Depends entirely on what the censoring rules are. E.g. if the censoring rule is "Censor at the last scheduled scan unless a later scan shows progression free or an event occurs within 2 week of the scheduled date" then you can get the following results (the below example is about 75 percentian, versus median, just because it takes fewer patients to explain):
2 patients, patient a has progression at 6.5 week scan, patient b misses their scan but dies at 7 weeks.
TTP results: at 5 weeks 100% KM curve and 2 patients on curve. At 6 weeks patient b is censored so there is only one patient on curve. At 6.5 weeks the patient a progresses and curve drops to zero. 75 percentian TTP is 6.5 weeks.
PFS results: as 5 weeks 100% KM curve and 2 patients on curve. At 6.5 weeks patient a progresses and curve drops to 50% with one patient left on curve. At 7 weeks curve drops to zero when patient b dies. 75 percentain PFS is 7.0 weeks.
There may be a standard for censoring - but I haven't discovered it yet and the rules I have seen have been pretty arcane and thus have lots of potential for small oddities.
>>A death in between progression assessments << The death will be excluded from TTP analysis if the patient died without any post-baseline imaging. If that death took place after the median TTP of 1.5 months, then the median PFS will be longer than that of TTP.