Expanded risk groups help determine which prostate radiotherapy sub-group may benefit from adjuvant androgen deprivation therapy

Matthew Beasley¹ , Scott G Williams² , Tom Pickles¹ and The BCCA Prostate Outcomes Unit¹

¹British Columbia Cancer Agency, Vancouver, Canada

²Peter MacCallum Cancer Centre, Melbourne, Australia

author email corresponding author email

Radiation Oncology 2008, 3:8doi:10.1186/1748-717X-3-8


Published:	18 April 2008

Abstract

Purpose

To assess whether an expanded (five level) risk stratification system can be used to identify the sub-group of intermediate risk patients with prostate cancer who benefit from combining androgen deprivation therapy (ADT) with external beam radiotherapy (EBRT).

Materials and methods

Using a previously validated 5-risk group schema, a prospective non-randomized data set of 1423 men treated at the British Columbia Cancer Agency was assessed for the primary end point of biochemical control (bNED) with the RTOG-ASTRO "Phoenix" definition (lowest PSA to date + 2 ng/mL), both with and without adjuvant ADT. The median follow-up was 5 years.

Results

There was no bNED benefit for ADT in the low or low intermediate groups but there was a statistically significant bNED benefit in the high intermediate, high and extreme risk groups. The 5-year bNED rates with and without ADT were 70% and 73% respectively for the low intermediate group (p = non-significant) and 72% and 58% respectively for the high intermediate group (p = 0.002).

Conclusion

There appears to be no advantage to ADT where the Gleason score is 6 or less and PSA is 15 or less. ADT is beneficial in patients treated to standard dose radiation with Gleason 6 disease and a PSA greater than 15 or where the Gleason score is 7 or higher.