The 'stage' of any cancer is a description of its size, local spread and distant spread. Defining the stage is crucial in deciding the most appropriate treatment and whether it is possible to aim to cure the disease. Scans are the most important method of working out the stage of the disease.
Oncologist will use internationally recognised systems of staging, but the principles are to decide the following:
The main concern whether the growth is confined to the oesophagus or whether it has spread to other organs.
Where the disease is localised then it may be possible to aim for a cure, otherwise palliation is the best approach.