All units now have GP referral proformas
What are the warning symptoms?
Most patients with oesophageal carcinoma present late because the early warning symptoms are fairly nondescript. The principal symptom is dysphagia and up to 25 per cent of patients presenting with a convincing story of dysphagia will be found to have a carcinoma.
But dysphagia only develops when a significant degree of oesophageal obstruction has occurred and so often represents advanced disease. Early-warning symptoms such as indigestion are often assumed to be a flare-up of longstanding acid reflux and so ignored until significant dysphagia occurs. To confuse matters, dysphagia is common in acid reflux disease both from the development of a peptic stricture and also from oesophageal inflammation without a stricture (30 per cent of reflux patients can have non-obstructive dysphagia).
The Department of Health has recently produced guidelines for the referral and investigation of patients with suspected upper gastrointestinal cancer. Many cancer units have produced GP referral proformas with these guidelines; essentially any patient complaining of dysphagia or any patient with a new indigestion symptom if aged over 55 (with one other high-risk warning symptom or sign) should be referred for investigation.
Barrett's oesophagus is a known high-risk factor. Why is this, and is it feasible to consider surveillance of this at-risk group?
Barrett's oesophagus is the name for the development of a columnar lining in the lower oesophagus as a consequence of excessive acid reflux. Its importance lies in its ability to progress to invasive malignancy through a metaplasia, dysplasia, carcinoma sequence. About 10 per cent of the patients with severe reflux disease will develop Barrett's, and possibly about 10 per cent of these, over a lifetime, will develop a carcinoma. It's been estimated that an individual patient would need to be followed up, by surveillance endoscopy, for between 100 to 300 patient follow-up years before a tumour was detected.
So while it is a recognised as a pre-malignant condition the actual risk of a patient getting cancer is not high and most adenocarcinomas present at a late stage in patients who are not previously known to have Barrett's oesophagus. Consequently the question of surveying this group of patients is controversial with several studies showing no real benefit for the high cost that would be involved.
Others argue the tumours that are detected are at an earlier and therefore curable stage of disease (assuming mortality and morbidity of surgery is low) and this justifies a surveillance programme. For patients to be considered for surveillance clearly they must be suitable for oesophagectomy if an early carcinoma develops.
Recently there's been some experimental evidence suggesting a Barrett's oesophagus can be returned to a squamous lining by ablation with either photodynamic therapy or by thermal ablation using laser or argon gas coagulation. If this proves to reduce the risk of developing adenocarcinoma then gastroenterologists may become more enthusiastic about surveillance.
What approaches to treatment are there?
The treatment of oesophageal cancer can be prolonged, morbid and taxing for the patient so it is important to determine at the outset the realistic chance of cure.
Unfortunately most tumours present late and metastasise early and, in addition, the patient group is often elderly with significant co-morbid disease. Consequently only
30-40 per cent of patients will be considered for curative treatment. So the investigation and staging strategy is aimed at finding those patients who would, first, be suitable for radical treatment for cure and, second, to minimise as much as possible operating on patients who have metastatic disease.
Despite identifying patients not fit for radical treatment or who have metastatic disease, unfortunately the majority of those selected for radical treatment die of their disease within one to two years. This undetected early dissemination of disease reflects the limitations of current staging investigations and treatment modalities.
At present we stage patients with oesophageal cancer with chest and abdominal CT (looking for evidence of metastatic disease to lung, liver, adrenal glands or lymph nodes) and with endoscopic ultrasound. The ultrasound probe is attached to the end of a conventional endoscope and, at the moment, gives the most accurate local stage of the tumour. For tumours encroaching on the lower oesophagus and abdominal cavity, a staging laparoscopy is performed to exclude intra-peritoneal metastases, malignant ascites or liver metastases too small to be detected by CT.
Surgical resection aims to remove all the malignant tissue and up till now is the only treatment modality that has been shown to provide prolonged survival, but the surgery is a major operation with a wide range of reported mortality rates. With the concentration of oesophageal resections at more specialised units post-operative mortality should now be no more than 5 per cent. Despite excluding patients with metastatic disease overall cure rates remain poor with only about 20 per cent surviving five years. Surgical resection, however, can produce excellent cure rates if the tumour is confined to the mucosa or submucosa, but unfortunately very few patients present with this early-stage disease.
In an attempt to improve outcome a recent MRC trial using two cycles of preoperative cisplatin and 5-FU followed by surgery compared with surgery alone showed a survival benefit for the chemotherapy-treated group.
For tumours other than those confined to the mucosal layers of the oesophagus
it is now routine practice to treat patients with chemotherapy before surgical resection.