Micropapillary Urothelial Carcinoma Research Articles

Abstract IA04: Molecular alterations in variant morphology

Abstract Bladder cancer can be divided into several major subtypes that include urothelial carcinoma, squamous cell carcinoma, adenocarcinoma and neuroendocrine carcinoma. Urothelial carcinoma, the most common form of bladder cancer, is further subdivided into numerous histologic variants based on distinct morphologic features. While histologic characterization remains the most important factor in diagnosis and patient management, emerging molecular data across bladder cancer subtypes and variants may potentially alter how bladder cancer is classified. Large scale -omic analytics have uncovered unique signatures within major bladder cancer subtypes. In addition, molecular groupings and unique single-gene alterations have been identified within urothelial carcinoma and its many morphologic variants, including plasmacytoid urothelial carcinoma and micropapillary urothelial carcinoma. We will review molecular alterations in major categories of bladder cancer and urothelial carcinoma variants. Many of these molecular alterations could potentially be used in revised classification, diagnosis, and therapy of bladder cancer. Citation Format: Donna E. Hansel. Molecular alterations in variant morphology [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2019 May 18-21; Denver, CO. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(15_Suppl):Abstract nr IA04.

Prognostic values of the clinicopathological characteristics and survival outcomes in micropapillary urothelial carcinoma of the bladder: A SEER database analysis

PurposeTo study prognostic values of the clinicopathological characteristics and survival outcomes in micropapillary urothelial carcinoma (MPUC) of the urinary bladder.MethodWe used the national Surveillance, Epidemiology, and End Results database (2004‐2016) to compare MPUC with transitional cell carcinoma (TCC) and to investigate prognostic values of clinicopathological characteristics, as well as survival outcomes, in MPUC of the urinary bladder. A multivariable Cox proportional hazard model, subgroup analyses, and propensity score matching were used.ResultsIn all, 519 patients with MPUC and 154 453 patients with TCC were enrolled. Compared with TCC, patients with MPUC had a higher rate of muscle invasive disease (P < .001), lymph node metastasis (P < .001), and distal metastasis (P < .001), as well as higher tumor grade (P < .001). According to the survival analyses, the MPUC group also had lower survival probability in both cancer‐specific mortality (CSM) (P < .0001) and overall mortality (OM) analyses (P < .0001). Cox proportional hazard regression showed that the MPUC group had a higher risk of OM (hazard ratios [HR] = 1.39, 95% confidence intervals [CI] = 1.22‐1.57, P < .0001), although the CSM (HR = 1.18, 95% CI = 1.00‐1.40, P = .0505) in that group was fair. In the subgroup analysis, only MPUC patients without distal metastasis faced a higher risk of CSM (HR = 1.33, 95% CI = 1.101.61, P < .0001).ConclusionsMicropapillary urothelial carcinoma prognosis is poorer than that of TCC. Micropapillary urothelial carcinoma is an independent prognostic factor for OM in patients with urinary bladder cancer.

Micropapillary urothelial carcinoma (mpUC): A comparative analysis of oncologic outcomes compared to conventional urothelial carcinoma (CUC).

459 Background: MpUC is a rare variant associated with adverse outcomes. We describe our institutional experience and compare clinicopathologic features and survival between patients with mpUC and CUC. Methods: Patients with mpUC or CUC at radical cystectomy (RC) or transurethral resection of bladder tumor were identified from a retrospective institutional RC database. Clinicopathologic/treatment data were extracted and compared using T-test and χ2 test. Recurrence free survival (RFS) and overall survival (OS) from RC to first recurrence or death were estimated using the KM method. Factors identified as significant in univariable (UVA) Cox regression analysis for OS were included in multivariable analysis (MVA). Results: 64 consecutive patients with mpUC and 457 with CUC were identified (2003 - 2018); 36 (56%) and 188 (41%) received neoadjuvant chemotherapy (NAC). MpUC had higher incidence of pT3/4 (41% vs. 28%) or pN+ disease (39% vs. 17%), carcinoma in-situ (52% vs. 24%) and lymphovascular invasion (LVI, 39% vs. 16%) at RC, compared to CUC (all p &lt; 0.05). Rates of ypT0N0 after NAC were comparable between groups (25% vs. 35%, p = 0.26). Median follow-up was 62 months (95% CI 55.4 – 68.3). 5-year RFS was 24% (mpUC) vs. 58% (CUC), p = 0.001. 5-year OS was 40% (mpUC) vs. 69% (CUC), p = 0.001. MpUC histology was not independently associated with OS after adjusting for pT stage, node ratio (# nodes +/ # nodes removed) and ECOG status (Table). Conclusions: Patients with mpUC presented with advanced stage at RC, while they showed inferior RFS and OS, when compared to CUC. However, rates of pathologic response to NAC were comparable to CUC and mpUC was not associated with OS in MVA. Further studies are needed to define the optimal management of this variant. [Table: see text]

Variant morphology and random chromosomal integration of BK polyomavirus in posttransplant urothelial carcinomas.

