I have had 4 clean cystoscopy, including my last one on October 10th. I am now 2 years post diagnosis. After receiving the all clean, and booking my next check for 6 months I received a call from my uro that my urine drop showed no cancer cells. but was deemed abnormal, and I have to do another urine test in 6 weeks. Is this a sign of possible reacurrence. even with a clean cysto? How reliable are these urine cultures, given that they are analyzing pee from a cup.