Esophageal Squamous Cell Carcinoma (ESCC) is a type of cancer that originates in the squamous cells, which are the flat, thin cells lining the esophagus. This muscular tube serves as the pathway for food from the throat to the stomach. ESCC typically develops in the upper and middle sections of the esophagus and is one of the two primary forms of esophageal cancer.
Risk Factors and Causes
Long-term tobacco use and heavy alcohol consumption are recognized as significant contributors to the development of ESCC, often acting synergistically to multiply the risk. Dietary habits also play a role, as diets low in fruits and vegetables are associated with an increased risk. Consuming very hot liquids frequently can damage the esophageal lining, thereby increasing the risk.
Certain medical conditions can predispose individuals to ESCC. Achalasia, a rare disorder affecting the muscles in the lower esophagus that impairs swallowing, is linked to a higher risk of ESCC, with cancer potentially developing 15–20 years after symptom onset. Plummer-Vinson syndrome, characterized by iron deficiency anemia and thin tissue webs in the upper esophagus, also elevates the risk. Geographically, ESCC incidence varies widely, with higher rates observed in specific regions like parts of Southern and Eastern Africa and Central Asia, sometimes called the “esophageal cancer belt.”
Common Symptoms
Progressive dysphagia, or difficulty swallowing, is often the first and most common symptom of ESCC. This symptom typically begins with solids and gradually worsens, eventually making it difficult to swallow liquids as the tumor grows and narrows the esophagus.
Other common symptoms include unintentional weight loss, which occurs because swallowing difficulties prevent adequate nutritional intake. Some individuals may experience chest pain or pressure. Hoarseness or a persistent change in voice, along with a chronic cough, can also indicate the presence of ESCC. Painful swallowing, known as odynophagia, might also occur. These symptoms frequently appear only when the tumor has grown large enough to cause a noticeable obstruction.
The Diagnostic Process
The initial step in diagnosing ESCC typically involves an upper endoscopy. During this procedure, a thin, flexible tube with a camera is inserted down the throat to visualize the lining of the esophagus. If any suspicious areas are found, a biopsy, which is a small tissue sample, is collected through the endoscope.
The collected biopsy samples are then sent to a laboratory for pathological analysis to confirm the presence of cancer cells. Once ESCC is confirmed, further tests are conducted to determine the extent of the cancer, a process known as staging. Imaging tests commonly used for this purpose include computed tomography (CT) scans of the chest and abdomen to identify the primary tumor and any spread to lymph nodes or distant organs like the liver or lungs.
A positron emission tomography (PET) scan, often combined with a CT scan, is also employed to detect cancer spread throughout the body. Endoscopic ultrasound (EUS), which combines an ultrasound probe with an endoscope, is increasingly used to assess the depth of the tumor within the esophageal wall and evaluate nearby lymph nodes. In cases where upper or mid-esophageal tumors might involve the airway, a bronchoscopy may be performed.
Treatment Approaches
Treatment strategies for ESCC are tailored based on the cancer’s stage and the patient’s overall health. For very early-stage ESCC, where the cancer is confined to the innermost layers of the esophagus, endoscopic treatments may be an option. These minimally invasive procedures, such as endoscopic mucosal resection or submucosal dissection, involve removing the cancerous tissue through the endoscope.
For localized or locally advanced ESCC, a multimodal approach is generally employed. This often involves a combination of surgery, chemotherapy, and radiation therapy. Chemoradiation, which is chemotherapy and radiation therapy given concurrently, is a common approach before surgery to shrink the tumor and treat potential microscopic spread. Esophagectomy, the surgical removal of part or all of the esophagus, is a primary treatment for resectable tumors, often followed by reconstruction.
In cases of advanced or metastatic ESCC, where the cancer has spread to distant organs or lymph nodes, the focus of treatment shifts to controlling the cancer and managing symptoms. Systemic treatments are used, which include chemotherapy, targeted therapy, and immunotherapy. Immunotherapy helps the body’s immune system recognize and fight cancer cells.
Staging and Prognosis
Staging describes the cancer’s size, its depth of invasion, and whether it has spread to nearby lymph nodes or distant parts of the body. The staging system helps doctors determine the most appropriate treatment plan and provides an indication of the likely outcome. Lower stages, such as Stage 0 or I, indicate cancer that is localized or has only grown into the superficial layers of the esophagus.
The prognosis for ESCC is better when diagnosed at earlier stages, with higher survival rates for localized disease. As the cancer progresses to regional lymph node involvement or distant metastasis, the prognosis becomes less favorable. Survival rates are statistical averages and cannot precisely predict an individual’s outcome. A person’s specific prognosis is influenced by many factors, including their overall health, the cancer’s response to treatment, and other individual circumstances.