BK polyomavirus (BKPyV) causes major complications in solid organ transplant recipients but little is known about its role in the development of urothelial carcinoma (UC) during immunosuppression. Immunohistochemistry (IHC) screening for polyomavirus large T antigen (LTag) was performed in 94 micropapillary UC (MPUC), 480 unselected UC, 199 muscle invasive UC (including 83 UC with variant differentiation), 76 cases of plasmocytoid, nested and large nested UC and 15 posttransplant UC. LTag expressing UC were reevaluated regarding their histomorphological features and characterized by IHC for p53 and HER2, chromogenic in situ hybridization for HER2 and SNaPshot analysis of the TERT promoter and HRAS. Real-time PCR and next generation sequencing (NGS) were performed to search for BKPyV-DNA and for variants in the tumor and viral genomes. We detected five LTag expressing UC which were diagnosed between 2 and 18 years after kidney (n = 4) or heart (n = 1) transplantation. 89 MPUC without history of organ transplantation and overall 755 UC (including cases with variant histology) were LTag negative. Of the five LTag expressing UC, three were MPUC, one showed extensive divergent differentiation with Mullerian type clear cell carcinoma, and one displayed focal villoglandular differentiation. All five tumors had aberrant nuclear p53 expression, 2/5 were HER2-amplified, and 3/5 had TERT promoter mutations. Within the 50 most common cancer related genes altered in UC we detected very few alterations and no TP53 mutations. BKPyV-DNA was present in 5/5 UC, chromosomal integration of the BKPyV genome was detectable in 4/5 UC. Two UC with BKPyV integration showed small deletions in the BKPyV noncoding control region (NCCR). The only UC without detectable BKPyV integration had a high viral load of human herpesvirus 6 (HHV-6). Our results suggest that LTag expression of integrated BKPyV genomes and resulting p53 inactivation lead to aggressive high-grade UC with unusual, often micropapillary morphology.

Micropapillary urothelial carcinoma of urinary bladder displays immunophenotypic features of luminal and p53-like subtypes and is not a variant of adenocarcinoma

ObjectivesMicropapillary urothelial carcinoma of the urinary bladder (MPUC) is a rare variant of urothelial carcinoma which has aggressive clinical characteristics. The objective is to investigate the molecular subtypes of MPUC and the impact to the clinical outcome and determine whether MPUC represents a variant of adenocarcinoma. Materials and MethodsWe evaluated surrogate immunohistochemical markers of luminal, basal, and p53-like subtypes and correlated with prognosis and the expression of markers related to bladder adenocarcinoma and glandular differentiation in 56 cases of MPUC (10 cases of transurethral resection and 46 cases of radical cystectomy). Biomarker expression in co-existing conventional urothelial carcinoma was also analyzed. Cox regression analysis was performed to study the impact of molecular subtype on the clinical outcome. ResultsThirty-four cases (61%) met criteria for the luminal subtype. Twenty-two cases (39%) displayed a p53-like subtype. In contrast, 40/56 (71%) cases of coexisting conventional urothelial carcinoma were classified as luminal subtype and 16/56 (29%) cases were designated as p53-like subtype. There was no significant survival difference between luminal subtype and p53-like subtype. CDX2, villin, and cadherin 17 were negative in all cases. MUC1 was strongly and diffusely expressed in the stroma-facing surface of MPUC tumor cells in all the cases. ConclusionsOur findings suggest that MPUC possesses characteristics of luminal and p53-like subtypes, and does not harbor phenotypic features of the basal subtype. There is no significant difference in the prognosis between luminal and p53-like subtype MPUC. MPUC is not a variant of adenocarcinoma and does not represent a form of glandular differentiation, in contrast to other organ sites.

