Histopathologic and Molecular Characterization of IDH-Mutant Prostatic Adenocarcinoma.

Gain-of-function isocitrate dehydrogenase (IDH) mutations are pathogenically significant in many tumor types and are actionable in cholangiocarcinoma, low-grade glioma, and acute myeloid leukemia. Rare IDH mutations have been described in prostatic adenocarcinoma (PCa). Recent publications have suggested that psammomatous calcifications in PCa are associated with IDH1 mutations. In this retrospective study, we queried our institutional clinical sequencing database (cohort 1), and previously published PCa data sets in cBioPortal (cohort 2). Samples were stratified based on oncogenic hotspot IDH mutations at IDH1 R132 and IDH2 R140/R172, and other nonhotspot IDH mutations. Seventeen (0.4%) cases were identified from 4033 PCa cases in cohort 1 harboring mutually exclusive oncogenic hotspot IDH1 (N = 15, 1 of which was subclonal) or IDH2 (N = 2) mutations, and 20 (0.5%) cases had nonhotspot IDH1/2 mutations. A histologic review of 13 cases with IDH1 hotspot mutations and available material showed grade group 3 or higher disease. Immunohistochemistry was performed on cases with IDH1 hotspot mutations when possible and showed AR, PSA, PSMA, and NKX3.1 positive in all the 4 cases stained. In cohort 2, 9 cases (0.3%) harboring IDH1 hotspot mutations were identified from 2749 patients, and 9 cases carried nonhotspot IDH1/2 mutations. The combined cohorts of 23 PCa cases with clonal IDH1 hotspot mutations had no ETS fusions, SPOP hotspot mutations, and somatic or germline alterations in BRCA1/2, ATM, RB1, or AR; 19 cases with successful microsatellite instability testing were all microsatellite stable. Conversely, among 29 cases with nonhotspot IDH mutations, there were 4 with TMPRSS2::ERG fusions, 6 with SPOP hotspot mutations, and 10 with AR amplifications/hotspot mutations; 8 were microsatellite instability high. Notably, two cases with IDH1 hotspot mutations had psammomatous calcifications. Our findings provide evidence that IDH1 hotspot mutations serve as driver alterations in this rare yet distinct molecular subset of PCa. Further studies are warranted to correlate response to androgen deprivation and IDH inhibitors.

L1 Cell Adhesion Molecule (L1CAM) Expression and Molecular Alterations Distinguish Low-Grade Oncocytic Tumor From Eosinophilic Chromophobe Renal Cell Carcinoma.

Renal low-grade oncocytic tumor (LOT) is a recently recognized renal cell neoplasm designated within the "other oncocytic tumors" category in the 2022 World Health Organization classification system. Although the clinicopathologic, immunohistochemical, and molecular features reported for LOT have been largely consistent, the data are relatively limited. The morphologic overlap between LOT and other low-grade oncocytic neoplasms, particularly eosinophilic chromophobe renal cell carcinoma (E-chRCC), remains a controversial area in renal tumor classification. To address this uncertainty, we characterized and compared large cohorts of LOT (n = 67) and E-chRCC (n = 69) and revealed notable differences between the 2 entities. Clinically, LOT predominantly affected women, whereas E-chRCC showed a male predilection. Histologically, although almost all LOTs were dominated by a small-nested pattern, E-chRCC mainly showed solid and tubular architectures. Molecular analysis revealed that 87% of LOT cases harbored mutations in the tuberous sclerosis complex (TSC)-mTOR complex 1 (mTORC1) pathway, most frequently in MTOR and RHEB genes; a subset of LOT cases had chromosomal 7 and 19q gains. In contrast, E-chRCC lacked mTORC1 mutations, and 60% of cases displayed chromosomal losses characteristic of chRCC. We also explored the cell of origin for LOT and identified L1 cell adhesion molecule (L1CAM), a collecting duct and connecting tubule principal cell marker, as a highly sensitive and specific ancillary test for differentiating LOT from E-chRCC. This distinctive L1CAM immunohistochemical labeling suggests the principal cells as the cell of origin for LOT, unlike the intercalated cell origin of E-chRCC and oncocytoma. The ultrastructural analysis of LOT showed normal-appearing mitochondria and intracytoplasmic lumina with microvilli, different from what has been described for chRCC. Our study further supports LOT as a unique entity with a benign clinical course. Based on the likely cell of origin and its clinicopathologic characteristics, we propose that changing the nomenclature of LOT to "Oncocytic Principal Cell Adenoma of the Kidney" may be a better way to define and describe this entity.

