Achalasia complicated by oesophageal squamous cell carcinoma: a prospective study in 195 patients.

To determine the incidence of oesophageal carcinoma in patients with achalasia and to establish the efficacy of endoscopic surveillance, 195 consecutive patients with achalasia (90 men and 105 women, mean age 52 years), who were treated by pneumatic dilatation in our institution between 1973 and 1988 were prospectively studied. None of the patients had undergone cardiomyotomy. Follow up totalled 874 person years after pneumatic dilatation. In this period three patients developed an oesophageal squamous cell carcinoma. The mean age at diagnosis of the oesophageal carcinoma was 68 years (37, 77, and 89 years). The mean period between the onset of dysphagia and the diagnosis of the tumour was 17 years (19, 28, and 5 years); the mean interval between the diagnosis of achalasia and carcinoma was 5.7 years (5, 8, and 4 years). The incidence of oesophageal squamous cell carcinoma in this series (3.4/1000 patients per year) is significantly higher than the statistically expected incidence (0.104/1000 patients per year) using age and sex specific incidence data from the population of the Netherlands (Poisson statistics: p less than 0.001). The risk of developing oesophageal squamous cell carcinoma in patients with achalasia is therefore increased 33 fold. Periodic endoscopy showed the potential for detecting early stage oesophageal carcinoma in two cases but a larger study with a longer follow up is required to determine the efficacy of endoscopic screening in improving the prognosis for patients with achalasia who develop oesophageal squamous cell carcinoma.