Presentation Authors: Gill Inderbir*, Los Angeles, CA, Abdel Azzouzi, Angers, France, Mark Emberton, London, United Kingdom, Billy Amzal, Jie Meng, Paris, France, Peter Scardino, New York, NY
Introduction: Functional outcomes after VTP, AS or RP for localized prostate cancer differ. We evaluated urinary incontinence (UI) and erectile dysfunction (ED) from 2 prospective randomized controlled trials (RCTs), including the impact of conversion to radical therapy (RT) in men undergoing VTP and AS by morbidity modelling.
Methods: Toxicity data from PCM301, a RCT comparing VTP and AS was correlated with toxicity profiles from ProtecT, a RCT comparing active monitoring, RP and external-beam radiotherapy. In both RCTs, toxicity was prospectively defined for each treatment strategy. ED and UI rates after VTP and AS were obtained from the 7-year extended follow-up (FU) arm of PCM301, using MedDRA terms to define adverse events (Grade II or higher). From the RP and RT arms of ProtecT, the time-dependent rates of ED and UI were used for RP, as well as for PCM301 patients converting to RT after VTP or AS. Area under the curve analysis demonstrated the ratio of time integrated toxicity exposure.
Results: From PCM301, a total of 413 subjects were included (VTP 206, AS 207). Percentage of patients with ED and UI, as a function of time, is presented in panels A and B, respectively. The VTP, AS and RP area under the curves to 60 months for ED are 5.87, 8.55 and 28.21, respectively. The ratio of the areas under the curves for VTP/AS and VTP/RP are 0.69 (95%CI: 0.04,0.91) and 0.25 (95%CI: 0.18,0.35), respectively. For UI, the areas under the curves were 1.49, 3.93 and 12.18 for VTP, AS and RP, respectively yielding ratios of 0.38 (95%CI: 0.25,0.53) and 0.12 (95%CI: 0.09,0.16) for VTP/AS and VTP/RP, respectively.
Conclusions: When conversion to RT is taken into account, men undergoing VTP as their initial therapy suffered lesser ED and UI compared to those who started with either RP or AS. This superior toxicity profile of VTP can largely be attributed to its lower rate of conversion to RT.