Differential NEUROD1, ASCL1, and POU2F3 Expression Defines Molecular Subsets of Bladder Small Cell/Neuroendocrine Carcinoma With Prognostic Implications.

Small cell carcinomas (SMC) of the lung are now molecularly classified based on the expression of transcriptional regulators (NEUROD1, ASCL1, POU2F3, and YAP1) and DLL3, which has emerged as an investigational therapeutic target. PLCG2 has been shown to identify a distinct subpopulation of lung SMC with stem cell-like and prometastasis features and poor prognosis. We analyzed the expression of these novel neuroendocrine markers and their association with traditional neuroendocrine markers and patient outcomes in a cohort of bladder neuroendocrine carcinoma (NEC) consisting of 103 SMC and 19 large cell NEC (LCNEC) assembled in tissue microarrays. Coexpression patterns were assessed and integrated with detailed clinical annotation including overall (OS) and recurrence-free survival (RFS) and response to neoadjuvant/adjuvant chemotherapy. We identified 5 distinct molecular subtypes in bladder SMC based on the expression of ASCL1, NEUROD1, and POU2F3: ASCL1+/NEUROD1- (n = 33; 34%), ASCL1- /NEUROD1+ (n = 21; 21%), ASCL1+/NEUROD1+ (n = 17; 17%), POU2F3+ (n = 22, 22%), and ASCL1- /NEUROD1- /POU2F3- (n = 5, 5%). POU2F3+ tumors were mutually exclusive with those expressing ASCL1 and NEUROD1 and exhibited lower expression of traditional neuroendocrine markers. PLCG2 expression was noted in 33 tumors (32%) and was highly correlated with POU2F3 expression (P < .001). DLL3 expression was high in both SMC (n = 72, 82%) and LCNEC (n = 11, 85%). YAP1 expression was enriched in nonneuroendocrine components and negatively correlated with all neuroendocrine markers. In patients without metastatic disease who underwent radical cystectomy, PLCG2+ or POU2F3+ tumors had shorter RFS and OS (P < .05), but their expression was not associated with metastasis status or response to neoadjuvant/adjuvant chemotherapy. In conclusion, the NEC of the bladder can be divided into distinct molecular subtypes based on the expression of ASCL1, NEUROD1, and POU2F3. POU2F3-expressing tumors represent an ASCL1/NEUROD1-negative subset of bladder NEC characterized by lower expression of traditional neuroendocrine markers. Marker expression patterns were similar in SMC and LCNEC. Expression of PLCG2 and POU2F3 was associated with shorter RFS and OS. DLL3 was expressed at high levels in both SMC and LCNEC of the bladder, nominating it as a potential therapeutic target.

Early Detection of Prostate Cancer: AUA/SUO Guideline Part II: Considerations for a Prostate Biopsy.

PURPOSE: The summary presented herein covers recommendations on the early detection of prostate cancer and provides a framework to facilitate clinical decision-making in the implementation of prostate cancer screening, biopsy, and follow-up. This is Part II of a two-part series focusing on initial and repeat biopsies, and biopsy technique. Please refer to Part I for discussion of initial prostate cancer screening recommendations. MATERIALS AND METHODS: The systematic review utilized to inform this guideline was conducted by an independent methodological consultant. The systematic review was based on searches in Ovid MEDLINE and Embase and Cochrane Database of Systematic Reviews (January 1, 2000-November 21, 2022). Searches were supplemented by reviewing reference lists of relevant articles. RESULTS: The Early Detection of Prostate Cancer Panel developed evidence- and consensus-based guideline statements to provide guidance in prostate cancer screening, initial and repeat biopsies, and biopsy technique. CONCLUSIONS: The evaluation of prostate cancer risk should be focused on the detection of clinically significant prostate cancer (Grade Group 2 or higher [GG2+]). The use of laboratory biomarkers, prostate MRI, and biopsy techniques described herein may improve detection and safety when a prostate biopsy is deemed necessary following prostate cancer screening.

Early Detection of Prostate Cancer: AUA/SUO Guideline Part I: Prostate Cancer Screening.

PURPOSE: The summary presented herein covers recommendations on the early detection of prostate cancer and provides a framework to facilitate clinical decision-making in the implementation of prostate cancer screening, biopsy, and follow-up. This is Part I of a two-part series that focuses on prostate cancer screening. Please refer to Part II for discussion of initial and repeat biopsies as well as biopsy technique. MATERIALS AND METHODS: The systematic review utilized to inform this guideline was conducted by an independent methodological consultant. The systematic review was based on searches in Ovid MEDLINE and Embase and Cochrane Database of Systematic Reviews (January 1, 2000-November 21, 2022). Searches were supplemented by reviewing reference lists of relevant articles. RESULTS: The Early Detection of Prostate Cancer Panel developed evidence- and consensus-based guideline statements to provide guidance in prostate cancer screening, initial and repeat biopsy, and biopsy technique. CONCLUSIONS: Prostate-specific antigen (PSA)-based prostate cancer screening in combination with shared decision-making (SDM) is recommended. Current data regarding risk from population-based cohorts provide a basis for longer screening intervals and tailored screening, and the use of available online risk calculators is encouraged.

