I am finishing up the data collection for my retrospective cohort study, which I have designed with the intention of conducting survival analysis. Our outcomes of interest are recurrence, metastasis, and death following various surgical treatments for a type of cancer. A few dozen cases had only 1-2 weeks of follow-up post-treatment. I am wondering whether I need to include these cases considering the fact that 1-2 weeks is really not long enough for the outcomes of interest to occur. At the same time, I wouldn't want to harm the study's internal validity by excluding them. Indeed, it would be simple enough to include the cases and censor them on the last day of follow-up, even if it is a trivial length of time.