. Barrett's esophagus is a known risk factor for adenocarcinomas.
Globally, squamous cell carcinoma is the most common type of esophageal cancer, whereas in developed countries adenocarcinoma is more common.
Less common cancers
Stages of esophageal cancer
Treatment outcomes can vary greatly depending on the stage of cancer. Cancer is staged according to the size and location of the primary tumor and whether it has spread to lymph nodes or other organs in the body.
Carcinoma in situ (Tis) is when the cancer is only in the upper layer lining the esophagus, known as the mucosa.
Stage IA - The cancer hasn't grown beyond the supportive layer of tissue called the submucosa of the esophageal wall (T1).
Stage IB - The cancer has spread into, but not beyond, the muscular layer of esophageal wall, called the muscularis propria (T2).
Stage IIA - The cancer has spread into the membrane that covers the outside of the esophagus, but not to nearby lymph nodes (T3).
Stage IIB - The cancer has spread to 1-2 nearby lymph nodes, but hasn't grown beyond the muscle layer (T2, N1).
Stage IIIA - The cancer has grown into adjacent structures like the diaphragm, lining of the lungs or heart, but not elsewhere (T4); or the cancer has grown into the membrane covering the esophagus and has also spread to 1-2 nearby lymph nodes (T3, N1); or the cancer has not grown further than the muscle layer, but has spread to 3-6 nearby lymph nodes (T2, N2).
Stage IIIB - The cancer has grown into the membrane that covers the esophagus and has also spread to 3-6 lymph nodes, but not elsewhere (T3, N2).
Stage IIIC - The cancer has grown into adjacent structures like the diaphragm, lining of lung or heart, windpipe, spine, or major blood vessels, and has spread to any nearby lymph nodes (T4); or the cancer has spread to 7 (or more) nearby lymph nodes, but hasn't spread elsewhere (N3).
The cancer has spread throughout the body to distant organs, such as the lungs and liver (T4).
Signs and symptoms
Signs and symptoms of esophageal cancer may include:
- Difficulty swallowing;
- A hoarse voice;
- Nausea and vomiting, which may contain blood;
- Pain in the chest, throat or between the shoulders;
- Weight loss, which may occur because you're having difficulty swallowing and are put off eating, but it can also be a sign of advanced cancer, and;
- Acid reflux - it is important to know, however, that reflux is a common condition even in the absence of cancer.
Methods for diagnosis
If you have signs and symptoms that might indicate esophageal cancer, a gastroscopy will generally be the first method of investigation (see below). A biopsy of any suspicious area of the esophagus can also be taken. The tissue from the biopsy can then be examined by a pathologist to see if there are any features of a cancer. If a cancer is confirmed, a variety of further investigations may be performed to assess the extent of the cancer, including imaging or other procedures.
Computerized tomography scan
A computerized tomography (CT) scan uses X-rays to develop a 3D image of the body. This can detect smaller tumors more effectively than a simple X-ray can. The scan may be used to assess the size or spread of a tumor and may show enlarged lymph nodes or an effect on other organs such as the liver.
Magnetic resonance imaging
Magnetic resonance imaging (MRI) is similar to a CT scan, but it uses magnetism instead of X-rays for imaging.
Positron emission tomography
Positron emission tomography (PET) requires that an injection with a radioactive label, or tracer, first be administered. When combined with a CT scan, it produces images that can provide the doctor with additional characteristics about the tumor.
A gastroscopy is performed by inserting a thin tube with an attached camera through your mouth into the esophagus. Sometimes an ultrasound can be performed at the same time to produce images of the wall of the esophagus and internal organs near it. Cells or a tissue biopsy can be obtained from the area using the gastroscopy procedure to then be analyzed.
During a laparoscopy, your internal abdominal and pelvic cavities will be checked for abnormalities using a slender camera inserted through a small incision in your abdomen. A biopsy can be taken during the procedure.
A biopsy is a removal of a tissue sample for examination under a microscope. The biopsy is the only definite way of making a cancer diagnosis, as it provides the most accurate analysis of the abnormal-looking cells.
Types of treatment
Depending on the size and location of the cancer, surgery can be performed in a number of ways. Surgical options are often complex and extensive, however, they can offer the possibility of a cure. Your surgeon can help discuss these options with you.
Adjuvant therapy is given after surgery, with the aim of preventing the cancer from returning. It can take the form of radiotherapy and/or chemotherapy (see below).
Like adjuvant therapy, neoadjuvant therapy also uses radiotherapy and/or chemotherapy, but is provided before surgery.
Chemotherapy works by attacking cancer cells and stopping their reproduction. Various medications are used, which are generally administered intravenously. They are often given in cycles, followed by rest periods, which help to reduce the toxic side effects of chemotherapy. Your doctor will monitor your dosage and treatment schedule to ensure optimal therapeutic dosage is administered, with minimum side effects.
In this type of therapy, focused X-rays from an external beam radiation source are applied to the area where the cancer was located. Radiotherapy helps to reduce the recurrence of cancers at their original site.
Immunotherapy, also known as biologic therapy, is used for some types of cancer. It involves the use of medications that trigger the immune system to help fight the cancer. In the case of esophageal cancer a monoclonal antibody drug, called trastuzumab, can be used for particular types of adenocarcinoma, specifically the HER2-positive tumors. However, trastuzumab cannot be combined with a chemotherapy drug called antracycline, as the combination increases the risk of heart problems.
Some people diagnosed with cancer seek out complementary and alternative therapies. None of these alternative therapies are known to cure cancer, but some can help people feel better when used together with conventional medical treatment. It is important to discuss any treatments with your doctor before starting them.
Treatment side effects
Side effects from cancer treatment can include the following:
- Nausea, vomiting and fatigue - these can result from chemotherapy and radiotherapy. Whether or not the treatment makes you feel sick is not an indication of how well the treatment is working;
- Altered bowel habits - constipation frequently occurs during chemotherapy, probably as a result of anti-nausea and some pain-relief medication. Radiotherapy may cause diarrhea;
- Difficulty swallowing - radiotherapy can cause a sore throat and difficulty swallowing. Occasionally ulcers can develop and you need to have a liquid or soft diet for some time;
- Heart problems - chemotherapy, radiotherapy and immunotherapy can potentially cause heart failure and other heart conditions;
- Respiratory failure - reduced respiratory function and abnormal function of the diaphragm can result from tissue damage in the chest (thoracic) cavity following surgery. Other lung complications, especially in the immediate days following surgery, include pneumonia and pneumothorax (collapsed lung).
- Joint and muscle pain - this can occur after a treatment session and can last a few days;
- Temporary hair loss from the head and body due to some types of chemotherapy. It will grow back after treatment has ended, and;
- Tingling in the hands and feet - some chemotherapeutic agents can affect the nerves. It is important to tell your doctor if you develop these symptoms.
Advanced esophageal cancer
Advanced esophageal cancer can metastasize. This is when the cancer spreads to other parts of the body through the bloodstream and lymphatic system. This can interfere with the vital function of the affected organ or body part.
The prognosis for esophageal cancer depends on the type and stage of the disease, but the overall five-year survival rate from the point of diagnosis is 16%. For those who survive the first year, this increases to 35% and for those who survive the first five years, the forward five-year survival rate further increases to 78%. 
It is important to remember survival rates are only an indication and are based upon the averages of previously treated patients. It is not an absolute prognosis for an individual. It is often difficult to accurately predict an individual's cure or survival rate. Constant advances in treatment are continually improving these statistics.