Danny, My family's prayers are with you and your wife. The Dr. was definitely wrong in assumimg that your wife has cancer just because of blood in her urine without any further testing or analysis. Kidney infection, bladder infection, kidney stones as mentioned by Frank above are all possible sources/causes of blood in the urine, and that is just to name a few. It ticks me off that ALOT of Dr's. pass off the worst case scenario first to a patient without any thought to the ramifications that it can have on the psyche of a person! I guess thier mentality is that if they give you the worst case scenario, then something other than the worst case will just be a blessing. That is a shame.
Anyway, my heart and prayers are with you regardless of the cause! God Bless you and your wife in your time of need Danny! Sorry for rambling.