Measuring cancer burden in prostatic needle core biopsies: simplified assessments outperform complex measurements in assessing outcome: evidence to assist pathologist efficiency and minimize datasets.

AIMS: The optimal method of measuring cancer extent in prostate cancer (PCa) biopsies is unknown. METHODS AND RESULTS: Nine hundred eighty-one men with clinically localised PCa managed conservatively were reviewed with follow up. The number of positive cores (NPC), the Maximum Cancer Length in a core (MCL), Total Cancer Length (TCL), and percentage of positive cores (%+cores) was calculated and univariate and multivariate analysis performed using prostate-specific antigen (PSA), T-stage, and Gleason score. The presence of stromal gaps (SG) was recorded. Univariate models were run where SG made a difference to the MCL. All variables showed significant association with PCa death in univariate models. In multivariate models, incorporating PSA, T-stage, and Gleason score, only %+cores was a significant predictor of outcome, with a 10% increase in %+cores resulting in a hazard ratio (HR) of 1.07 (likelihood-ratio test P > Χ2  = 0.01). There were 120 patients where SG made a difference to the MCL and a total of 20 events in this group. Including SG, on univariate analysis the median MCL was 10 mm and HR was 1.16 (P = 0.007), not including SG, the median MCL was 6 mm and HR was 1.23 (P = 6.3 × 10-4 ). Inclusion or exclusion of SG made no significant difference to TCL as a predictor of outcome. CONCLUSION: Cancer extent is a strong predictor of PCa death but only %+cores added to the multivariate model. Expressed as a fraction of NPC/total number of cores, this is the simplest method of assessment, which we favour over more complicated methods in nontargeted biopsies.

Ganglioneuroblastoma intermixed: Clinicopathological implications of diagnosis at presentation and genomic correlations.

BACKGROUND: Ganglioneuroblastoma intermixed (GNBI) is classified as "favorable" histology by International Neuroblastoma Pathology Classification system. However, the International Neuroblastoma Risk Group (INRG) stratifies patients using wider clinicopathological and cytogenetic/molecular parameters. While the diagnosis of GNBI is typically made on resected tumor, it may sometimes be rendered on initial biopsy. We studied GNBI noted at diagnosis to evaluate its correlation with INRG staging and other clinicopathological and molecular features. METHODS: In this retrospective study, clinical, radiological, pathological, cytogenetic, and molecular information from patients with GNBI at diagnosis seen between 1995 and 2021 was analyzed. INRG staging was performed. RESULTS: Of the 15,827 neuroblastoma specimens, GNBI was noted in 237 patients. Of these, 53 had the initial pathological diagnosis of GNBI; median follow-up 3.5 (range: 0.2-14) years. Disease was locoregional in 41 (77%, 16 stage L1 and 25 L2); none relapsed. Twelve (23%) had metastatic disease at presentation; six (50%) relapsed, and two died of disease. MYCN was amplified in two metastatic tumors. Six of 31 (19%) tumors tested had recurrent cytogenetic abnormalities and nonrecurrent somatic gene mutations in 10/23 (43%). The presence of any adverse molecular/cytogenetic findings was associated with metastatic disease (p < .05). For patients with localized GNBI undergoing both biopsy and resection, GNBI was diagnosed in both in 17/19 (90%). CONCLUSIONS: Localized GNBI at diagnosis has excellent long-term clinical outcome even without cytotoxic therapy. For localized GNBI, a biopsy sample is adequate to make the diagnosis. When associated with metastasis at diagnosis, prognosis is poorer, possibly due to associated adverse biological features.

Local Extent of Prostate Cancer at MRI versus Prostatectomy Histopathology: Associations with Long-term Oncologic Outcomes.

