Cause-specific survival is commonly estimated in cancer clinical trials and only those deaths which can be attributed to the cancer in question are considered to be events, while all other deaths are considered censorings. Using cause-specific survival to estimate net survival requires that reliably coded information on cause of death is available. The distinguishing feature of survival analysis is that at the end of the follow-up period the event (such as death due to cancer) will probably not have occurred for all patients. For these patients the survival time is said to be censored, indicating that the observation period.
