The impact of biopsy core length on the discrepancy in Gleason scores between biopsy and radical prostatectomy specimen

Objective

To assess the impact of the biopsy core length on the discrepancy in Gleason score between biopsy and radical prostatectomy specimens.

Patients and Methods

Retrospective analysis of clinical data from 247 patients who underwent transperineal prostate biopsy and radical prostatectomy of prostate cancer at our centre from 2022 to 2023. The clinical data included age, pre-biopsy prostate-specific antigen (PSA) levels, prostate volume, number of biopsy needles, number of positive biopsy needles, biopsy core length, biopsy Gleason score and post-radical prostatectomy Gleason score. Statistics were analysed by SPSS26.

Result

On histopathological examination, no changes in the Gleason score were observed in 127 (51.4%) patients, whereas the Gleason score was upgraded in 101 (40.9%) patients and downgraded in 19 (7.7%) patients at radical prostatectomy. Average biopsy core length for Gleason score upgraded on radical prostatectomy (44.3 %, n = 101) was 11.11 ± 1.34 mm compared to 11.88 ± 1.03 mm(p < 0.01)for Gleason score consistent(55.7 %, n = 127). The multivariate logistic regression analysis revealed a significant association between the biopsy core length (P < 0.01, OR = 0.556, 95%CI: 0.429–-0.722) and prostate volume (P < 0.05, OR = 0.982, 95%CI: 0.429–-0.722), with both factors being significantly correlated with radical prostatectomy Gleason score increase. Furthermore, these variables were identified as independent predictors of radical prostatectomy Gleason score increase and exhibited a negative correlation. The biopsy core length was evaluated using a receiver operating characteristic (ROC) curve, with a cutoff value of 11.4 mm for the accurate diagnosis of prostate cancer (AUC: 0.702, sensitivity: 75.6%, specificity 51.2%, P < 0.001).

Conclusion

The concordance between biopsy and radical prostatectomy may be improved with a longer biopsy core length. To enhance the consistency of Gleason scores between biopsy and radical specimens, it is recommended that the biopsy core length be at least 11.4 mm. Patients with a smaller prostate volume are at a higher risk of experiencing discordant pathological grades between biopsy and radical prostatectomy.