New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia.

The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.

Impact of Cribriform Pattern and Intraductal Carcinoma on Gleason 7 Prostate Cancer Treated with External Beam Radiotherapy.

PURPOSE: We assessed the impact of cribriform pattern and/or intraductal carcinoma on Gleason 7 prostate cancer treated with external beam radiotherapy. METHODS: We evaluated men with Gleason 7 (Grade Groups 2 and 3) prostate cancer treated with dose escalated external beam radiotherapy with or without androgen deprivation. We reviewed biopsies for the presence of cribriform pattern and/or intraductal carcinoma. Study end points included biochemical recurrence-free, distant metastasis-free and disease specific survival. RESULTS: In the 237 patients median followup was 117 months (range 3 to 236). According to National Comprehensive Cancer Network® risk groups 24% of patients were at favorable intermediate risk, 53% were at unfavorable intermediate risk and 23% were at high risk. The rate of cribriform pattern without intraductal carcinoma, cribriform pattern with intraductal carcinoma, intraductal carcinoma without cribriform pattern and none of these morphologies was 36%, 13%, 0% and 51%, respectively. On multivariable analysis cribriform pattern with intraductal carcinoma (HR 4.22, 95% CI 2.08-8.53, p <0.0001), prostate specific antigen 10 to 20 ng/ml (HR 1.97, 95% CI 1.03-3.79, p=0.04) and prostate specific antigen greater than 20 ng/ml (HR 2.26, 95% CI 1.21-4.23, p=0.01) were associated with worse biochemical recurrence-free survival. On multivariable analysis only cribriform pattern with intraductal carcinoma was associated with inferior distant metastasis-free survival (HR 4.18, 95% CI 1.43-12.28, p=0.01) and disease specific survival (HR 14.26, 95% CI 2.75-74.04, p=0.0016). Factors associated with cribriform pattern with or without intraductal carcinoma included Grade Group 3, high risk group and 50% or more positive biopsy cores. When stratified by neither morphology present, cribriform pattern without intraductal carcinoma and cribriform pattern with intraductal carcinoma the differences in biochemical recurrence-free, distant metastasis-free and disease specific survival were statistically significant (p=0.00042, p=0.017 and p <0.0001, respectively). CONCLUSIONS: Cribriform pattern with intraductal carcinoma was associated with adverse outcomes in men with Gleason 7 prostate cancer treated with external beam radiotherapy while cribriform pattern without intraductal carcinoma was not so associated. Future studies may benefit from dichotomizing these 2 histological entities.

Genomic Scores are Independent of Disease Volume in Men with Favorable Risk Prostate Cancer: Implications for Choosing Men for Active Surveillance.

PURPOSE: We sought to determine whether disease volume at prostate biopsy would correlate with genomic scores among men with favorable risk prostate cancer. MATERIALS AND METHODS: We identified all men with NCCN® (National Comprehensive Cancer Network®) very low and low risk disease who underwent Oncotype DX® prostate testing at our institution from 2013 to 2016. Disease volume was characterized as the percent of positive cores, the number of cores with greater than 50% involvement, the largest involvement of any single core and prostate specific antigen density. Nonparametric testing was performed to compare the median Genomic Prostate Score™ and the likelihood of favorable pathology findings between quartiles of disease volume. RESULTS: We identified 112 (37.8%) and 184 men (62.2%) at NCCN very low and low risk, respectively. Median scores did not differ significantly between disease volume quartiles (all p >0.05). However, the median likelihood of favorable pathology findings statistically differed between volume quartiles (all <0.05). Seven of the 105 men (6.3%) with very low risk disease were reclassified at low risk and 13 of 181 (7.2%) with low risk disease were reclassified at intermediate risk. Genomic disease reclassification did not depend on biopsy tumor volume. CONCLUSIONS: In patients with NCCN very low and low risk prostate cancer genomic scores did not demonstrate meaningfully significant differences by volume based on clinically established cutoff points. Moreover, genomic scores identified and reclassified men with higher risk disease despite generally acceptable surveillance characteristics in this group according to grade and volume. This suggests that in patients at low risk the tumor biological potential measured by genomics rather than by volume should inform decisions on active surveillance candidacy.

Decipher Genomic Classifier Measured on Prostate Biopsy Predicts Metastasis Risk.

