The effect of short term neo-adjuvant androgen deprivation on erectile function in patients treated with external beam radiotherapy for localised prostate cancer: An analysis of the 4- versus 8-month randomised trial (Irish Clinical Oncology Research Group 97-01)

Abstract

Background and purposeErectile dysfunction is a common consequence of external beam radiotherapy (EBRT) for prostate cancer. The addition of neo-adjuvant androgen deprivation (NAD) has an indeterminate additive effect. We examined the long-term effect on erectile function (EF) of two durations (4months: arm 1 and 8months: arm 2) of NAD prior to radiation (RT) for patients with localised prostate cancer from the Irish Clinical Oncology Research Group (ICORG 97-01) 4- versus 8-month trial. In this study we aimed to (1) analyse the overall effect on EF of NAD in an EBRT population, (2) compare the probability of retained EF over time in an EBRT population treated with either 4 or 8months of NAD and (3) identify any variables such as risk group and age which may have an additive detrimental effect. This analysis provides unique long term follow up data. Materials and methodsFrom 1997 to 2001, 276 patients with adenocarcinoma of the prostate were randomised to 4 or 8months of NAD before RT. EF data were recorded at baseline and at each follow-up visit by physician directed questions, using a 4-point grading system. ResultsTwo hundred and thirty patients were included in the analysis of EF and were followed for a median of 80months. One hundred and forty-one patients had EF at baseline. Neo-adjuvant androgen deprivation in addition to radiation therapy caused a significant reduction in EF. The most significant reduction in EF happens within the first year. The median time to grade 3–4 EF toxicity was 14.6months, 17.6months in arm 1 and 13.7 in arm 2. Freedom from late EF toxicity did not differ significantly between arms, overall or at 5years (n=141). The cumulative probability of EF preservation at 5years was 28% (22–34) in arm 1 and 24% (19–30) in arm 2. Age was a significant predictor of post-treatment EF. ConclusionsThe first year post ADT and EBRT poses the greatest risk to sexual function and a continued decline may be expected. However, 26% of men can expect to retain sexual function at 5years.