Hi,

I’m currently working on a retrospective analysis of survival from a very rare cancer (N = 23) and I have a question about what is the most appropriate way calculating the median overall survival in a retrospective study.

In my data, some patients had complete response to treatment and never recurred and consequently their follow-up is longer (~ 10 years). My question is if I should right-censor these patients on a estipulated follow-up maximum time (example, 5 years) or if I should use the complete time of follow-up to calculate the median overall survival. This problem does not happen in clinical trials because the end of follow-up will be the end of the study and patients will have similar time. However, for observational data, I have not found any discussion on that.

In my project we are not investigating correlates of mortality but describing outcomes and survival of patients with this specific rare cancer.

Thanks in advance,

Felippe