We investigated the effect of balloon-occluded arterial infusion (BOAI) of anticancer agent (cisplatin/gemcitabine), used concomitantly with hemodialysis, which delivers an extremely high concentration of anticancer agent to the site of a tumor without systemic adverse effects, along with concurrent radiation (referred to as the OMC-regimen) in patients with advanced bladder cancer. One hundred and ninety-two patients were assigned to receive either the OMC-regimen (n=96) or total cystectomy (n=96). Patients in the OMC-regimen group who failed to achieve CR underwent cystectomy, or secondary BOAI with an increased amount of CDDP or gemcitabine (1600 mg). The OMC-regimen allowed >89% (69/77) of patients with locally invasive tumors to achieve CR [>70% (70/96) of all patients including those with T4 and N(+) disease]. Most (68/69) of the CR patients were still alive with no evidence of recurrence after a mean follow-up of 161 (range 12-805) weeks. The 5- and 15-year overall survival rates were 91.5 and 81.3% (vs. 59.8% and 40.1% for cystectomy, P<0.0001), respectively. No patients suffered Grade III or more severe toxicities. In contrast, at 5 and 15 years after surgery in the total cystectomy group, about 50 and 60% of patients had suffered disease progression or had died, respectively. The OMC-regimen, a new bladder-preservation strategy for patients with locally invasive bladder cancer, can be curative not only in patients for whom cystectomy is indicated, but also in patients whose condition is not amenable to curative treatment and for whom merely palliative therapy would otherwise seem the only option.