The clinical significance of biochemical failure in the first 2 years in patients treated with neo-adjuvant androgen deprivation and radiotherapy for prostate cancer

Introduction: Biochemical failure in the first 2 years after radical prostatectomy confers an adverse prognosis compared to later biochemical relapse. This supplementary analysis of the Irish Clinical Oncology Research Group Trial 97-01 assess if this is also the case for patients managed with neo-adjuvant hormonal treatment and radiotherapy. Methods: The Irish Clinical Oncology Group initiated a prospective randomised trial (ICORG 97-01) that compared 4 versus 8 months of neo-adjuvant androgen deprivation therapy (NADT) for patients treated with 3D conformal radiotherapy (RT) for prostate cancer. This supplementary study describes a Cox regression analysis of data from 253 participants in that trial. Results: In patients with EBF (early biochemical failure) i.e., within 2 years, median survival time after completion of radiotherapy is 8.9 years, compared to 12.6 years in patients with LBF (late biochemical failure). Prostate cancer specific mortality risk was higher in the EBF cohort (Hazard ration (HR)= 6.75, 95% Confidence Interval (C.I.)= 3.1–14.7, P-value < 0.0001) compared to those with LBF. The risk of EBF was higher for patients with stage T2c-T4 disease compared those with stage T1-T2b disease (HR= 2.93, 95% CI= 1.30–6.58, P-value= 0.009). On multivariate analysis the estimated hazard of risk of EBF increased 1.02 fold for each increase of 1ng/mL in initial PSA. In the multi-variate model Gleason score also predicted EBF. Conclusion: Patients with prostate cancer treated with neo-adjuvant androgen deprivation therapy and radiation therapy that develop EBF have a shorter median duration of prostate cancer specific mortality (PCSS) than those with LBF.