NEOPLASMS OF THE OESOPHAGUS
Benign tumoursBenign tumours of the oesophagus are relatively rare. True papillomas, adenomas and hyperplastic polyps do occur, but the majority of ‘benign’ tumours are not epithelial in origin and arise from other layers of the oesophageal wall [gastrointestinal stromal tumour (GIST), lipoma, granular cell tumour].
Most benign oesophageal tumours are small and asymptomatic, and even a large benign tumour may cause only mild symptoms.
The most important point in their management is to carry out an adequate number of biopsies to exclude malignancy.
Malignant tumours
Carcinoma of the oesophagusIn general, it is a disease of mid to late adulthood, with a poor survival rate. Only 5–10% of those diagnosed will survive for 5 years .
Pathology and aetiology
Squamous cell cancer and adenocarcinoma are the most common types.Squamous cell carcinoma generally affects the upper two-thirds of the oesophagus and adenocarcinoma the lower one-third.
Worldwide, squamous cell cancer is most common, but adenocarcinoma predominates in the west and is increasing in incidence.
Geographical variation in oesophageal cancer
The incidence of oesophageal cancer varies more than that of any other cancer. The cause of the disease in the endemic areas is not known, but it is probably due to a combination of fungal contamination of food and nutritional deficiencies.Away from the endemic areas, tobacco and alcohol are major factors in the occurrence of squamous cancer.
In many western countries, the incidence of squamous cell cancer has fallen or remained static, but the incidence of adenocarcinoma of the oesophagus has increased dramatically. A similar rate of increase in GORD over the same period, which mirrors an increase in obesity in the west, is likely to be an important factor, particularly through the link to Barrett’s oesophagus.
Both adenocarcinomas and squamous cell carcinomas tend to disseminate early.
Tumours can spread by either direct invasion through the oesophageal wall, via lymphatics or in the bloodstream.
Direct spread occurs both laterally, through the component layers of the oesophageal wall, and longitudinally within the oesophageal wall. Longitudinal spread is mainly via the submucosal lymphatic channels of the oesophagus.
The pattern of lymphatic drainage is not segmental, as in other parts of the gastrointestinal tract. Consequently, the length of oesophagus involved by tumour is frequently much longer than the macroscopic length of the malignancy at the epithelial surface. Lymph node spread occurs commonly. Although the direction of spread to regional lymphatics is predominantly caudal, the involvement of lymph nodes is potentially widespread and can also occur in a cranial direction. Haematogenous spread may involve the liver, lungs, brain and bones. Tumours arising from the intra-abdominal portion of the oesophagus may also disseminate transperitoneally.
Clinical features
Most oesophageal neoplasms present with mechanical symptoms, principally dysphagia, but sometimes also regurgitation, vomiting, odynophagia and weight loss. Clinical findings suggestive of advanced malignancy include recurrent laryngeal nerve palsy, Horner’s syndrome, chronic spinal pain and diaphragmatic paralysis.Cutaneous tumour metastases or enlarged supraclavicular lymph nodes may be seen on clinical examination and indicate disseminated disease.
Patients with early disease may have non-specific dyspeptic symptoms or a vague feeling during swallowing. Some are diagnosed during endoscopic surveillance of patients with Barrett’s oesophagus. The widespread use of endoscopy as a diagnostic tool does provide an opportunity for early diagnosis. Biopsies should be taken of all lesions in the oesophagus, no matter how trivial they appear.
Investigation
Endoscopy is the first-line investigation for most patients. It provides a direct view of the oesophageal mucosa and any lesion allowing its site and size to be documented with its biopsy for accurate diagnosis.General assessment and staging
Once the initial diagnosis of a malignant oesophageal neoplasm has been made, patients should be assessed first in terms of their general health and fitness for potential therapies. Their preferences should also be considered. Most potentially curative therapies include radical surgery, although chemoradiotherapy is an alternative in squamous cell carcinoma.Patients who are unfit for, or who do not wish radical treatments should not be investigated further, but should be diverted to appropriate palliative therapies, depending on symptoms and current quality of life. Only those patients suitable for potentially curative therapies should proceed to staging investigations to rule out haematogenous spread and then to assess locoregional stage.
In general, surgery alone should be reserved for patients with early disease, and multimodal therapy should be used in patients with locally advanced disease, in whom the chance of cure by surgery alone is small (generally less than 20%).
The most widely used pathological staging system is the World Health Organization (tumour–nodes–metastasis TNM) classification.
Blood tests
These are of limited value, and, to date, no reliable tumour marker for oesophageal cancer has been isolated from peripheral blood.Transcutaneous ultrasound
It is difficult to visualize mediastinal structures with transcutaneous
ultrasound. The technique is therefore used mainly to assess spread to the liver. Haematogenous spread can be more fully assessed by combining ultrasound with chest radiography, although this combination is less accurate than CT scanning.
Computerized tomography
CT scanning is the modality most used to identify haematogenous metastases. Distant organs are easily seen and metastases within them visualized with high accuracy (94–100%).
Magnetic resonance imaging scanning
MRI does not expose the patient to ionising radiation and needs no intravascular contrast medium. Distant metastases are identified by MRI but there do not seem to be additional benefits over CT.Endoscopic ultrasound
After haematogenous spread, the two principal prognostic factors for oesophageal cancer are the depth of tumour penetration through the oesophageal wall and regional lymph node spread.Although CT will detect distant metastasis, its limited axial resolution precludes a reliable assessment of both the depth of wall penetration and lymph node involvement.
Laparoscopy
This is a useful technique for the diagnosis of intra-abdominal and hepatic metastases. It has the advantage of obtaining tissue samples and is the only modality able to detect peritoneal tumour seedlings.Treatment of malignant tumours
PrinciplesAt the time of diagnosis, around two-thirds of all patients with oesophageal cancer will already have incurable disease. The aim of palliative treatment is to overcome debilitating or distressing symptoms while maintaining the best quality of life possible for the patient.
As dysphagia is the predominant symptom in advanced oesophageal cancer, the principal aim of palliation is to restore adequate swallowing.
The principle of oesophagectomy is to deal adequately with the local tumour in order to minimise the risk of local recurrence and achieve an adequate lymphadenectomy to reduce the risk of staging error.
The complication rate following oesophagectomy remains high.The most common of these is respiratory, anastomotic leakage, chylothorax and injury to the recurrent laryngeal nerves. The most common late problem is benign anastomotic stricture.
Non-surgical treatments
While it is clear that chemoradiotherapy does offer a prospect of cure for patients who may not be fit for surgery, particularly in squamous cell carcinoma, the high rate of locoregional failure has meant that surgery remains the mainstay of attempted curative treatments for both adenocarcinoma and squamous cell carcinoma in patients who have potentially resectable disease and are fit for oesophagectomy.
Palliative treatment
A variety of expanding metal stents were developed for placement under endoscopic and/or radiological control for relief of dysphagia.Endoscopic laser treatment
May be used to core a channel through the tumour. It is based on thermal tumour destruction. It produces a worthwhile improvement in swallowing, but it has to be repeated every few weeks.