Overview
Esophageal cancer is the most common among malignant tumors, and among them, esophageal cancer is the most common. China is the world’s most prevalent region for esophageal cancer, and its mortality rate is the highest in the world.
Diagnosis
The most common diagnostic methods are barium X-ray, exfoliative cytology and fiberoptic endoscopy. With the progress of science and technology, CT scan of chest and endoscopic ultrasonography of esophagus have been applied in clinical practice. The first 3 examinations are essential in clinical practice, especially fiberoptic endoscopy, which is superior to X-ray examination in terms of localization, length determination, detection of a second cancer and exclusion of benign strictures.
Barium meal X-ray is not easy to show the lesion in early esophageal cancer. If the examining physician follows the routine, the barium is too thick and too thin, drinks barium in a big mouth, and simply takes the frontal and lateral observation, it can lead to a missed diagnosis. It is necessary to adjust the barium meal, make the patient swallow it in small bites and observe carefully in multiple axes.
The early X-ray signs are.
(1) thickened mucosal folds, tortuous or dashed interruptions, or hairy edges of the esophagus.
②Small filling defects, either flatter or polyp-like, with a minimum diameter of about 0.5 cm.
(③Small ulcerative niche, from 0.2 to 0.4 cm in diameter.
④Limited canal wall stiffness or with barium retention. Due to the mild lesion, the positive rate of barium X-ray examination in early cases is only about 70%. In intermediate and advanced cases, the signs are clear, and most of them are luminal narrowing, filling defect, loss of peristalsis, mucosal disorder, ulcerative niche shadow and soft tissue shadow around the lesioned segment of the esophagus. In the intraluminal type, a barium x-ray study shows a large filling defect and a widening of the lumen of the segment.
Esophageal exfoliative cytology is a simple method with little pain and low false-positive rate, and is the most practical method for large area screening in high prevalence areas.
Some authors adopt segmentation and multiple retrieval to locate the esophagus, for example, if the distance from the incisor is more than 25 cm, a major resection of the esophagus should be performed and the neck should be reconstructed; if the distance is between 25 and 35 cm, a major resection of the esophagus above the arch should be performed and reconstructed; if the distance is less than 35 cm, the esophagus below the arch can be resected and reconstructed. However, this method has some errors, especially when the lesion is located at the junction of the above-mentioned fixed points. Endoscopic examination should still be taken to locate the lesion in hospitals where it is available. The positive rate of decidual cytology decreases in advanced cases. This is due to the narrow heavy mesh sleeve that does not pass through the tumor segment and is worth noting. Contraindications for decidual cytology are hypertension, esophageal varices, severe cardiac and pulmonary disease.
The third commonly used diagnostic method is endoscopy. Since the gradual replacement of the metal rigid endoscope by the fiberoptic scope in the 1970s, the safety and accuracy of the examination have been greatly improved due to the bendable patient’s free position, good illumination, and wide view (and slight magnification).
The indications for fiberoptic esophagoscopy are.
①If the patient is asymptomatic or mildly symptomatic in the early stage, and there are no positive X-ray findings and positive exfoliative cytology.
(2) X-ray findings that are not easily distinguished from benign lesions, such as symmetrical, smooth strictures resembling benign scar strictures or submucosal wall lesions resembling smooth muscle tumors.
(③) Diagnosed benign esophageal lesions such as diverticula or pancreatic dyschondria, when there is a significant increase in symptoms.
④Follow-up of patients who have received various treatments to observe the efficacy.
Fiberoptic endoscopy also has contraindications, including.
① malignant body disease ;
②Severe cardiovascular disease;
③Acute respiratory tract infection.
Contraindications to metal tubing in the past, such as hunchback deformity esophageal varices, are no longer considered in fiberoptic endoscopy. In early esophageal cancer, the detection rate of fiberoptic microscopy can reach 85.2%, and the early microscopic manifestations are.
①Limited erosion is the most common, accounting for 53%;
②Local mucosal congestion with less clear boundary accounts for 38.5%;
③ rough small particles accounted for 27.4%. Other less common were small swellings accounting for 9.4%, small ulcers accounting for 6.8%, and small plaques accounting for 6.8%. In order to improve the detection rate of fiberoptic endoscopy, biopsy staining (toluidine blue or Lugol sulphur solution) can be used in combination with the examination process. The microscopic findings of intermediate and advanced esophageal cancer are clearer and easier to identify. It appears as nodules or cauliflower-like swellings, congested and edematous esophageal mucosa or pale and stiff, bleeding easily when touched, ulcers and lumen narrowing. If the esophageal lesion is located in the upper thoracic or cervical segment, fiberoptic bronchoscopy should be performed at the same time as esophagoscopy to rule out tracheal or bronchial extrusion or invasion.
