The esophagus is a tube that connects your throat to your stomach and helps all the food and drinks you consume pass through it to reach the stomach. Approximately 25 cm long, it is an essential part of your digestive system and part of the gastrointestinal (GI) tract.
The esophagus is a combination of skeletal and partly smooth muscles, with the top 2-4 cm being entirely skeletal, the middle skeletal and smooth muscle (Figure 9), and the end portion, the last 11 cm or so comprising smooth muscles.
Esophageal cancer, also called esophagus cancer, is born in the oesophagus cells. When these cells multiply out of control and form a tissue mass called a tumor, it can be malignant. Esophagus cancer starts in the inner layer of the esophageal wall and pushes outward.
A characteristic of most oesophagal cancers is they are classified based on the type in which they originate. Their growth is particular to each kind of cell, and treatment calls for approaches specific to the patient.
Esophageal cancer can occur in any part of the organ, with men being more susceptible.
The main types of esophageal cancer are:
This esophageal cancer is the most prevalent. It begins in the gland's cells situated at the esophagus’s bottom. These glands are essential structures within the esophagus and secrete substances into the digestive tract to perform essential functions like protecting the organ from the acids secreted during digestion.
Cancer of the cells in these glands is known as adenocarcinoma. People suffering from chronic acid reflux, gastroesophageal reflux disease (GERD), Barrett's esophagus and chronic heartburn have higher chances of developing adenocarcinoma.
Adenocarcinoma typically occurs in the lower portions of the esophagus or the stomach's upper part.
It starts in squamous cells in the inner lining of the esophagus called the mucosa. Squamous cells are thin, flat cells that appear like fish scales under a microscope. Squamous cell carcinoma is a common malignancy in the organ's upper and middle portions.
is an extremely rare form of cancer, and research is still on to get more clarity. The tumors are larger and occur in the lower and middle third of the esophagus, and small Cell Carcinoma is considered an aggressive form of cancer.
Cells subjected to chronic stress can change their behavior resulting in tumors. Many lifestyle habits cause this stress promoting the growth of cancer:
Smoking: Tobacco use is a known cause of cancer, and cigarette smoke can aggravate the lining of organs, including the esophagus.
Heavy drinking: People who drink excessive amounts of alcohol are at risk of developing many health problems, including cancer of organs such as the liver and esophagus. Remember, everything you eat and drink passes through the esophagus.
Heartburn: It is a condition where the stomach acid travels back into the esophagus because the sphincter muscle at the end of the food pipe does not close properly. It creates a sensation of discomfort in the stomach and chest region called heartburn or acid reflux.
Gastroesophageal reflux disease (GERD): When a person experiences chronic acid reflux, it leads to a condition called Gastroesophageal reflux disease (GERD).
Barrett's esophagus: In people with prolonged GERD, the esophageal tissue is injured due to the constant acid presence. It thickens or hardens the esophageal walls, leading to a condition called Barret's esophagus. It increases the risk of random cell multiplication due to the stress on the cells.
Achalasia: In this condition, esophageal nerves get damaged, which makes them unable to push the food down to the stomach. The food remains in the food pipe, undergoing chemical changes due to the acids and going back into the mouth, causing extreme discomfort.
Bile reflux: Bile, a liquid produced by the liver to aid digestion, can back up in the stomach and reverse into the esophagus.
Drinking scalding liquids: It can irritate the esophageal lining.
Lack of fiber-rich foods in the diet: Eating processed foods increases stress on the Gastrointestinal Tract (GI) due to poor movement of food through the esophagus.
Radiation treatment for chest or upper abdomen: When the esophagus cells are exposed to radiation from nearby organs, it can increase cancer risk.
Change in stool color: Bleeding from the esophagus due to cancer can turn stools into a dark, almost black shade.
