Diagnosis of isolated high-grade prostatic intra-epithelial neoplasia: proposal of a nomogram for the prediction of cancer detection at saturation re-biopsy

Abstract

Study Type--Diagnostic (case series). Level of Evidence 4. What's known on the subject? And what does the study add? Multifocality, age, PSA values, and biopsy protocols regarding the predictive value of high grade PIN have been discussed extensively in the literature. Our study developed for the first time a predictive nomogram that could be helpful for patient counselling and to guide the urologist to perform rPBX after an initial diagnosis of isolated HGPIN.

Objective: • To evaluate factors that may predict prostate cancer (PCa) detection after the initial diagnosis of high-grade prostatic intra-epithelial neoplasia (HGPIN) on prostate biopsy (PBx) with six to 24 random cores.

Patients and methods: • We retrospectively evaluated 262 patients submitted from 1998 to 2007 to prostate re-biopsy (rPBx) after an initial HGPIN diagnosis in tertiary academic centres. • HGPIN diagnosis was obtained on initial systematic PBx with six to 24 random cores. • All patients were re-biopsied with a 'saturation' rPBx with 20-26 cores, with a median time to rPBx of 12 months. • All slides were reviewed by expert uropathologists.

Results: • Plurifocal HGPIN (pHGPIN) was found in 115 patients and monofocal HGPIN (mHGPIN) was found in 147 patients. • In total, 108 and 154 patients, respectively, were submitted to >12-core initial PBx and ≤12-core initial PBx. • Overall PCa detection at rPBx was 31.7%. PSA level (7.7 vs 6.6 ng/mL; P= 0.031) and age (68 vs 64 years; P= 0.001) were significantly higher in patients with PCa at rPBx. • PCa detection was significantly higher in patients with a ≤12-core initial PBx than in those with a >12-core initial PBx (37.6% vs 23.1%; P= 0.01), as well as in patients with pHGPIN than in those with mHGPIN (40% vs 25.1%; P= 0.013). • At multivariable analysis, PSA level (P= 0.041; hazards ratio, HR, 1.08), age (P < 0.001; HR, 1.09), pHGPIN (P= 0.031; HR, 1.97) and ≤12-core initial PBx (P= 0.012; HR, 1.95) were independent predictors of PCa detection. • A nomogram including these four variables achieved 72% accuracy for predicting PCa detection after an initial HGPIN diagnosis.

Conclusions: • PCa detection on saturation rPBx after an initial diagnosis of HGPIN is significantly higher in patients with a ≤12-core initial PBx than those with a >12-core initial PBx and in patients with pHGPIN than in those with mHGPIN. • We developed a simple prognostic tool for the prediction of PCa detection in patients with initial HGPIN diagnosis who were undergoing saturation rPBx.