By: Prof. Dr. Seyed Saeid Zamanieh Shahri, MD  and  Prof. Dr. Sonia Sayyedalhosseini, MD

Esophageal Cancer (Part I):

The esophagus is the interface between the mouth and the stomach. This part of the digestive tract, like other parts, can be involved in cancer. 

Anatomy and Physiology: 

One of the most important parts of the digestive system is the esophagus. The digestive system consists of a set of hollow organs that are responsible for transporting food from the mouth to the stomach and finally to the intestines and anus for excretion. In this article, we will examine the function of the esophagus and its role in the digestive process. The received food supplies the body with energy when the digestive system breaks it down into molecules that the body can absorb. When liquids and chewed foods enter the throat through the mouth, the brain begins the process of swallowing. The process of digestion begins with the activity of voluntary nerves; And when liquids or food enters the first part of the esophagus, the involuntary nerves continue the digestion process. Food and liquids that enter the esophagus due to their volume and size cause the esophagus to stretch, which causes the irritation of the smooth muscles of the esophagus wall, which then leads to the irritation of the dense network of nerves inside it. These nerves are the main nerves that initiate the muscle coordination operation called peristalsis.

Peristalsis puts pressure on the muscles of the esophagus from top to bottom, in addition, it pushes and moves food and liquids from the beginning of the esophagus to the stomach. If this process is observed from the outside, it is like a wave flow that is going down the esophagus. In order to keep the movement of food and liquids in the right direction (for example, food does not enter the respiratory tube), the digestive system has special muscles called sphincters. Sphincters act like one-way entrances, in the sense that when food and liquids are passing through the esophagus to the stomach, they are in a resting state and in other words, they expand, and after the food enters Stomach becomes tight and contracted to prevent food from returning to the esophagus (reflux).

Symptoms of esophageal cancer: 

Symptoms of esophageal cancer include difficulty in swallowing, regurgitation of food, heartburn, weight loss, and persistent cough. Less common symptoms such as hiccups, chest pain, or enlarged lymph nodes in the neck may be caused by the spread of cancer. Knowing the symptoms of esophageal cancer is important for early detection and treatment of this condition. 

Common symptoms: In the early stages of esophageal cancer, people may experience several symptoms. Most of the symptoms are caused by the enlargement of the tumor and the narrowing of the esophagus, which makes it difficult to pass food.

Difficulty in swallowing: Difficulty in swallowing (dysphagia) is the most common symptom of esophageal cancer, which is seen in 90-95% of patients with this disease. If the esophagus is narrowed by cancer, food may have difficulty passing through it and entering the stomach. It may feel like the passage of food takes longer than usual and the person feels trapped or choked. The esophagus is often significantly narrowed before other symptoms develop. Difficulty swallowing typically begins with larger pieces of solid food, especially meat, bread, and raw vegetables, but can later include semi-solid foods and eventually liquids.

Painful swallowing: Swallowing can be painful for some people. Pain may be felt for a few moments when food or liquid reaches the tumor or due to inability to pass. Also, if the cancer has caused an open wound in the inner wall of the esophagus or has invaded the surrounding tissues, it can lead to pain. Pain during swallowing may be felt between the shoulder blades in the back or in the chest. 

Regurgitation or vomiting: When food is unable to pass through the esophagus, it may come back up undigested. This condition occurs for about 40% of people with esophageal cancer. Vomiting of food or blood may also occur, especially if the tumor is bleeding. 

to be continued…