Analysis of HER2 mutant bladder urothelial carcinomas reveals unique mutational signature.

460 Background: Early work has described the presence of HER2 alterations in metastatic urothelial carcinomas (UC), particularly the micropapillary urothelial carcinoma (MPUC) subtype. We reviewed the genomic profiles of a large set of UC cases to further characterize HER2 altered UCs and how such alterations would suggest benefit from the expanding array of anit-HER2 therapeutics. Methods: Tissue from 2,150 UCs were assayed using hybrid capture-based comprehensive genomic profiling (CGP) of 186 to 315 genes plus introns from 14 to 28 genes commonly arranged in cancer. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA. Results: Within the UC dataset 74.6% of cases were male (1603/2150), with a median TMB of 7 mut/Mb. 383 genomic alterations (GA) of HER2 were identified in 15.5% (334/2150) of cases which exhibited a median TMB of 8.7 mut/Mb (p &lt; 1E-5) vs patients with wildtype HER2, median TMB of 7 mut/Mb. The most frequent HER2 alterations were amplification HER2amp (45.7%, 175/383), S310F (19.8%, 76/383), and S310Y (7/6%, 29/383). Patients harbouring a HER2amp, S310 (n = 105) exhibited a median TMB of 8.7 and 12.2 mut/Mb, respectively. 42 patients presented with multiple ( &gt; 1) HER2 GA and exhibited a median TMB of 11.3 mut/Mb (p &lt; 0.1) vs patients with single HER2 GA, median TMB of 12.3 mut/Mb. Of patients with multiple HER2 alterations, 57% (24/42) harbored a HER2amp. The most common co-occuring HER2 alteration pair was an amplification and extracellular S310X alteration (38.1%, 16/42). Of these 16, the median TMB was 19.5 mut/Mb (average 22.7 mut/Mb). Morphological assessments were performed on the 24 cases harbouring a HER2amp and an additional HER2 GA. 8 cases displayed MPUC features 44.4% (8/18; 6 cases histology unavailable); of these MPUC cases, 75% (6/8), harboured a HER2 amp and S310 extracellular mutation. Conclusions: CGP of bladder urothelial (transitional cell) carcinomas reveals subclasses of HER2 altered cases. Drawing on recent advances in targeting HER2 alterations in breast cancer, dual HER2 blockade (e.g. combinations of mAB/TKI/mAB+ADC) may be needed for HER2amp cases. For cases with both HER2amp and S310 GA, neratinib monotherapy may be the agent of choice and thus may be effective in MPUC.

Infiltrating high grade micropapillary urothelial carcinoma of the bladder in association with bk virus in kidney-pancreas transplant recipient: a case report

Infiltrating high grade micropapillary urothelial carcinoma of the bladder in association with bk virus in kidney-pancreas transplant recipient: a case report

Implications of micropapillary urothelial carcinoma variant on prognosis following radical cystectomy: A multi-institutional investigation

PurposeTo determine the association of micropapillary urothelial carcinoma (MUC) variant histology with bladder cancer outcomes after radical cystectomy. Materials and MethodsInformation on MUC patients treated with radical cystectomy was obtained from five academic centers. Data on 1,497 patients were assembled in a relational database. Tumor histology was categorized as urothelial carcinoma without any histological variants (UC; n = 1,346) or MUC (n = 151). Univariable and multivariable models were used to analyze associations with recurrence-free (RFS) and overall (OS) survival. ResultsMedian follow-up was 10.0 and 7.8 years for the UC and MUC groups, respectively. No significant differences were noted between UC and MUC groups with regard to age, gender, clinical disease stage, and administration of neoadjuvant and adjuvant chemotherapy (all, P ≥ 0.10). When compared with UC, presence of MUC was associated with higher pathologic stage (organ-confined, 60% vs. 27%; extravesical, 18% vs. 23%; node-positive, 22% vs. 50%; P < 0.01) and lymphovascular invasion (29% vs. 58%; P < 0.01) at cystectomy. In comparison with UC, MUC patients had poorer 5-year RFS (70% vs. 44%; P < 0.01) and OS (61% vs. 38%; P < 0.01). However, on multivariable analysis, tumor histology was not independently associated with the risks of recurrence (P = 0.27) or mortality (P = 0.12). ConclusionsThis multi-institutional analysis demonstrated that the presence of MUC was associated with locally advanced disease at radical cystectomy. However, clinical outcomes were comparable to those with pure UC after controlling for standard clinicopathologic predictors.

