Mr. Fox has been receiving treatment for lung cancer for two…

Mr. Fox has been receiving treatment for lung cancer for two weeks.  He normally comes in alone, but today, his wife is off work and decides to accompany him to his treatment.  As you are walking by, Mrs. Fox stops you in the hall and asks what side effects her husband may experience from his radiation treatments.  How do you respond and what, if any, ethical principles apply to this situation?