Achalasia is a disorder of the gullet (oesophagus) where it loses the ability to move food along. The valve at the end of the gullet also fails to open and allow food to pass into your stomach.
As a result, food gets stuck in your gullet and is often brought back up.
A ring of muscle called the lower oesophageal (cardiac) sphincter keeps the opening from the gullet to the stomach shut tight to prevent cancer of the oesophagus (gullet) is slightly increased.
The increased risk is likely to be most significant in long-term untreated achalasia. It's therefore important to get appropriate treatment for achalasia straight away, even if your symptoms are not bothering you.
According to Cancer Research UK, compared with the general population:
men with achalasia have an eight to 16 times higher risk of oesophageal cancer
women with achalasia have a 20 times higher risk of one particular type of oesophageal cancer (adenocarcinoma)
However, cancer of the oesophagus is very uncommon and although your risk is slightly increased, it remains highly unlikely.