The role of chest CT in the diagnosis and treatment of esophageal cancer is evaluated differently. Some think that CT is helpful for staging, determination of resection possibility and prognosis estimation. However, some think that such examination is not useful, and some authors report that the accuracy rate of CT staging is only 60%.
A brief summary of the meaningful positive CT findings are as follows.
(1) The trachea and bronchi may be invaded, and CT shows that the trachea and bronchi are displaced by extrusion, their posterior walls are compressed and convex to the lumen, and the fatty layer between them and the esophagus disappears indiscernibly.
(2) The pericardium or aorta may be invaded, and the fatty layer between the pericardium and aorta and the esophagus of the lesion disappears while the fatty layer between the upper and lower ends of the tumor site still exists. Or the angle between the esophageal lesion and the circumference of the aorta is equal to or greater than 90 degrees.
③Mediastinal and abdominal lymph node metastasis, the diameter of enlarged lymph node should be more than 1cm.
The sensitivity of CT is 88% for invasion of the aorta, 98% for tracheobronchus, and 100% for pericardium, and the sensitivity of CT for lymph node metastasis is 60% for peri-esophageal lymph node metastasis, 76% for abdominal lymph node metastasis, and its specificity is 93%. The sensitivity of CT for liver metastases was 78%, and the specificity was 100%. Objectively, the CT findings cannot identify the presence or absence of metastases in lymph nodes of normal size, and it is not possible to be certain that enlarged lymph nodes are due to inflammation or metastases, much less to detect metastatic lymph nodes less than 1 cm in diameter. As mentioned above, the accuracy of determining the invasion of external organs is limited. Therefore, the chance of surgery should not be passed up based on the “positive finding” of CT alone.
Endoscopic ultrasonography of the esophagus
In recent years, esophageal ultrasound endoscopy (EUS) has been gradually used in clinical practice. However, due to the high cost of the equipment, it will not be widely used in the foreseeable future. Endoscopic ultrasound whose generation system works through a water-filled capsule, normally the first mucosal layer is echogenic, the second mucosal muscle layer is a dark area, and the third submucosal layer is echogenic.
The advantages of this new examination method are.
①The depth of lesion infiltration in the esophageal wall can be accurately determined with an accuracy rate of 90%.
(2) Abnormally enlarged lymph nodes outside the wall, including those far from the lesion site, can be detected, with a display rate of 70%.
(③) It can quickly and easily distinguish whether the lesion is located in the esophagus or outside the wall.
However, there are shortcomings.
①The detection range is limited, reaching only 4 cm away from the center of the main stem of the instrument, which is the area close to the esophagus or stomach.
② Structures that interfere with ultrasound cannot exist in between.
③When the lesion segment is severely narrowed and the probe cannot pass, the lymph nodes below it next to the esophagus cannot be detected.
Ultrasound examination of the abdomen can detect retroperitoneal lymph node metastasis, liver metastasis, etc., which helps to periodically and determine the indications for surgery. Especially for patients with pancreatic cancer, when enlarged retroperitoneal retrostomach lymph nodes are detected, the size of the enlarged lymph nodes can often be seen to be much larger than judged by ultrasound, and the disease has reached a stage where radical resection is not possible.
Treatment measures
Esophageal cancer is a common cancer in China, and the two types of treatment are surgery and radiation, which have positive effects. Through a lot of clinical practice, both thoracic surgery and radiation therapy departments have accumulated rich experience and the treatment effect is in the forefront among international counterparts.
One of the trends in surgical treatment of esophageal cancer is the gradual expansion of surgical indications; in the 1960s, people used to choose radiotherapy over surgery for lesions located in the cervical and upper thoracic segments, which accounted for only 5% of the patients admitted to surgery. This bias has changed, and since the 1970s, more and more patients with esophageal cancer in this segment have been treated surgically with satisfactory results. The number of patients admitted is 15-20% of the total, and the outlook is to continue to increase. Another indication for expansion is the increasing number of patients with esophageal cancer undergoing surgical treatment with various medical conditions.