Conversation: The conversation between human and AI assistant.
[|Human|] My father has metastatic prostate cancer, with tumours throughout the pelvis. He has a history of sciatica, and since the middle of the night, his foot has been numb, with pain all through leg, beginning around the thigh. What may the pain be from, and what may be the best thing for us to do?
[|AI|]  Hi, Thanks for writing in. Sorry to hear about your father having metastatic prostate cancer. Unfortunately when cancer prostate metastasizes to the lower back spine then it causes destruction of the bones in the lumbar spine. What happens is that the nerves originating from the lower segments of lumbar spine are compressed and there is pinching of the nerves due to bone destruction. These nerves also supply the legs and that is the reason he is having pain in the legs. Please get the lumbar spine assessed by the doctor and get prescription pain reliever medicines. He might also require highly potent opioid Chat Doctor.  Please do not worry.