OBJECTIVES: To evaluate the ability of the Decipher genomic classifier in predicting metastasis from analysis of prostate needle biopsy diagnostic tumor tissue specimens. MATERIALS AND METHODS: Fifty-seven patients with available biopsy specimens were identified from a cohort of 169 men treated with radical prostatectomy in a previously reported Decipher validation study at Cleveland Clinic. A Cox multivariable proportional hazards model and survival C-index were used to evaluate the performance of Decipher. RESULTS: With a median follow up of 8 years, 8 patients metastasized and 3 died of prostate cancer. The Decipher plus National Comprehensive Cancer Network (NCCN) model had an improved C-index of 0.88 (95% confidence interval [CI] 0.77-0.96) compared to NCCN alone (C-index 0.75, 95% CI 0.64-0.87). On multivariable analysis, Decipher was the only significant predictor of metastasis when adjusting for age, preoperative prostate-specific antigen and biopsy Gleason score (Decipher hazard ratio per 10% increase 1.72, 95% CI 1.07-2.81, P = .02). CONCLUSION: Biopsy Decipher predicted the risk of metastasis at 10 years post radical prostatectomy. While further validation is required on larger cohorts, preoperative knowledge of Decipher risk derived from biopsy could indicate the need for multimodality therapy and help set patient expectations of therapeutic burden.

Development and clinical validation of an in situ biopsy-based multimarker assay for risk stratification in prostate cancer.

PURPOSE: Prostate cancer aggressiveness and appropriate therapy are routinely determined following biopsy sampling. Current clinical and pathologic parameters are insufficient for accurate risk prediction leading primarily to overtreatment and also missed opportunities for curative therapy. EXPERIMENTAL DESIGN: An 8-biomarker proteomic assay for intact tissue biopsies predictive of prostate pathology was defined in a study of 381 patient biopsies with matched prostatectomy specimens. A second blinded study of 276 cases validated this assay's ability to distinguish "favorable" versus "nonfavorable" pathology independently and relative to current risk classification systems National Comprehensive Cancer Network (NCCN and D'Amico). RESULTS: A favorable biomarker risk score of ≤0.33, and a nonfavorable risk score of >0.80 (possible range between 0 and 1) were defined on "false-negative" and "false-positive" rates of 10% and 5%, respectively. At a risk score ≤0.33, predictive values for favorable pathology in very low-risk and low-risk NCCN and low-risk D'Amico groups were 95%, 81.5%, and 87.2%, respectively, higher than for these current risk classification groups themselves (80.3%, 63.8%, and 70.6%, respectively). The predictive value for nonfavorable pathology was 76.9% at biomarker risk scores >0.8 across all risk groups. Increased biomarker risk scores correlated with decreased frequency of favorable cases across all risk groups. The validation study met its two coprimary endpoints, separating favorable from nonfavorable pathology (AUC, 0.68; P < 0.0001; OR, 20.9) and GS-6 versus non-GS-6 pathology (AUC, 0.65; P < 0.0001; OR, 12.95). CONCLUSIONS: The 8-biomarker assay provided individualized, independent prognostic information relative to current risk stratification systems, and may improve the precision of clinical decision making following prostate biopsy.

Ductal adenocarcinoma of the prostate diagnosed on transurethral biopsy or resection is not always indicative of aggressive disease: implications for clinical management.

OBJECTIVE: To report the clinicopathological characteristics of 23 cases of ductal adenocarcinoma of the prostate (DCP) and discuss the implications for clinical management, as DCP is considered an aggressive subtype of prostate adenocarcinoma (PA). PATIENTS AND METHODS: The presence of DCP in transrectal ultrasonography-guided prostate biopsy (TRUSB) is associated with adverse pathological findings at radical prostatectomy (RP) and clinical outcomes, and the significance of detecting DCP initially in transurethral biopsy (UB) or transurethral resection (TURP) in the present era of screening with prostate-specific antigen (PSA) is unclear. The study included 23 cases of pure DCP without acinar PA diagnosed on UB or TURP. Demographic information, serum PSA level, follow-up surgical procedures (RP, TURP or TRUSB) and outcome data were collected. RESULTS: The mean age of the men was 67.5 years and the mean PSA level before the procedure was 12.5 ng/mL; 14 cases were detected on UB and nine were diagnosed on TURP. The mean (range) follow-up was 4 (1-23) months after the initial procedure. In all, 21 (89%) patients had DCP or PA in follow-up procedures. Two (11%) patients had no residual cancer, one on RP and the other on two repeat TURPs. DCP or PA was found in 12 RP cases; four patients had Gleason score 7 PA, three of which were organ-confined, and eight had Gleason score > or = 8 PA. Extraprostatic extension, seminal vesicle invasion and regional lymph node metastasis were present in seven, six and two cases, respectively. CONCLUSIONS: Most DCP diagnosed on UB or TURP in this contemporary series was associated with aggressive PA, but a subset presented as a small periurethral tumour with no concomitant acinar PA, and was eradicated by the initial biopsy/TURP alone. We recommend that patients with a diagnosis of DCP on UB or TURP undergo follow-up TURP and TRUSB before radical surgery is offered.