Generality
Esophageal cancer is a neoplastic process that originates from the tissues of the esophagus (the channel through which ingested foods and liquids reach the stomach).
The main factors that predispose to the onset of esophageal cancer are chronic alcohol ingestion, tobacco use, achalasia, gastroesophageal acid reflux and / or Barrett's esophagus.
At the onset, esophageal cancer manifests itself with swallowing problems : usually, the difficulties appear gradually, first for solid foods and, subsequently, for liquid ones. Other symptoms are progressive weight loss, reflux, chest pain and hoarseness. Over time, esophageal cancer can grow, invade neighboring tissues and also spread to other parts of the body.
Diagnosis is established with endoscopy, followed by computed tomography (CT) and endoscopic ultrasonography for staging.
Treatment varies depending on the stage of esophageal cancer and generally consists of surgery, in association or otherwise with chemotherapy and / or radiotherapy. Long-term survival is low, except in cases with localized disease.
Anatomy outline
- The esophagus is a muscle-membranous duct, about 25-30 centimeters long and 2-3 cm wide, which connects the pharynx to the stomach. This structure is located almost entirely in the chest, in front of the spine.
- The walls of the esophagus consist of a layer of epithelial lining similar to that of the mouth, while they are surrounded externally by two layers of smooth musculature.
- By contracting in the act of swallowing, the muscular component pushes the food downwards, towards the stomach, from which the exodagus is separated by a valve, called cardias, which prevents the ingested foods and gastric juices from rising.
- The mucosa of the esophagus is rich in mucus-producing glands, which has the function of lubricating the walls facilitating the passage of swallowed food.
Causes and risk factors
Esophageal cancer is caused by the growth and uncontrolled proliferation of some cells that make up the organ, induced by an alteration in their DNA. The reasons behind this event are not yet completely clear, but it seems that the neoplastic process may depend on the combination of genetic factors, diet, lifestyle and previous esophageal pathology (such as reflux esophagitis, caustic stenoses) and Barrett's esophagus). The pathogenesis common to these conditions would be the presence of a chronic inflammatory state of the esophageal mucosa which, through various degrees of dysplasia, would lead to neoplasia over time.
The main factors that can help determine esophageal cancer are:
- Alcoholism;
- Use of tobacco (smoked or chewed);
- Esophageal achalasia (pathological condition that affects the muscles of the esophagus and makes swallowing difficult);
- Chronic inflammation, including peptic esophagitis, gastro-oesophageal reflux and / or Barrett's esophagus;
- Ingestion of hot food and beverages;
- Diet low in fresh fruit and vegetables;
- Increased intake of red meat;
- Obesity.
Other conditions that can promote esophageal cancer are:
- Human papilloma virus infections;
- Palm and plantar tylosis (rare hereditary disease characterized by thickening of the skin of the palms of the hands and the soles of the feet);
- Caustic injuries;
- Previous radiant therapies;
- Plummer-Vinson syndrome (a condition characterized by the clinical triad of dysphagia, iron deficiency anemia and membranes in the esophageal lumen).
Other risk factors for esophageal cancer are:
- Age: the incidence increases progressively after 45-50 years; most cases are found between 55 and 70 years old;
- Sex: men are more affected than women, with a ratio of 3 to 1.
Main types
Depending on the tissue from which it originates, two main forms of esophageal cancer can be distinguished:
- Squamous cell (or squamous cell) carcinoma : it is the most common of esophageal tumors (it represents about 60% of cases): it originates from the squamous cells that cover the internal wall of the organ.
Usually, it develops in the upper and intermediate portion, but can arise throughout the esophageal canal.
- Adenocarcinoma : constitutes about 30% of tumors of the esophagus and derives from the transformation in neoplastic sense of the cells of the glands responsible for mucus production. Adenocarcinoma occurs more frequently in the last section of the esophageal canal, near the junction with the stomach (lower third). This neoplasm can also originate from islands of gastric mucosa off-site or from glands of the cardia or submucosa of the esophagus.
Less common malignant esophageal tumors include sarcoma, primitive small cell carcinoma, the carcinoid and primitive malignant melanoma.
In about 3% of cases, esophageal cancer can originate from the metastasization of other neoplasms (especially melanomas and breast cancer). These processes usually involve the loose connective tissue around the esophagus, while primitive carcinomas originate in the mucosa or submucosa.
Signs and symptoms
To learn more: Symptoms Tumor in the esophagus »
In the early stages, esophageal cancer tends to be asymptomatic.
The most frequent onset symptom is the difficulty in ingesting food (dysphagia), which generally coincides with the narrowing of the lumen of the esophagus.
