A Study On The Correlation Between Needle Biopsy And Radical Prostatectomy Specimen

Objective:To study the concordance of Gleason score and tumor laterality between needle biopsy and radical prostatectomy specimen, and determine needle biopsy combined other preoperative factors associated with surgical margin status. The study ultimately aims to evaluate the prediction of prostate biopsy in pathological grading, distribution, range and risk of tumor progression.Methods:The retrospective study recruited260patients with prostate cancer who had been diagnosed by transrectal ultrasound-guided prostate biopsy, and eventually treated with laparoscopic radical prostatectomy between January2006and June2012at our hospital. Kappa test was used to analyze the concordance of Gleason score.χ2test were used to evaluate the possible statistical difference of tumor laterality. To access the impact of biopsy factors on positive surgical margin, and multivariate logistic regression analysis was performed in order to estimate the relative importance of independent variables in predicting the risk of positive surgical margins.Results:The mean Gleason score in needle biopsy was6.99±0.9, while the mean Gleason score in radical prostatectomy specimen was7.1±0.9, the difference was of no statistically significance(P=0.603). Kappa test indicated a good agreement of Gleason score between these two cohorts (Kappa value=0.603). Of153patients with unilateral tumor in needle biopsy,83(54.3%) had bilateral tumor on final pathology, the unilateral positive biopsy were significantly different from final pathology(P<0.001). Errors were of significant difference in different prostate volume cohorts(x2=21.393, P<0.001), while no significant difference in different age cohorts(χ2=1.721, P=0.423).The overall rate of positive surgical margins was37.7%(98/260). At the univariate analysis, age(P=0.423), prostate volume(P=0.328) and serum PSA(P=0.788) were not significantly correlated with the risk of positive surgical margins. Biopsy Gleason score, percentage of tumor in biopsy, number of positive cores, perineural invasion and biopsy tumor laterality significantly correlated with the risk of positive surgical margins(P<0.001). At the multivariable logistic regression analysis, biopsy Gleason score (P=0.007, odds ratio,2.269;95%confidence interval,1.248to4.127) and perineural invasion (P<0.001, odds ratio,16.299;95%confidence interval,7.936to33.475) maintained their significance and were independent predictors of positive surgical margins. These two independent factors were also of significant difference between intracapsular and extracapsular cohorts (P<0.001).Conclusion:In this study, transrectal ultrasound-guided12cores prostate biopsy shows predictive value on Gleason score in radical prostatectomy specimen. Biopsy tumor laterality is not suitable for predicting tumor distribution. Biopsy Gleason score and perineural invasion in biopsy specimen were independent predictors of positive surgical margins in patients with clinically localized prostate cancer treated by laparoscopic radical prostatectomy. These two factors are also related to increased likelihood of extracapsular extension.