No diagnosis
Step-by-step explanation:
The 60-year-old man has already been diagnosed with prostate cancer. The symptoms which he is suffering like pain is due to the bony metastasis and side effects caused by the antiandrogenic medications taken to treat his cancer.
Antiandrogenic drugs work against the male hormone testosterone and cause serious side effects like infertility, hot flashes, etc. It also causes osteoporosis and makes the bones weak which leads to pain in the bones and joints.
In the given case, cancer has metastasized to his bones and this factor along with osteoporosis will make his bones and joints weak and painful.
He is also not anxious about the pain and is stoical about it. So the main diagnosis is prostate cancer and the pain is both a symptom and a side effect.