I see what you mean, you can't be mad, but maybe disappointed. It just makes me angry how we sometimes have to be our own doctor.
I posted a question similar to yours in August about my dad and the responses I got were that it depends on the agressiveness and grade of the tumor. I would assume you have those pathology reports somewhere? My dad's was very low grade, so it is slow growing, a few months would not have made any difference. I also know from the med mal defense work my firm does that a few months often would not matter unless it is an ultra fast grade.
Maybe ask your oncologist what he thinks? I asked everyone on my dad's team just out of "curiousity" and they all also said it just depends, but his was too low grade to have made a difference in two months.