Proportion of cores with the highest Gleason grade group among positive cores on prostate biopsy: does this affect the probability of upgrading or downgrading?

Abstract

Purpose: This study assessed the ability to predict the probability of pathologic upgrading or downgrading based on the proportion of cores with the highest Gleason grade on prostate biopsy.

Materials and methods: From 2002–2017, 494 patients with multiple positive cores on prostate biopsy who underwent radical prostatectomy were included for the analysis. The proportion of cores with the highest Gleason grade group among positive cores was calculated and patients were divided into three groups based on the proportion (≤33% vs >33% and ≤67% vs >67%).

Results: Tumor characteristics, including PSA level, biopsy Gleason grade, preoperative MR imaging, pathologic grade, pathologic stage and tumor volume, were worse in patients with a highest Gleason grade proportion, ≤33%. Upgrading (5.6% vs 15.0% vs 39.4%, p < 0.001) was more common in patients with a higher highest Gleason grade proportion, while downgrading (51.7% vs 35.3% vs 7.2, p < 0.001) was more common in patients with a lower highest Gleason grade proportion. On multivariate analysis, the highest Gleason grade proportion was a significant predictor for upgrading and downgrading in addition to other clinical variables. The areas under the curve for models predicting upgrading (0.784 vs 0.768, p = 0.009) and downgrading (0.746 vs 0.717, p = 0.017), which incorporating the highest Gleason grade proportion, were significantly higher than models without the highest Gleason grade proportion.

Conclusions: The proportion of cores with the highest Gleason grade is a readily available novel parameter for calculating the probability of upgrading or downgrading.

Keywords:

• Biopsy
• neoplasm grading
• pathology
• prostatectomy
• prostatic neoplasms

Informed consent

Waived by IRB.

Disclosure statement

The authors report that they have no competing interests.

Data availability

The datasets generated and/or analysed during the current study are not publicly available due to the institutional policy, but are available from the corresponding author on reasonable request.