Mariam,
I don't want the oveload to become too unmanageable but I need to add my 2 cents worth.
1) I agree with Jerry, the cancer, radiation and chemo are not a good reason to remove teeth that otherwise would not need to be removed.
2) what instrument does he play?
3) I do assess ments pre treatment for the local oncologists in my area and try in all patients to say any serviceable teeth. If you read about the eating difficulties many of the OCF members are having teeth become the golden fleece.
4) Many time extracting teeth delay proposed chemo and radiation therapy due to the fact that they take longer to heal when the immune system is already challenged. The risk of infection and other problems increases drastically if extraction sockets are not completely healed prior to commencing chemo and radiation.
5) At 71 even if your father was not about to go throught the treatment he would find the task of learning to eat with prosthtic teeth a challenge and with the treatment even more difficult. One of the issues later on is nutrition and we need to be able to chew food to start the digestive process.

Just a few thoughts.
E-mail me any time.

My thoughts and prayers are with you and your father.

Mike