Background It is unknown how the imperfect accuracy of MRI for local staging of prostate cancer relates to oncologic outcomes. Purpose To analyze how staging discordances between MRI and histopathologic evaluation relate to recurrence and survival after radical prostatectomy. Materials and Methods Health Insurance Portability and Accountability Act-compliant retrospective analysis of preprostatectomy T2-weighted prostate MRI (January 2001 to December 2006). Extraprostatic extension and seminal vesicle invasion were assessed by using five-point Likert scales; scores of 4 or higher were classified as positive. Biochemical recurrence (BCR), metastases, and prostate cancer-specific mortality rates were estimated with Kaplan-Meier and Cox models. Results A total of 2160 patients (median age, 60 years; interquartile range, 55-64 years) were evaluated. Among patients with histopathologic extraprostatic (pT3) disease (683 of 2160; 32%), those with organ-confined disease at MRI (384 of 683; 56%) experienced better outcomes than those with concordant extraprostatic disease at MRI and pathologic analysis: 15-year risk for BCR, 30% (95% CI: 22, 40) versus 68% (95% CI: 60, 75); risk for metastases, 14% (95% CI: 8.4, 24) versus 32% (95% CI: 26, 39); risk for prostate cancer-specific mortality, 3% (95% CI: 1, 6) versus 15% (95% CI: 9.5, 23) (P < .001 for all comparisons). Among patients with histopathologic organ-confined disease (pT2) (1477 of 2160; 68%), those with extraprostatic disease at MRI (102 of 1477; 7%) were at higher risk for BCR (27% [95% CI: 19, 37] vs 10% [95% CI: 8, 14]; P < .001), metastases (19% [95% CI: 6, 48] vs 3% [95% CI: 1, 6]; P < .001), and prostate cancer-specific mortality (2% [95% CI: 1, 9] vs 1% [95% CI: 0, 5]; P = .009) than those with concordant organ-confined disease at MRI and pathologic analysis. At multivariable analyses, tumor extent at MRI (hazard ratio range, 4.1-5.2) and histopathologic evaluation (hazard ratio range, 3.6-6.7) was associated with the risk for BCR, metastases, and prostate cancer-specific mortality (P < .001 for all analyses). Conclusion The local extent of prostate cancer at MRI is associated with oncologic outcomes after prostatectomy, independent of pathologic tumor stage. This might inform a strategy on how to integrate MRI into a clinical staging algorithm. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gottlieb in this issue.

Papillary renal cell carcinoma: a single institutional study of 199 cases addressing classification, clinicopathologic and molecular features, and treatment outcome.

The morphologic spectrum of type 1 papillary renal cell carcinoma (PRCC) is not well-defined, since a significant proportion of cases have mixed type 1 and 2 histology. We analyzed 199 cases of PRCC with any (even if focal) type 1 features, with a median follow-up of 12 years, to identify clinicopathological features associated with outcome. Ninety-five tumors (48%) of the cohort contained some type 2 component (median amount: 25%; IQR: 10%, 70%). As a group they showed high rates of progression-free (PFS) and cancer-specific survival (CSS). Tumor size, mitotic rate, lymphovascular invasion, sarcomatoid differentiation, sheet-like architecture, and lack of tumor circumscription were significantly associated with CSS (p ≤ 0.015) on univariate analysis. While predominant WHO/ISUP nucleolar grade was associated with PFS (p = 0.013) and CSS (p = 0.030), the presence of non-predominant (<50%) nucleolar grade did not show association with outcome (p = 0.7). PFS and CSS showed no significant association with the presence or the amount of type 2 morphology. We compared the molecular alterations in paired type 1 and type 2 areas in a subset of 22 cases with mixed type 1 and 2 features and identified 12 recurrently mutated genes including TERT, ARID1A, KDM6A, KMT2D, NFE2L2, MET, APC, and TP53. Among 78 detected somatic mutations, 61 (78%) were shared between the paired type 1 and type 2 areas. Copy number alterations, including chromosome 7 and 17 gains, were similar between type 1 and 2 areas. These findings support that type 2 features in a PRCC with mixed histology represent either morphologic variance or clonal evolution. Our study underscores the notion that PRCC with any classic type 1 regions is best considered as type 1 PRCC and assigned the appropriate WHO/ISUP nucleolar grade. It provides additional evidence that type 2 PRCC as a separate category should be re-assessed and likely needs to be abandoned.

Prevalence of High-Risk Prostate Cancer Metastasis to Cloquet's Ilioinguinal Lymph Node.

