Oral & Poster Presentation – Clinical Abstracts Archive

UK & Ireland Prostate Brachytherapy Conference 2016

Abstract number 6

Predictors of survival and causes of death following low-dose rate brachytherapy and robotic-assisted laparoscopic prostatectomy in low-and intermediate-risk prostate cancer: a UK Cancer Registry-linked study 

Yamamoto H*; Goggins A* ; Morris S*; Challacombe B*; Beaney R*; Popert R* 
*Guy’s & St. Thomas’ NHS Foundation Trust, London 

AIMS/INTRODUCTION: Comparative studies of prostate brachytherapy and radical prostatectomy have focussed on biochemical relapse rather than hard clinical endpoints such as overall survival (OS) and prostate cancer-specific survival (PCSS). Here, we assessed the two treatments by risk-adjusted OS and PCSS in patients with low- and intermediate-risk prostate cancer. 

MATERIALS/METHODS: Patients were included if treated for organ-confined prostate cancer between 2003-2013 with low-dose-rate prostate brachytherapy (LDR-PB) or robotic-assisted laparoscopic prostatectomy (RALP) as monotherapy. Patients with high-risk disease, prior prostate cancer treatment, or planned adjuvant therapy, were excluded. Data on PSA, biopsy-derived maximum Gleason score, age, ethnicity, treatment date, modified Charlson comorbidity score, mode of diagnostic biopsy (transrectal/transperineal), and socioeconomic status were collected using electronic records. Vital status was retrieved from the National Cancer Registry. Statistical methods included Kaplan-Meier and Cox regression analyses. 

RESULTS: 1392 patients received either LDR-PB (n=408) or RALP (n=984) as monotherapy. Median follow up was 57.8mths (range 1-136mths). 2 deaths occurred due to prostate cancer. 5-year OS and PCSS for the cohort was 96.9%, and 100%, respectively. OS and PCSS did not differ significantly between LDR-PB and RALP by multivariate regression analysis (HR 0.92, 95% C.I. 0.45-1.89, p=0.82). Comorbidity score ≥1 (p=0.005) and ethnicity (p=0.01) were identified as being independent predictors of lower OS. Hazard of death increased 2.4- and 3.4-fold with 1, or ≥2 comorbidity points. 

CONCLUSION: Prostate cancer mortality risk following treatment for low- and intermediate-risk cancer is very low in the first 5 years following treatment by RALP or LDR-PB. Comorbidity is an important predictor of early death which can be reliably assessed and risk-stratified using a modified Charlson scoring system. Our data adds to the limited literature on comparative outcomes following prostate brachytherapy and radical prostatectomy.