Hi My Friend Is Age 71 And Has Stage 4

Hi my friend is age 71 and has stage 4 prostate cancer and still wants to eat his red meats both barbequed and pan fried. How have stressed to him to stay away from red meats and eat more fish and white meats explaining that he red meats not helping his body to fight his cancer. He is on hormone therapy from shot and pill form. His tumor factors had dropped from 5700 to 2900 within 2 months of treatment
He is eating some white meat but want to eat red meat every few days. Please help Thanks William