Let me suggest that you try to understand the patient, not the pathology.
How did you feel when you found out?
How did you decide what to do?
Why did you choose this hospital? your doctor?
What helps you take your mind off of things?
Do you have a favorite vacation spot?
(look, you've managed to change the subject....)
HIPAA means that you can not share information that a patient gives you but it does not prohibit a patient from providing you with information. Some people enjoy talking about their illness, the tests, the treatments, their doctors, etc and if your job is to listen, you can certainly carry on a conversation. Some people have few, if any, visitors, and it is helpful for them to be able to go over things aloud with someone who is willing to listen.