['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).', '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.', '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).'] Do expanded risk groups help determine which prostate radiotherapy sub-group may benefit from adjuvant androgen deprivation therapy?