The trouble with swallowing: It is among the most common symptoms. It induces a feeling of food stuck in the chest, leading to choking episodes. If neglected, the symptoms worsen, with increasing pain during swallowing. Even swallowing liquids can become a challenge as cancer grows. Seek immediate diagnosis if you are having trouble eating and are resorting to liquid or pulpy foods that make swallowing easier.
Excessive production of saliva: The mouth produces excess saliva due to difficulty swallowing.
Chronic chest pain: A constant heartburn or food reflux creating a burning sensation in your chest is a potential symptom of esophageal cancer because it may irritate the tumor in the esophagus.
Unintentional weight loss is a consequence of esophageal cancer due to many factors, including reduced food intake, difficulty swallowing or diminished hunger.
Persistent cough and hoarse voice: A stubborn cough is an alarm bell linked to esophageal cancer. It may or may not occur while eating food.
Mapping the stages of cancer reveals its spread and severity and helps doctors determine the treatment protocol. Like all cancers, esophageal or esophagus cancer also has stages of development.
Doctors use a TNM system to chart its course based on the following factors:
o How large is the tumor (T)?
o Has it spread outside the esophagus affecting the nearby lymph nodes (N)?
o Has it metastasized (spread to other body parts) (M)?
Doctors also check which section of the esophagus is cancerous and how deep it has gone into the layers of its lining and wall. There are four layers of the esophageal wall: the inner layer or mucosa, the second layer or submucosa, the third layer or muscularis propria and the outermost layer or adventitia.
The cancer grade is a critical determinant of how much the cancer cells resemble normal cells.
The grade provides clues to how cancer might progress.
Grade 1: (It's a low-grade rating, where the cancer cells look almost like normal cells.
Grade 2: The cells resemble normal cells a little.
Grade 3: The cancer cells look abnormal.
Stage 0
Abnormal cell growth in the lining may turn cancerous.
Stage I: It has two categories, A and B. A is low-grade cancer in the inner layer or mucosa with no spreading, and stage B is higher-grade or low-grade cancer spreading to the second, submucosa, or third layer but not to the nearby lymph nodes.
Stage II has various grades of malignancy, either localized in one of the oesophagus layers, with tumors and spreading to nearby lymph nodes.
Stage III: In this stage, the cancer is prevalent in any of the four layers of the esophagus, spreading to other areas, including no more than two lymph nodes, around the heart, etc.
Stage IV has a more widespread malignancy, with cancer attacking more lymph nodes and spreading outside the esophagus.
Stage 0: Abnormal cell growth in the outermost lining may turn cancerous.
Stage I: This stage has three levels low-grade cancer in the innermost layer that is localized, existing in the innermost and second layer but localized, or also in the third esophageal layer but localized.
Stage II: It denotes cancer that is higher-grade, growing into the third esophageal layer but localized, spreading to the fourth or outermost layer, and localized or spreading only to the nearby lymph nodes.
Stage III: Cancer growing in the innermost or second layer and to a few lymph nodes, spreads to the third layer and attacks one or two lymph nodes or to the outermost layer and spreaspreads lymph nodes and other nearby organs such as the muscle that separates chest and stomach.
Stage IV: Cancer has spread to areas such as the diaphragm, heart sac and adjacent lymph nodes and organs rather than the esophagus.
There are several ways in which esophageal cancer is diagnosed.
Physical check-up and medical history: Doctors check for symptoms, conduct a physical examination, ask for the patient's medical history, and suggest various tests.
Imaging tests: Various imaging procedures such as X-rays, magnetic fields, sound waves, or radioactive tests are done to take pictures of the internal body to detect signs of cancer and its spread.
Barium test: Due to the difficulty in swallowing, which is often a symptom of esophageal cancer, doctors recommend a barium test where the patient drinks a chalky liquid called barium that lines the esophageal wall. An X-ray shows the barium path line in the esophagus to reveal abnormalities. A barium test is effective in catching the early onset of cancer.
