Effect of a novel bladder preservation therapy, BOAI-CDDP-radiation (OMC-regimen)

Abstract

We have developed a novel form of bladder preservation therapy [OMC (Osaka Medical College)-regimen] involving balloon-occluded-arterial-infusion (BOAI) of an 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. We previously reported that the OMC-regimen elicited a complete response (CR) in >90% of patients with organ confined tumors, while LN(+), T4 tumors and a non-UC histological type were statistically significant risk factors for treatment failure and patient survival. In this study, we investigated the effects of the OMC-regimen in patients with organ confined urothelial cancer tumors and the outcomes were compared to those with total cystectomy. Three hundred and one patients were assigned to receive either the OMC-regimen (n=162) or total cystectomy (n=139). 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 yielded 98.1% of clinical response; CR in 93.8% (152/162) of patients; PR in 4.3% (7/162). More than 96% of the CR patients (146/152) were alive with no evidence of recurrence after a mean follow-up of 166 (range 23-960) weeks. No patients suffered grade III toxicity; all patients successfully completed this therapy. The patient survival was significantly better compared to the cystectomy group; the overall 5-, 10- and 15-year survival rates were 87.3, 79.6 and 59.7%, respectively. Moreover, the 5-, 10- and 15-year bladder intact survival rates, the most important issue for bladder preservation therapy, were 85.7, 78.4 and 58.8%, respectively. In conclusion, the OMC-regimen is a useful bladder-preservation strategy, not only in those for whom cystectomy is indicated, but also in patients whose condition is not amenable to curative treatment and for whom palliation would otherwise seem the only option.