Can gi cancers cause strong urine odor?

Not likely: That would be a new one i've never heard before. Things that commonly cause urine to smell include certain foods (asparagus and garlic) as well as infection. Also a fistula between the bladder and colon could cause this. See your doctor.

Well...: "gi cancer" is a very vague term. If someone has pancreatic, liver, or biliary duct cancer causing bile duct obstruction and jaundice, the urine would turn dark, like coca cola in color (choluria) and may have a funky smell but there would be many other issues going on that would suggest a diagnosis if cancer.