Urothelial Carcinoma In Situ of the Bladder With Glandular Differentiation: Report of 92 Cases.

Urothelial carcinoma in situ (CIS) of the bladder with glandular differentiation (CIS-GL) is rare with some showing an association with small cell carcinoma. There is a paucity of data on whether CIS-GL diagnosed in the absence of invasive carcinoma is associated with an increased risk of developing small cell carcinoma of the bladder. Twenty-seven cases of CIS-GL were identified from the consult files of one of the authors from 2008 to 2015 without prior or coexisting invasive carcinoma at the time of diagnosis. Sixty-five additional cases were identified with concurrent CIS-GL and invasive carcinoma to assess the nature of the association. Of the 27 cases with only CIS-GL without invasive carcinoma at the time of diagnosis, follow-up time ranged from 11 to 91 months (mean, 41.1 mo). Of 24/27 cases with follow-up information: 13 (54.2%) had no evidence of disease at last follow-up, typically treated with induction and maintenance Bacillus Calmette-Guerin; 3 (12.5%) patients underwent radical cystectomy due to disease progression; 2 (8.3%) patients had recurrent CIS, and 1 (4.2%) had recurrent noninvasive low-grade papillary urothelial carcinoma (UC) (these patients underwent transurethral resection of the bladder and Bacillus Calmette-Guerin treatment); 2 (8.3%) patients died of metastatic UC; and 3 (12.5%) died of other or unknown causes. Of note, none of these 24 patients developed small cell carcinoma. Of the 65 cases with concurrent CIS-GL and invasive carcinoma, the invasive carcinoma was: pure UC in 29/65 (45%); invasive UC with GL in 13/65 (20%); coexisting small cell carcinoma and invasive UC in 8/65 (12%); plasmacytoid UC in 7/65 (11%); sarcomatoid UC in 3/65 (5%); micropapillary UC in 2/65 (3%); squamous in 2/65 (3%); and signet ring with colloid features in 1/65 (1%). Patients with CIS-GL without invasive carcinoma are at significant risk for cancer progression and in a minority of cases at risk for death from bladder carcinoma, similar to usual CIS. Typically, subsequent invasive carcinoma is UC rather than adenocarcinoma. Similarly, the largest fraction of concurrent invasive carcinoma and CIS-GL is UC. However, this study for the first time demonstrates the wide spectrum of other UC variants that coexist with CIS-GL, including a sizeable minority of cases with invasive UC with GL. Although there is a disproportionately high fraction of CIS-GL with coexisting small cell carcinoma, small cell carcinoma does not seem to develop at high frequency following the diagnosis and treatment of CIS-GL.

Micropapillary urothelial carcinoma: evaluation of HER2 status and immunohistochemical characterization of the molecular subtype

Comprehensive molecular analyses of urothelial bladder cancer (UBC) have defined distinct subtypes with potential therapeutic implications. In this study, we focused on micropapillary urothelial carcinoma (MPUC), an aggressive, histomorphologically defined rare variant. Apart from genetic alterations shared with conventional UBC, alterations of the HER2 gene have been reported in higher frequencies. However, only small cohorts of MPUCs have been analyzed, and the real impact is still unclear. We collected a cohort of 94 MPUCs and immunohistochemically tested HER2, basal (CD44, CK5, EGFR, p63) and luminal (CD24, FOXA1, GATA3, CK20) markers to allocate MPUC to a molecular subtype. Additionally, HER2 amplification status was assigned by chromogenic in situ hybridization. Sanger sequencing of exon 4 and 8 was used to test for HER2 mutations. Kruskal-Wallis test was calculated to compare marker distribution between proportions of the MPUC component. HER2 2+/3+ staining scores were identified in 39.6% of 91 analyzed MPUCs and were not differentially distributed among the proportion of the MPUC component (P = .89). Additionally, CISH analysis revealed 30% of HER2-amplified tumors independently of the MPUC fraction. In 6/90 evaluable MPUCs, a p.S310F HER2 mutation was detected. Overexpression of luminal markers was observed in the majority of MPUC. Our investigations of the largest cohort of analyzed MPUC demonstrate that HER2 overexpression and amplifications are common genetic alterations and identification of overexpressed luminal markers allows subclassification to the luminal subtype. These findings highlight the need of histomorphological recognition of MPUC and analysis of HER2 status and the luminal molecular subtype for potential targeted therapeutic strategies.

