Even when the surgeon feels they have completely removed a cancer it sometimes happens that microscopic cancer cells are left behind. These will continue to grow and cause the cancer to return (recurrence).

For this reason doctors have suggested that a course of radiotherapy to the chest be given as a precaution, when a non-small cell carcinoma of the lung, such as a squamous cell cancer, has been completely removed.

However, studies (PORT Trials Group) have shown that giving radiotherapy after complete removal of a lung cancer did not give any additional benefit in terms of survival, and might actually be harmful in a small number of people. Because of these results it is generally recommended that radiotherapy should not be given after surgery for non-small cell lung cancer if the surgeons feel the tumour has been completely removed. Radiotherapy would usually only be considered after surgery, if your specialist felt there may have been some cancer cells left behind or if a number lymph nodes are also involved..