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OBJECTIVES: To assess the concordance between biopsy and radical prostatectomy (RP) specimens using the 2005 Gleason score (GS) and the International Society of Urological Pathology (ISUP) 2014/World Health Organization 2016 modified system, accounting for the introduction of transperineal biopsy and pre-biopsy multiparametric magnetic resonance imaging (mpMRI). PATIENTS AND METHODS: Between 2002 and 2019, we identified 2431 patients with paired biopsy and RP histopathology from a prospectively recorded and maintained prostate cancer database. Biopsy specimens were graded according to the 2005 GS or ISUP 2014 modified system, according to the year of diagnosis. Multivariable logistic regression analysis was conducted to retrospectively assess the impact of prostate-specific antigen (PSA), PSA density, age, pre-biopsy mpMRI, and biopsy method, on the rate of upgraded disease. The kappa coefficient was used to establish the degree of change in concordance between groups. RESULTS: Overall, 24% of patients had upgraded disease and 8% of patients had downgraded disease when using the modified ISUP 2014 criteria. Agreement in the updated ISUP 2014 cohort was 68%, compared with 55% in the 2005 GS group, which was validated by a kappa coefficient that was good (k = 0.5 ± 0.4) and poor (k = 0.3 ± 0.1), respectively. In multivariable models, a change in grading system independently improved overall disease concordance (P = 0.02), and there were no other co-segregated patient or pathological factors such as PSA, total number of cores, maximum cancer length, biopsy route or the use of mpMRI that impacted this finding. CONCLUSION: The 2014 ISUP modifed system improves overall concordance between biopsy and surgical specimens, and thus allows more accurate prognostication and management in high-grade disease, independent of more extensive prostate sampling and the use of mpMRI.

OBJECTIVE: To compare the accuracy of 68 gallium prostate-specific membrane antigen positron emission tomography/computed tomography (68 Ga-PSMA PET/CT) with multiparametric MRI (mpMRI) in detecting and localising primary prostate cancer when compared with radical prostatectomy (RP) specimen pathology. PATIENTS AND METHODS: Retrospective review of men who underwent 68 Ga-PSMA PET/CT and mpMRI for primary prostate cancer before RP across four centres between 2015 and 2018. Patients undergoing imaging for recurrent disease or before non-surgical treatment were excluded. We defined pathological index tumour as the lesion with highest International Society of Urological Pathology Grade Group (GG) on RP specimen pathology. Our primary outcomes were rates of accurate detection and localisation of RP specimen pathology index tumour using 68 Ga-PSMA PET/CT or mpMRI. We defined tumour detection as imaging lesion corresponding with RP specimen tumour on any imaging plane, and localisation as imaging lesion matching RP specimen index tumour in all sagittal, axial, and coronal planes. Secondary outcomes included localisation of clinically significant and transition zone (TZ) index tumours. We defined clinically significant disease as GG 3-5. We used descriptive statistics and the Mann-Whitney U-test to define and compare demographic and pathological characteristics between detected, missed and localised tumours using either imaging modality. We used the McNemar test to compare detection and localisation rates using 68 Ga-PSMA PET/CT and mpMRI. RESULTS: In all, 205 men were included in our analysis, including 133 with clinically significant disease. There was no significant difference between 68 Ga-PSMA PET/CT and mpMRI in the detection of any tumour (94% vs 95%, P > 0.9). There was also no significant difference between localisation of all index tumours (91% vs 89%, P = 0.47), clinically significant index tumours (96% vs 91%, P = 0.15) or TZ tumours (85% vs 80%, P > 0.9) using 68 Ga-PSMA PET/CT and mpMRI. Limitations include retrospective study design and non-central review of imaging and pathology. CONCLUSION: We found no significant difference in the detection or localisation of primary prostate cancer between 68 Ga-PSMA PET/CT and mpMRI. Further prospective studies are required to evaluate a combined PET/MRI model in minimising tumours missed by either modality.

OBJECTIVE To evaluate the significance of routinely reported 'equivocal' lymphovascular invasion (LVI) in prostatectomy specimens of patients with clinically localized prostate cancer. MATERIALS AND METHODS Prospectively collected data from men who underwent prostatectomy for clinically localized prostate cancer were retrospectively reviewed. Rates of adverse pathological features and biochemical recurrence (BCR) were compared between tumours positive, negative or 'equivocal' for LVI. Multivariable Cox regression analysis was performed to identify independent predictors of BCR. RESULTS Of 1 310 consecutive cases, LVI was present definitively in 82 (6.3%) and equivocally in 43 (3.3%) cases. Similar to definitive LVI, equivocal LVI was significantly associated with other adverse pathological features, including advanced stage, higher Gleason grade and positive surgical margins. BCR occurred more frequently in patients with tumours that were equivocal (61%) or positive for LVI (71%) than in patients with negative results (14.7%). In addition, patients with both definitive and equivocal LVI had a significantly shorter BCR-free survival time compared with those with negative LVI. Multivariable Cox regression analysis indicated that the presence of either definitive or equivocal LVI were independent predictors of disease recurrence (hazard ratio [HR] 3.32, 95% confidence interval [CI] 2.3-4.8; P

Objective To determine the relevance of intraductal carcinoma of the prostate (IDC-P) in advanced prostate cancer by first examining whether IDC-P was originally present in patients who later developed advanced prostate cancer and then using patient-derived xenografts (PDXs) to investigate the response of IDC-P to androgen deprivation therapy (ADT). Materials and methods We conducted a retrospective pathology review of IDC-P in primary prostate biopsy or surgery specimens from 38 men who subsequently developed advanced prostate cancer. Overall survival was calculated using the Kaplan-Meier method. To demonstrate the response of IDC-P to ADT, we established PDXs from seven patients with familial and/or high-risk sporadic prostate cancer. After castration and testosterone restoration of host mice, we measured the volume and proliferation of IDC-P within PDX grafts. Results We found that IDC-P was a prominent feature in the primary prostate specimens, present in 63% of specimens and often co-existing with poorly differentiated adenocarcinoma. Overall survival was similar in patients with or without IDC-P. In the PDXs from all seven patients, IDC-P was identified and present at a similar volume to adenocarcinoma. Residual IDC-P lesions persisted after host castration and, similar to castrate-tolerant adenocarcinoma, testosterone restoration led to tumour regeneration. Conclusion The study showed that IDC-P is prevalent in aggressive prostate cancer and contains cells that can withstand androgen deprivation. Thus, IDC-P appears functionally relevant in advanced prostate cancer. The presence of IDC-P may be a trigger to develop innovative clinical management plans.