Intratumoral heterogeneity of ERBB2 amplification and HER2 expression in micropapillary urothelial carcinoma

Micropapillary urothelial carcinoma (MPUC) is a rare but an aggressive variant of urothelial carcinoma. MPUC has been shown to commonly exhibit ERBB2 amplification and HER2 protein overexpression, but the frequency and distribution of these findings within micropapillary (MP) and not otherwise specified (NOS) components of tumors with mixed histology have not been addressed. Therefore, we evaluated ERBB2 amplification and HER2 expression in 43 MPUC cases by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Of the 35 tumors containing both MP and NOS components, ERBB2 amplification was present in both the MP and NOS components of 12 tumors (34.3%), in only the MP component of 11 tumors (31.4%), and exclusively in the NOS component of 4 tumors (11.4%). HER2 protein overexpression was significantly more commonly present in the MP component compared to the NOS component within the same tumor (68.6% versus 34.3%, P = .012). Overall, there was a moderately positive correlation between HER2 protein expression and ERBB2 amplification in both MP (ρ = 0.59, P < .001) and NOS (ρ = 0.70, P < .001) components. All MP/NOS areas with IHC score 3+ and none of MP/NOS areas with IHC score 0 were associated with ERBB2 amplification. We conclude that ERBB2 amplification and HER2 overexpression are preferentially but not exclusively identified in the MP component compared to the NOS component within the same tumor. Our findings identify the presence of intratumoral heterogeneity of ERBB2 amplification and HER2 expression in MPUC and provide grounds for further investigation into the mechanisms underlying the development of MPUC.

Clinicopathologic factors, treatment patterns, and outcomes in micropapillary urothelial carcinoma (UC).

439 Background: Micropapillary UC remains rare yet with an aggressive phenotype. Limited data exists regarding the optimal management of this variant in the contemporary era. Methods: A retrospective analysis was performed to identity patients (pts) with micropapillary UC at the Cleveland Clinic (1997-2017). Demographic, clinico-pathological, treatment regimens, and clinical outcomes, e.g. progression-free and overall survival (PFS and OS) data were collected. Results: A total of 102 pts with median age 70.5 (46-90) at diagnosis, 84%, men, 17% never smokers were identified. Stage at diagnosis for 68 pts with available data was T1 in 29, T2 in 36, T3 in 1, T4 in 2, N+ in 5, and M+ in 4 pts, respectively. Twelve pts were initially treated with intravesical therapy for NMIBC with 58% progressing to higher stage. Overall, 81% of pts had cystectomy; of those 19% had neoadjuvant chemotherapy (NAC; 81% cisplatin-based, median 3 cycles), 21 pts received adjuvant chemotherapy and 3 pts adjuvant radiation. Of 12 pts with available data, 4 had down-staging with NAC with 1 pCR. Pathologic stage was 0is, I, II, III, IV in 4%, 10%, 9%, 9%, and 67% respectively. Overall, 61 pts had recurrent or de-novo metastatic disease (most nodal/local-regional recurrence). For patients with recurrence post-surgery (n = 31), 35% received systemic chemotherapy, 16% had salvage surgery, 10% had salvage radiation, 19% had best supportive care, and the rest were lost to follow-up or refused treatment. The most common 1st-line regimen included platinum-doublet (46%), other combinations (23%), single-agent (23%) and immune checkpoint inhibitors (8%). Overall response (CR/PR) to 1st-line treatment was 38% and median PFS was 8 months (95%CI 0-16.4). Overall, 29 pts died with recurrent/metastatic disease with a median OS (from time of diagnosis) of 39.3 months (95%CI 28.4-50.2) Median OS (from time of diagnosis) for pts treated with cystectomy was 47.1 months (95%CI 23.9-50.2). Conclusions: Micropapillary UC was associated with advanced pathologic stage at cystectomy and limited use of NAC. Responses were noted with NAC and 1st line systemic treatment. Further validation can assist in prognostication and selection/stratification in future trials.

Cell Polarity Reversal Distinguishes True Micropapillary Growth From Retraction Artifact in Invasive Urothelial Carcinoma.