PURPOSE: Cloquet's node, located at the junction between the deep inguinal nodes and the external iliac chain, is easily accessible and commonly excised during pelvic lymph node dissection for prostate cancer. However, we hypothesize that Cloquet's node is not part of lymphatic metastatic spread of prostate cancer. MATERIALS AND METHODS: Between September 2016 and June 2019, 105 consecutive patients with high-risk prostate cancer (cT3a or Grade Group 4/5, or prostate specific antigen >20 ng/ml) underwent a laparoscopic radical prostatectomy and pelvic lymph node dissection. First, Cloquet's node was identified, retrieved and submitted separately to pathology as right and left Cloquet's node. Next, a pelvic lymph node dissection was completed including the external iliac, obturator fossa and hypogastric nodal packets. Each lymph node was cut into 3 mm slices which were separately embedded in paraffin, stained with hematoxylin and eosin, and examined microscopically. RESULTS: The final analysis included 95 patients. In this high-risk population, the median number of nodes removed was 22 (IQR 18-29); 39/95 patients (41%) had lymph node metastasis. The median number of Cloquet's nodes removed was 2 (IQR 2-3). Cloquet's node was negative in all but 1 patient (1.1%), who had very high-risk features and high metastatic burden in the lymph nodes. CONCLUSIONS: In high-risk prostate cancer, metastasis to the ilioinguinal node of Cloquet is rare. Given this low prevalence, Cloquet's node can be safely excluded from the pelvic lymph node dissection template.

Oncologic Outcomes of Total Length Gleason Pattern 4 on Biopsy in Men with Grade Group 2 Prostate Cancer.

PURPOSE: Gleason Score 7 prostate cancer comprises a wide spectrum of disease risk, and precise substratification is paramount. Our group previously demonstrated that the total length of Gleason pattern (GP) 4 is a better predictor than %GP4 for adverse pathological outcomes at radical prostatectomy. We aimed to determine the association of GP4 length on prostate biopsy with post-prostatectomy oncologic outcomes. MATERIALS AND METHODS: We compared 4 GP4 quantification methods-including maximum %GP4 in any single core, overall %GP4, total length GP4 (mm) across all cores and length GP4 (mm) in the highest volume core-for prediction of biochemical recurrence-free survival after radical prostatectomy using multivariable Cox proportional hazards regression. RESULTS: A total of 457 men with grade group 2 prostate cancer on biopsy subsequently underwent radical prostatectomy. The 3-year biochemical recurrence-free survival probability was 85% (95% CI 81-88). On multivariable analysis, all 4 GP4 quantification methods were associated with biochemical recurrence-maximum %GP4 (HR=1.30; 95% CI 1.07-1.59; p=0.009), overall %GP4 (HR=1.61; 95% CI 1.21-2.15; p=0.001), total length GP4 (HR=2.48; 95% CI 1.36-4.52; p=0.003) and length GP4 in highest core (HR=1.32; 95% CI 1.11-1.57; p=0.001). However, we were unable to identify differences between methods of quantification with a relatively low event rate. CONCLUSIONS: These findings support further studies on GP4 quantification in addition to the ratio of GP3 and GP4 to classify prostate cancer risk. Research should also be conducted on whether GP4 quantification could provide a surrogate endpoint for disease progression for trials in active surveillance.

Neuroendocrine differentiation in the setting of prostatic carcinoma: contemporary assessment of a consecutive series.

AIM: Clinicopathologic characterisation of a contemporary series of neuroendocrine (NE) differentiation in the setting of prostatic carcinoma (PCa) was examined. METHODS AND RESULTS: We reviewed institutional databases for in-house cases with a history of PCa and histopathologic evidence of NE differentiation during the disease course. In all, 79 cases were identified: 32 primary and 47 metastases. Metastatic lesions were in liver (n = 15), lymph node (n = 9), bone (n = 6), lung (n = 3), brain (n = 1), and other sites (n = 13). In all, 63 of 76 (82%) cases with NE differentiation and available history were posttherapy: six postradiation therapy (RT), 24 post- androgen-deprivation therapy (ADT), and 33 post-RT + ADT. Morphologic assessment (n = 79): (i) 23 pure small-cell/high-grade NE carcinoma (HGNEC): 20/23 metastatic; (ii) 10 combined high-grade PCa and small-cell/HGNEC: 9/10 primary; (iii) 15 PCa with diffuse NE immunohistochemistry (IHC) marker positivity/differentiation, associated with nested to sheet-like growth of cells with abundant cytoplasm and prominent nucleoli, yet diffuse positivity for at least one prostatic and one NE IHC marker: all metastatic; (iv) 11 PCa with patchy NE differentiation, displaying more than single-cell positivity for NE IHC: five primary / six metastatic; (v) nine PCa with focal NE marker positive cells: four primary / five metastatic; (vi) 11 PCa with 'Paneth cell-like' change: all primary. CONCLUSIONS: In this contemporary series, the majority of NE differentiation in the setting of PCa was seen posttherapy. We highlight the tendencies of small-cell/HGNEC and PCa with diffuse NE differentiation by IHC to occur in metastatic settings, while morphologically combined high-grade PCa + small-cell/HGNEC and 'Paneth cell-like' change occur in primary disease.

