This is a protocol for a Cochrane Review (prognosis). The objectives are as follows:

We aim to compare overall survival in people with recurrence and second primary lung cancer (SPLC) after lung cancer surgery. If survival differs between those people categorised as having index lung cancer recurrence and those categorised as having SPLC, it might be possible to identify the definition that has the best discriminatory capacity from the various published definitions of these conditions, so that it can be used in future.