Focal micropapillary features in invasive urothelial carcinoma is sometimes difficult to distinguish from retraction artifact morphologically. Cell polarity reversal has been demonstrated in micropapillary tumors by epithelial membrane antigen (EMA) immunostaining. We have previously described the use of E-cadherin as a cell polarity marker in ovarian micropapillary serous borderline tumors. The aim of this study was to evaluate the utility of immunohistochemistry for EMA and E-cadherin in differentiating micropapillary urothelial carcinoma from retraction artifact. We identified 29 invasive urothelial carcinomas with micropapillary features and 30 invasive urothelial carcinomas without reported micropapillary features but with areas of retraction artifact. Cell polarity reversal was considered present if E-cadherin showed membranous apical cup-like staining or if EMA demonstrated a well-defined basal staining towards the stroma. Twenty-seven of 29 cases (93%) of urothelial carcinoma with micropapillary features demonstrated EMA or E-cadherin staining patterns consistent with cell polarity reversal. Staining consistent with micropapillary architecture was identified with both markers in 20 of these 27 cases (74%). Six cases showed reversal of polarity by E-cadherin alone, whereas 1 case showed polarity reversal by EMA alone. Retraction artifacts showed circumferential staining by E-cadherin and lacked well-defined basal staining by EMA. Three cases originally classified as with retraction artifact showed reversal of cell polarity by both EMA and E-cadherin and were reclassified as micropapillary. Our data show that pathologists can reliably make this distinction in most cases. However, in some cases with ambiguous features, EMA and E-cadherin immunostaining may aid in resolving this diagnostic dilemma.

Clinicopathological implications to micropapillary bladder urothelial carcinoma of the presence of sialyl Lewis X-decorated mucin 1 in stroma-facing membranes

ObjectivesBladder urothelial carcinoma (UC) comprises more than 90% of all bladder cancers. Among several UC variants, micropapillary UC (MPUC) is a rare one with high potential for lymphovascular invasion and subsequent lymph node metastasis. Histologically, MPUC is characterized by the presence of small papillary carcinoma cell clusters surrounded by lacunar spaces. Immunohistochemically, the outer circumference of these clusters, that is, the stroma-facing membrane of carcinoma cells, is reportedly almost invariably positive for mucin 1 (MUC1) protein and to a lesser extent for sialyl Lewis X (sLeX) carbohydrates; however, the clinicopathological implications of these expression patterns have not been fully investigated. Materials and methodsWe performed immunohistochemical analysis of MPUC (n = 11) and conventional UC (n = 57) for MUC1 and sLeX to determine whether these factors immunolocalized. Dual immunofluorescence staining was also carried out to assess MUC1 and sLeX colocalization. We also performed Western blot analysis of Chinese hamster ovary cells misexpressing both recombinant epitope-tagged MUC1 and glycosyltransferases enabling sLeX biosynthesis. ResultsMPUC samples preferentially exhibited both MUC1 protein and sLeX carbohydrate expression on the stroma-facing membrane of carcinoma cells. Based on univariate analysis, MUC1 expression in that pattern was positively correlated with tumor extension, lymphovascular invasion, lymph node metastasis, disease stage, and relatively poor patient prognosis. A comparable sLeX expression pattern also correlated positively with tumor extension and nodal metastasis. Based on multivariate analysis, localization of MUC1 and sLeX on the stroma-facing side of the membrane was positively correlated with lymph node metastasis. ConclusionsOverall, our immunofluorescence findings as well as immunoprecipitation analyses of Chinese hamster ovary cell transfectants strongly suggest that MUC1 is a potential scaffold protein for sLeX carbohydrates in MPUC. Both MUC1 and sLeX may cooperatively contribute to MPUC histogenesis and clinicopathological characteristics.