Clinical utility of subclassifying positive surgical margins at radical prostatectomy.

OBJECTIVE: To determine whether subclassification of positive surgical margins (PSMs) increases predictive ability for biochemical recurrence (BCR) and aids clinical decision-making in patients undergoing radical prostatectomy. PATIENTS AND METHODS: We studied 2147 patients with pT2 and pT3a prostate cancer with detailed surgical margin parameters and BCR status. We compared a base model, a linear predictor calculated from the Memorial Sloan Kettering Cancer Center postoperative nomogram (prostate-specific antigen, pathological tumour grade and stage), with the addition of surgical margin status to five additional models (base model plus surgical margin subclassifications) to evaluate enhancement in predictive accuracy. Decision curve analysis (DCA) was performed to determine the clinical utility of parameters that enhanced predictive accuracy. RESULTS: Among 2147 men, 205 had PSMs, and 231 developed BCR. Discrimination for the base model with addition of surgical margin status was high (c-index = 0.801) and not meaningfully improved by adding surgical margin subclassification in the full cohort. In analyses considering only men with PSMs (N = 55 with BCR), adding surgical margin subclassification to the base model increased discrimination for total length of all PSMs - alone or with maximum Gleason grade at the margin (c-index improvement = 0.717 to 0.752 and 0.753, respectively). DCA demonstrated a modest benefit to clinical utility with the addition of these parameters. CONCLUSIONS: Specific subclassification parameters add predictive accuracy for BCR and may aid clinical utility in decision-making for patients with PSMs. These findings may be useful for patient counselling and future adjuvant therapy trial design.

Adverse histology, homozygous loss of CDKN2A/B, and complex genomic alterations in locally advanced/metastatic renal mucinous tubular and spindle cell carcinoma.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma with characteristic histologic features and chromosomal alterations. Although typically indolent, a small subset of cases has been reported to exhibit aggressive clinical behavior. We retrospectively identified 33 patients with MTSCC, consisting of 10 cases of locally advanced/metastatic MTSCC (pT3 or N1 or M1) and 23 kidney-confined MTSCC (pT1/T2) without disease recurrence or progression. Utilizing a single-nucleotide polymorphism array and a targeted next-generation sequencing platform, we examined genome-wide molecular alterations in 24 cases, including 11 available samples from 8 patients with locally advanced/metastatic MTSCC. Ten patients with locally advanced/metastatic MTSCC were 8 females (80%) and 2 males (20%). At nephrectomy, 7 of these 10 cases (70%) were pT3 or pN1 while the remaining 3 (30%) were pT1/T2. Eight patients (80%) developed metastases and common sites included lymph node (4, 40%), bone (4, 40%), and retroperitoneum (3, 30%). Four patients died of disease (40%) during follow-up. Locally advanced/metastatic MTSCCs shared typical MTSCC genomic profiles with loss of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22, while some exhibited additional complex genomic alterations, most frequently a relative gain of 1q (7/8). Homozygous loss of CDKN2A/B was observed in 3 (38%) locally advanced/metastatic MTSCCs. Tumor necrosis, solid nested/sheet pattern, irregular trabecular/single-file infiltration in a desmoplastic stroma, lymphovascular space invasion, and increased mitotic activity were associated with locally advanced/metastatic MTSCCs (all p < 0.05). Our findings reveal that MTSCCs with aggressive clinical behavior have progressed through clonal evolution; CDKN2A/B deletion and additional complex genomic abnormalities may contribute to this process. Recognizing the morphologic presentation of high-grade MTSCC and evaluating adverse histologic features seen in these tumors can help establish a definitive diagnosis and stratify patients for treatment and prognostication.

Oncologic Outcomes after Localized Prostate Cancer Treatment: Associations with Pretreatment Prostate Magnetic Resonance Imaging Findings.

