Esophageal cancer is a type of malignant disease in which the uncontrollable growth of cells occurs in the tissues present in the esophagus. Esophageal cancer is a disease in transition to epidemiology. The cells in nearly any region of the body can take the form of cancer and can proliferate to other regions of the body. Esophageal cancer results when abnormal cells grow out of control in esophageal tissue. Eventually, the cells grow into a mass called a tumor.
The esophageal wall has various layers:
- Mucosa: Mucosa is a layer that lines the esophageal region’s inside. It has the following three portions:
The epithelium is said to be the innermost esophageal lining and normally comprises flat, thin cells known as the squamous cells. This is the portion where most cancers related to the esophagus start.
The lamina propria is a layer of connective tissue that is thin and it is right under the epithelium.
The muscularis mucosa is a layer of muscle that is also very thin and is present under the lamina propria.
- Submucosa: This layer of connective tissue just below the mucosa contains blood vessels and nerves. In some parts of the esophagus, this layer also includes glands that secrete mucus.
- Muscularis propria: This is the layer of muscle that is thick and is present under the submucosa. Its contraction occurs in a coordinated manner in order to push food downwards to the esophagus from the throat towards the stomach region.
- Adventitia: This layer of the esophagus is the outermost layer, and is made by connective tissue.
Esophageal cancer can grow anywhere along the whole length of the esophagus. It first grows in the inner layer of the esophagus wall and grows through the other layers in the outward direction. The structure of the esophagus can be described as the hollow, muscular passageway that moves food as well as liquid starting from the throat to the stomach. The wall of the esophagus is made up of several coverings of tissue, which include the mucous membrane, connective tissue, and muscle.
At the upper esophageal opening, there is a particular ring of muscle (which is known as the upper esophageal sphincter) that functions in relaxation in order to extend the esophagus when it feels the food or liquid coming toward it. When you swallow, food and liquids travel through the inside of the esophagus (called the lumen) to reach the stomach. The lower esophageal region which makes contact with the stomach region is called the Gastroesophageal (GE) junction. A particular ring of muscle near the gastroesophageal junction, known as the lower esophageal sphincter, is used to control the motion of food from the esophageal region into the stomach region.
The cancers which begin in the oesophageal area are much more common in the population of males than in females. The estimates of the American Cancer Society for esophageal cancer in the United States for the year 2022 are as follows:
- About 20,640 new cases of esophageal cancer were diagnosed (16,510 in males and 4,130 in females)
- About 16,410 deaths from esophageal cancer (13,250 in males and 3,160 in females)
The sixth most common cause of cancer deaths in the whole world is Esophageal cancer. There is variance in the rates of incidence within different geographic locations.