- 0Oct 5, '12 by olderthandirt51I work in the outpatient surgery dept of a large hospital. We have treated bladder CA pts with instillation of mitomycin but there is controversy over how the urine treated with mitomycin should be disposed of. Currently we flush it. I have a hard time with this considering they won't let us flush a pill. How does your facility handle this and would you be willing to send me a copy of your policy?