PURPOSE: We investigated whether T2-weighted magnetic resonance imaging findings could improve upon established prognostic indicators of metastatic disease and prostate cancer specific survival. MATERIALS AND METHODS: For a cohort of 3,406 consecutive men who underwent prostate magnetic resonance imaging before prostatectomy (2,160) or radiotherapy (1,246) between 2001 and 2006, T2-weighted magnetic resonance imaging exams were retrospectively interpreted and categorized as I) no focal suspicious lesion, II) organ confined focal lesion, III) focal lesion with extraprostatic extension or IV) focal lesion with seminal vesicle invasion. Clinical risk was recorded based on European Association of Urology (EAU) guidelines and the Cancer of the Prostate Risk Assessment (CAPRA) scoring system. Survival probabilities and c-indices were estimated using Cox models and inverse probability censoring weights, respectively. RESULTS: The median followup was 10.8 years (IQR 8.6-13.0). Higher magnetic resonance imaging categories were associated with a higher likelihood of developing metastases (HR 3.5-18.1, p <0.001 for all magnetic resonance imaging categories) and prostate cancer death (HR 3.1-29.7, p <0.001-0.025); these associations were statistically independent of EAU risk categories, CAPRA scores and treatment type (surgery vs radiation). Combining EAU risk or CAPRA scores with magnetic resonance imaging categories significantly improved prognostication of metastases (c-indices: EAU: 0.798, EAU + magnetic resonance imaging: 0.872; CAPRA: 0.808, CAPRA + magnetic resonance imaging: 0.877) and prostate cancer death (c-indices: EAU 0.813, EAU + magnetic resonance imaging: 0.889; CAPRA: 0.814, CAPRA + magnetic resonance imaging: 0.892; p <0.001 for all). CONCLUSION: Magnetic resonance imaging findings of localized prostate cancer are associated with clinically relevant long-term oncologic outcomes. Combining magnetic resonance imaging and clinicopathological data results in more accurate prognostication, which could facilitate individualized patient management.

Risk of Metastasis in Men with Grade Group 2 Prostate Cancer Managed with Active Surveillance at a Tertiary Cancer Center.

PURPOSE: We studied the risk of metastatic prostate cancer development in men with Grade Group 2 disease managed with active surveillance at Memorial Sloan Kettering Cancer Center. MATERIALS AND METHODS: A total of 219 men with Grade Group 2 prostate cancer had disease managed with active surveillance between 2000 and 2017. Biopsy was performed every 2 to 3 years, or upon changes in magnetic resonance imaging, prostate specific antigen level or digital rectal examination. The primary outcome was development of distant metastasis. The Kaplan-Meier method was used to estimate treatment-free survival. RESULTS: Median age at diagnosis was 67 years (IQR 61-72), median prostate specific antigen was 5 ng/ml (IQR 4-7) and most patients (69%) had nonpalpable disease. During followup 64 men received treatment, including radical prostatectomy in 36 (56%), radiotherapy in 20 (31%), hormone therapy in 3 (5%) and focal therapy in 5 (8%). Of the 36 patients who underwent radical prostatectomy 32 (89%) had Grade Group 2 disease on pathology and 4 (11%) had Grade Group 3 disease. Treatment-free survival was 61% (95% CI 52-70) at 5 years and 49% (95% CI 37-60) at 10 years. Three men experienced biochemical recurrence, no men had distant metastasis and no men died of prostate cancer during the followup. Median followup was 3.1 years (IQR 1.9-4.9). CONCLUSIONS: Active surveillance appears to be a safe initial management strategy in the short term for carefully selected and closely monitored men with Grade Group 2 prostate cancer treated at a tertiary cancer center. Definitive conclusions await further followup.

Long-Term Outcomes of Active Surveillance for Prostate Cancer: The Memorial Sloan Kettering Cancer Center Experience.

PURPOSE: We report oncologic outcomes for men with Grade Group 1 prostate cancer managed with active surveillance at a tertiary cancer center. MATERIALS AND METHODS: A total of 2,907 patients were managed with active surveillance between 2000 and 2017, of whom 2,664 had Grade Group 1 disease. Patients were recommended confirmatory biopsy to verify eligibility and were followed semiannually with prostate specific antigen, digital rectal examination and review of symptoms. Magnetic resonance imaging was increasingly used in recent years. Biopsy was repeated every 2 to 3 years or after a sustained prostate specific antigen increase or changes in magnetic resonance imaging/digital rectal examination. The Kaplan-Meier method was used to estimate probabilities of treatment, progression and development of metastasis. RESULTS: Median patient age at diagnosis was 62 years. For men with Grade Group 1 prostate cancer the treatment-free probability at 5, 10 and 15 years was 76% (95% CI 74-78), 64% (95% CI 61-68) and 58% (95% CI 51-64), respectively. At 5, 10 and 15 years there were 1,146, 220 and 25 men at risk for metastasis, respectively. Median followup for those without metastasis was 4.3 years (95% CI 2.3-6.9). Distant metastasis developed in 5 men. Upon case note review only 2 of these men were deemed to have disease that could have been cured on immediate treatment. The risk of distant metastasis was 0.6% (95% CI 0.2-2.0) at 10 years. CONCLUSIONS: Active surveillance is a safe strategy over longer followup for appropriately selected patients with Grade Group 1 disease following a well-defined monitoring plan.

