Hi!! I believe u might have got d answer for ur queries regarding ur father histo reports.
usually doc who has done d surgery has to instruct d patient how well the histo reports were and what kind of checkups required.It may required some times to keep the patient under observation(normal visits to doc) for enquiring how well he/she is keeping..During these checkups doc will observe if there are any recurrances/fishy matters.
Then regarding the food, its highly required to have hygenic food and as much fruits as possible. I have a document for diet for cancer avoidance which i have prepared/collected from google after my mother hit with mouth cancer.
If u want i can share it with u..
God helps you.Cheerup. Bye..
Mahan