P2-141 - Exclusion of stage IV transitional cell carcinoma of the bladder with prior cancers from clinical trials. Is it valid?

Abstract

Background: Most clinical trials on stage IV transitional cell carcinoma of the bladder (TCC) exclude stage IV TCC cases with any history of a prior malignancy. However, no evidence is present to support this practice. The aim of our study is investigate the effects of a prior malignancy on survival outcomes of the stage IV TCC, and to question the benefits of including/excluding patients with prior malignancies in the clinical trials. Methods: The Surveillance, Epidemiology, and End Results (SEER) Program was accessed to review patients with stage IV TCC cases diagnosed between 1973 and 2014. We calculated overall and bladder cancer-specific survival of patients with/without prior cancers using unadjusted Kaplan-Meier and cox regression models. Results: We reviewed 8,275 patients with stage IV TCC, of which 798 had a history of a prior cancer. Overall survival of patients with prior cancers was not significantly difference from patients without prior cancers (P=.204). Adjustment for sex, age, race, marital status, grade of TCC, and undergoing surgery, showed similar results (HR = 1.033, 95%CI= .949-1.125, P=.452). When patients with prior cancers were divided according to the site of the prior cancer or the latency groups between the two diagnoses, none of site and latency groups showed significant difference in overall survival from patients with no prior cancers. Conclusion: Our study showed that a history of a prior malignancy had no significant effect on the survival of stage IV TCC. Based on these results, we recommend the reconsideration of clinical trials eligibility criteria regarding patients with prior malignancies. However, prior exposure to systemic treatment may still be needed to be taken into consideration. Further and more detailed studies are required to determine the best approaches.