Genomic landscape of inverted urothelial papilloma and urothelial papilloma of the bladder.

Inverted urothelial papilloma (IUP) and urothelial papilloma (UP) are rare urothelial neoplasms that typically follow a benign clinical course. Oncogenic mutations in FGFR3, HRAS, and the TERT promoter have been reported in these entities but no comprehensive molecular analysis has been performed. We sought to characterize the genomic landscape of IUP and UP using whole-exome and targeted next-generation sequencing. In IUP, 10 of 11 tumors harbored oncogenic hotspot mutations in HRAS and the remaining tumor had an oncogenic KRAS mutation. None of the IUP tumors harbored TERT promoter or FGFR3 mutations. In UP, 8 of 11 tumors had oncogenic KRAS mutations and two had oncogenic HRAS mutations. One UP tumor had oncogenic mutations in FGFR3, PIK3CA, and the TERT promoter, and arose in a patient with recurrent non-invasive papillary urothelial carcinomas. In contrast to urothelial carcinoma, the APOBEC mutational signature was not present in any IUP and UP tumors, and oncogenic alterations in chromatin remodeling genes were uncommon in both IUP and UP. The current study suggests that IUP and UP are driven primarily by RAS pathway activation and lack the more common genomic features of urothelial cancers. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Extensive disease among potential candidates for hemi-ablative focal therapy for prostate cancer.

OBJECTIVE: To examine a set of proposed eligibility factors for hemi-ablative focal therapy in prostate cancer and to determine the likelihood of residual extensive disease. METHODS: We retrospectively analyzed data from 98 patients with unilateral prostate cancer on biopsy with detailed tumor maps from whole-mount slides and preoperative magnetic resonance imaging data. These patients met the focal therapy consensus meeting inclusion criteria (prostate-specific antigen <15 ng/mL, clinical stage T1c-T2a and Gleason score 3 + 3 or 3 + 4 on needle biopsy), and underwent radical prostatectomy between 2000 and 2014. Extensive disease was defined as having Gleason pattern 4/5 in bilateral lobes, any extraprostatic extension, seminal vesicle invasion or lymph node invasion. Both lobes of the prostate were scored on magnetic resonance imaging. Preoperative characteristics including biopsy and magnetic resonance imaging data were used to predict extensive disease. RESULTS: Among our cohort of 98 patients, 40% (95% CI 30-50%) had extensive disease. A total of 33% (95% CI 24-43%) had Gleason pattern 4/5 in both lobes with a median Gleason pattern 4/5 tumor volume in the biopsy negative lobe of 0.06 cm3 , 17 patients had pathological tumor stage ≥3 and one patient had lymph node invasion. CONCLUSIONS: An important number of patients meeting the focal therapy consensus meeting inclusion criteria can present extensive disease. Further studies using targeted biopsies might provide more accurate information about the selection of focal therapy candidates.

Tubulocystic renal cell carcinoma: a distinct clinicopathologic entity with a characteristic genomic profile.

Tubulocystic renal cell carcinoma, a unique tumor, was recently included as a new entity in the World Health Organization classification of renal tumors. It has variably been reported to be related to other renal cell carcinomas, including papillary renal cell carcinoma, fumarate hydratase-deficient carcinoma, and others, likely because many such carcinomas may show variable amounts of tubulocystic architecture. The published data characterizing the molecular features of these tumors are inconsistent. We studied nine "pure" tubulocystic renal cell carcinomas, as defined by International Society of Urologic Pathologists (ISUP) and World Health Organization (WHO), by targeted next-generation sequencing, and fluorescence in situ hybridization for X and Y chromosomes, to investigate if these show any unique characteristics or any overlap with known mutational/molecular profiles or copy number alterations in other subtypes of renal cell carcinoma. All nine tubulocystic carcinomas demonstrated combined losses at chromosome 9 and gains at chromosome 17, as well as, loss of chromosome Y (in 5/5). None of the tumors showed mutational profiles characteristic of other renal neoplasms, including those seen in fumarate hydratase-deficient renal cell carcinoma. Recurrent mutations in chromatin-modifying genes, KMT2C and KDM5C, were detected in two of nine tumors. Thus, tubulocystic renal cell carcinoma, if defined strictly, at the clinical and pathologic level, demonstrates genomic features distinct from other subtypes of renal cell carcinoma. These findings support the contention that tubulocystic renal cell carcinoma should be diagnosed only using strict morphological criteria and only when presenting in a "pure" form; presence of variable papillary, poorly differentiated, or other architectural patterns most likely do not belong to the category of tubulocystic renal cell carcinoma.