Analysis for progression free survival (PFS), and Dose intensities effect on PFS.

Hi every Body,

The project that we are doing is related to a drug that is given to patients having colorectal cancer, after they have failed all lines of treatment, we are trying to find how dose intensity will have an effect on survival and quality of life for patients, one statistical point that is asked, as our primary endpoint is progression-free survival and overall survival, how will the primary endpoint be analysed? what analysis we will use?

The second question is, will dose intensity be used as a categorical or continuous variable?

How will be the effect of those intensities on progression-free survival and overall survival to be analysed?

We have dose intensities 40,80,120,160, and each dose intensity has different number of patients in it.
Thank you

Best Regards