At the beginning, the patient experiences a difficulty in swallowing or a feeling that solid foods stop during their passage to the stomach; this episodic manifestation becomes constant and then extends to semi-solid foods and, finally, to liquids and saliva. This constant progression suggests an expansive malignant process, rather than an esophageal spasm or a peptic stenosis. In the most advanced stages of tumor development, swallowing can also become painful ( odynophagia ). When the mass of the tumor obstructs the descent of the food along the esophagus episodes of regurgitation may occur.
Weight loss is inexplicable and almost constant, even when the patient has a good appetite.
Tumor growth out of the esophagus can cause:
- Paralysis of the vocal cords, hoarseness and / or dysphonia (the alteration of the tone of voice is secondary to the compression of the recurrent laryngeal nerve, which innervates all the intrinsic muscles of the larynx);
- Hiccups or paralysis of the diaphragm;
- Chest pain, which often radiates to the back.
Intraluminal involvement of the neoplastic mass may cause:
- Painful cramps of the esophagus;
- Heartburn or frequent eructations (reflux);
- He retched;
- Iron deficiency anemia;
- Expulsion of blood with vomit (hematemesis);
- Evacuation of picee feces (melena);
- Inhalation cough and bronchopneumonia.
In more advanced forms can also form fluid in the lining of the lung (pleural effusion), with the appearance of dyspnea (difficulty in breathing). Other manifestations may include: increased liver size and bone pain, generally associated with the presence of metastases.
The esophagus is drained along its entire length by a lymphatic plexus, therefore a lymphatic diffusion is frequent through the lymph node chains on the sides of the neck and above the clavicle, with an appreciable swelling at these levels.
Esophageal cancer usually metastasizes in the lungs and liver and sometimes in distant locations (eg bones, heart, brain, adrenal glands, kidneys and peritoneum).
Diagnosis
The diagnosis of esophageal cancer is formulated with the endoscopy of the esophagus (esophagoscopy), associated with biopsy and cytological examination.
During this investigation, a flexible, thin and illuminated instrument (called an endoscope) is introduced from the mouth to allow the physician to directly observe the morphological structure of the esophagus and stomach.
Furthermore, it is possible that the patient is subjected to an x-ray of the esophagus with contrast medium . This survey involves the execution of a sequence of radiographic images of the esophagus after the patient has ingested a barium-based preparation, capable of making any obstructive lesion more evident and excluding the presence of associated diseases.
The association of the two procedures (esophagoscopy and radiography) increases the diagnostic sensitivity up to 99%.
Clinical staging
Once the esophageal tumor has been identified, further tests are required to complete the diagnostic tests, in order to establish the level of infiltration and exclude the presence of distant metastases. Staging of the disease is an important step in selecting the most appropriate treatment for each patient.
- To more accurately determine how deep the infiltration of the esophageal wall layers is and to highlight the involvement of regional lymph nodes, echoendoscopy is also used.
- In tumors of the middle or upper third of the esophagus, in which an involvement of the bronchial tree and trachea is possible, a bronchoscopy may be necessary.
- Instead, to verify localizations of the lymph node disease or distant diffusion (liver, lung and structures adjacent to the esophageal wall), computerized tomography (CT) of abdomen and thorax or CT combined with positron emission tomography ( PET-CT).
Treatment
Read also: Drugs for the treatment of esophageal cancer "
The choice of therapeutic options depends on the staging of the esophageal tumor, its size and location.
The most common standard treatment is esophagectomy . This surgery is performed under general anesthesia and involves almost complete resection of the esophagus, combined via abdominal, thoracic and cervical. The continuity of the digestive system is restored by suturing the esophagus at the level of the neck with the stomach (more rarely with the colon), adequately prepared through an abdominal procedure.
Sometimes, chemotherapy or radiotherapy performed before the operation can greatly reduce the size of the tumor, so as to greatly increase the chances of success of the surgery.
Other treatment modalities that can be used individually, associated or sequentially based on the tumor stage are:
- Radiotherapy : usually used in combination with chemotherapy for patients who are not candidates for surgery, including those with advanced disease.
- Chemotherapy : esophageal tumors are not very sensitive to chemotherapy treatment only. Response rates range from 10 to 40%, but overall responses are incomplete (minor tumor reduction) and temporary. No drug is significantly more effective than another. In most cases, cisplatin and 5-fluorouracil are used in combination. However, many other drugs (such as mitomycin, doxorubicin, vindesine, bleomycin and methotrexate) are also active against squamous cell carcinoma.
Prevention
A good prevention of esophageal cancer is based on abstention from cigarette smoking, on avoiding excessive consumption of alcohol, on weight control and on adopting a healthy and light diet, rich in fruit and vegetables.
Another preventive measure is to reduce the risk of gastroesophageal reflux, which can predispose to chronic inflammatory states: this is achieved by reducing the consumption of coffee, alcohol and cigarettes, but also overweight and obesity.
