Spose Is 69 Yr Old Male Paraplegic Who Has Brown

Spose is 69 yr old male paraplegic who has brown sludge like urine with a thick skin like substance. Has used permanent catheter for last 8 to 10 years. Has been a paraplegic for 50 years. Docs don't seem interested but home care nurse very concerned.. Is this a symptom of cancer? Both his parents died in their 60s from different cancers. On throat and one liver.