['The Gleason index (GI) is related to several pathological endpoints in radical prostatectomy (RP) specimens, including the risk of extraprostatic disease (ED). The amount of tumour (TM) in core biopsy (CB) specimens also correlates with staging. The aim was to determine whether the sum of the relative statistical weights of GI and TM in CBs strengthens the prediction of ED in RPs.', "A series of 290 RPs and their previous respective CBs were reviewed. TM and the GI were blindly evaluated in CBs and statistically correlated with ED in RPs. A total of 60 (20.6%) RPs showed ED. The logistic regression model indicated that all cases with > 22 mm of cancer in CB showed ED in RP. All cases with a GI > 7 and > 12 mm of cancer in CB displayed ED. Finally, Pearson's chi2 revealed that 80% of cases with a GI > 7 and > or = 5 mm of cancer in CB showed ED in RP."] Is the combination of millimetres of cancer and Gleason index in core biopsy a predictor of extraprostatic disease?