Computed tomography (CT): A CT scan is an X-ray that takes multiple and sectional images of the esophagus, which are joined to create a composite picture. It reveals the presence of cancer and its path. The patient is typically given an oral contrast liquid highlighting the esophagus and intestinal tract.
CT-guided needle biopsy: A CT scan can direct a biopsy needle to the suspected area to obtain a tissue sample.
Magnetic Resonance Imaging (MRI), PET (Positron emission tomography): MRI scans use radio waves and strong magnets to look for cancerous cells. A PET scan uses a radioactive method to detect cancerous cells and growth; sometimes, doctors recommend PET and CT scans.
Upper endoscopy: A flexible, narrow tube attached to a tiny video camera is guided into the esophagus to check for cancerous signs. Sometimes, a thin, hollow needle is inserted into the endoscope that collects a small tissue sample from the esophagus for a biopsy. Upper endoscopy is used to assess if surgery can excise the tumor.
Endoscopic ultrasound: The endoscope uses sound waves to get close to cancerous growths in the esophagus and gauge their severity and spread. It helps doctors know of enlarged lymph nodes.
Bronchoscopy: It detects cancer in the upper area of the esophagus and charts its path.
Thoracoscopy and laparoscopy: A lightweight hollow tube is guided into the body through a minor incision under general anesthesia to obtain oesophagal tissue samples for a biopsy.
Lab tests: Usually, it is biopsied if a suspected esophageal cancer is found on endoscopy or an imaging test. In a biopsy, the doctor removes a small piece of tissue with a cutting instrument passed through the scope.
HER2 testing: If esophageal cancer is too advanced for surgery, biopsy samples may be tested for the HER2 gene or protein. Excess amounts of this protein help cancerous cells grow. Drugs targeting the protein may help treat advanced cancer along with chemotherapy, and this treatment is effective only in cases producing excessive HER2 genes or proteins.
PD-L1 testing: It is a test to see if a certain kind of protein called PD-L1 is being made in cases of esophageal cancer that will not respond to surgery. Tumors that produce this protein are treated with immunotherapy drugs.
Depending on the degree of cancer, several treatments are used to combat esophageal cancer.
Surgery: If cancer has damaged the esophageal tissue beyond repair, the section of the esophagus most damaged is surgically removed to stop the spread of the tumour. The procedure is called esophagectomy. The stomach is then pulled up to join the remaining healthy part of the esophagus to enable normal digestive processes to continue.
Doctors can use a plastic tube or a section of the intestine to bridge the gap. If there is a tumor blocking the esophageal tube, a stent may be used to open up the passage.
Lymph node surgery: If the lymph nodes near the esophagus are affected, they may be surgically removed.
Radiation therapy: Two kinds of radiation therapies, Internal and External, are used to treat esophageal cancer. Internal radiation uses needles or wires containing radioactive inserted into the organ to kill the cancer cells, and external radiation targets the cancerous area from outside the body.
Chemotherapy: This procedure uses drugs to thwart cancer cell growth which can be taken orally or injected. When the drugs reach all areas of the internal body to target cancer cells, it is called systemic chemotherapy, and on targeted areas, it is known as regional chemotherapy. Chemotherapy is delivered based on the spread and stage of cancer.
Chemoradiation: It is a combination of chemo and radiation.
Laser: This treatment uses narrow bands of intense light to kill cancer cells.
Electrocoagulation: Batches of electric current are passed through the cancerous areas to kill the malignant cells.
Immunotherapy: The cancer patient's immune system is made to fight the disease through various advanced methods in cases where surgery or excision of the affected organ is not an option. Specifically, one approach is to help the T cells, a category of immune cells, overcome the ability of cancer cells to trick the immune system and destroy them.
There are three stages doctors consider for treatment:
Pathological stage: In this method, post-surgery, the tissue removed from the esophagus is examined for further procedures. At this point, the results of the Clinical and pathological stages are often considered together.
