Final Analysis of RT+ADT versus ADT alone in locally advanced CaP

The March 2015 international urology journal club #urojc twitter discussion focused on a paper by Mason et al [1]. This article, published in the Journal of Clinical Oncology (Feb 2015), reports on the preplanned final analysis of the randomized trial of radiotherapy (RT) and androgen deprivation therapy (ADT) versus ADT alone in patients with locally advanced prostate cancer between 1995 and 2005.

The authors have previously reported on the survival benefits of RT added to ADT in this cohort of patients and the final analysis demonstrates a sustained longer-term survival outcomes of RT+ADT over a median follow-up of 8 years as compared to ADT alone.

As ever the discussion was lively with some polarized views. The feed commenced at 12:00pm PST on Sunday 1^st March 2015 for a 48-hour period. Initially debate focused on staging and the under-reporting of DRE findings:

Which was perhaps addressed by issues during the screening process…

Despite this, other aspects of staging were discussed, particularly the methods for node staging:

For N staging, the authors included either a clinical assessment (70.5% of patients), Imaging (8.5%) or surgical dissection (2.4%). Meanwhile, the accuracy of ‘clinical’ nodal staging was questioned.

Consideration of the patient inclusion criteria was followed by a discussion over the use of ADT in this patient cohort

In this context, ADT consisted of either BSO or lifelong LHRH agonists

However, the question was asked of ADT in addition to RT ‘is lifelong ADT appropriate?’

While for high-risk disease, evidence suggests that long-term (2-3 years) ADT should be used following RT [2, 3], for intermediate risk cancers, 8 weeks of adjuvant ADT remains the standard of care as highlighted in the recent RTOG 9910 data [4].

The rationale behind RT and ADT was noted:

While the results of the study came as no shock to some:

The addition of RT to ADT significantly improved OS and DSS. The study reports that ‘there was no evidence of any differences in deaths from other causes’, however, the issue of secondary malignancies with RT was ‘highlighted’: