Cancer final stages

Consider  a male client of yours, age 91, has a diagnosis of cancer, final stages and not able to surgically remove the tumor due to other health issues. His daughter who has medical power of attorney has stated she does not want her father to know his diagnosis since he has always had the fear he would die of cancer. In nursing school you have learned to be the patient advocate and provide information which would allow a client to make decisions for self. What would you do?