Table 3. Gleason sums in hormone-resistant prostate cancer tumours with and without AR amplification.

	AR normal (38 cases)	AR amplified (10 cases)	P-value
Gleason sum ⩽6	23% (9/38)	0% (0/10)
Gleason sum=7	32% (12/38)	10% (1/10)
Gleason sum ⩾8	45% (17/38)	90% (9/10)	0.423

AR amplification=AR : X ratio greater than 1.5, AR normal=AR : X ratio within normal range. The Mann–Whitney test was used to establish if there was a significant difference in Gleason sum in tumours with or without AR amplification.