MP48-03 INTRATUMORAL HETEROGENEITY OF ERBB2 AMPLIFICATION AND HER2 EXPRESSION IN MICROPAPILLARY UROTHELIAL CARCINOMA

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology II1 Apr 2017MP48-03 INTRATUMORAL HETEROGENEITY OF ERBB2 AMPLIFICATION AND HER2 EXPRESSION IN MICROPAPILLARY UROTHELIAL CARCINOMA Sumit Isharwal, Hongying Huang, Gouri Nanjangud, François Audenet, Ying-Bei Chen, Anuradha Gopalan, Samson Fine, Satish Tickoo, Gopakumar Iyer, Jonathan Rosenberg, Dean Bajorin, Harry Herr, Machele Donat, Guido Dalbagni, Bernard Bochner, David Solit, Victor Reuter, and Hikmat Al-Ahmadie Sumit IsharwalSumit Isharwal More articles by this author , Hongying HuangHongying Huang More articles by this author , Gouri NanjangudGouri Nanjangud More articles by this author , François AudenetFrançois Audenet More articles by this author , Ying-Bei ChenYing-Bei Chen More articles by this author , Anuradha GopalanAnuradha Gopalan More articles by this author , Samson FineSamson Fine More articles by this author , Satish TickooSatish Tickoo More articles by this author , Gopakumar IyerGopakumar Iyer More articles by this author , Jonathan RosenbergJonathan Rosenberg More articles by this author , Dean BajorinDean Bajorin More articles by this author , Harry HerrHarry Herr More articles by this author , Machele DonatMachele Donat More articles by this author , Guido DalbagniGuido Dalbagni More articles by this author , Bernard BochnerBernard Bochner More articles by this author , David SolitDavid Solit More articles by this author , Victor ReuterVictor Reuter More articles by this author , and Hikmat Al-AhmadieHikmat Al-Ahmadie More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1484AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Micropapillary urothelial carcinoma (MPUC) is a rare but an aggressive variant of urothelial carcinoma. Histologically, most of these tumors are associated with variable amounts of ″not otherwise specified (NOS)″ urothelial carcinoma. MPUC has been previously shown to be associated with ERBB2 amplification and HER2 protein overexpression. However, the status and distribution of these findings within MP and NOS components of MPUC have not been addressed. Therefore, we evaluated the ERBB2/HER2 expression in MP and NOS components by FISH and IHC. METHODS We identified 44 cases of MPUC that had tissue available for FISH and IHC at our institute, of which an NOS component sufficient for both FISH and IHC was identified in 37 cases. We followed the updated ASCO/CAP Guidelines for breast cancer and as such amplification was defined by a HER2/CEP17 ratio of ≥2.0 or > 6 copies of the gene and HER2 overexpression was considered with IHC scores of 2+ and 3+. RESULTS In urothelial tumors with both MP and NOS components (n = 37), ERBB2 amplification in MP and NOS components was present in 25 and 16 cases respectively. ERBB2 amplification was significantly higher in the MP component compared to NOS component within the same tumor (67.57% vs. 43.24%, p = 0.049). HER2 overexpression in MP and NOS components was present in 25 and 13 cases respectively. HER2 overexpression was significantly higher in the MP component compared to NOS component within the same tumor (67.56% vs. 35.13%, p = 0.012). In addition, ERBB2 amplification strongly correlated with HER2 overexpression in both MP (rho = 0.65, p<0.001) and NOS (rho = 0.74, p<0.001) components. In this cohort (n = 44), tumor stage and lymph node status were significant predictors for overall survival (p = 0.01, <0.001 respectively). However, ERBB2 amplification and HER2 overexpression in MP component were not associated with patients′ survival outcome (p=1.00, 0.75 respectively). CONCLUSIONS The majority of MPUC is associated with ERBB2 amplification and HER2 overexpression. In MPUC, ERBB2 amplification and HER2 overexpression were preferentially but not exclusively identified in MP component compared to NOS component. Our findings provide evidence for intratumoral heterogeneity of ERBB2 amplification and HER2 expression in MPUC. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e637-e638 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Sumit Isharwal More articles by this author Hongying Huang More articles by this author Gouri Nanjangud More articles by this author François Audenet More articles by this author Ying-Bei Chen More articles by this author Anuradha Gopalan More articles by this author Samson Fine More articles by this author Satish Tickoo More articles by this author Gopakumar Iyer More articles by this author Jonathan Rosenberg More articles by this author Dean Bajorin More articles by this author Harry Herr More articles by this author Machele Donat More articles by this author Guido Dalbagni More articles by this author Bernard Bochner More articles by this author David Solit More articles by this author Victor Reuter More articles by this author Hikmat Al-Ahmadie More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Intratumoral heterogeneity of ERBB2/HER2 expression in micropapillary urothelial carcinoma.

383 Background: Micropapillary urothelial carcinoma (MPUC) is a rare but an aggressive variant of urothelial carcinoma. Histologically, most of these tumors are associated with variable amounts of “not otherwise specified (NOS)” urothelial carcinoma. MPUC has been shown to be associated with ERBB2/HER2 amplification and protein overexpression. However, the status and distribution of these findings within the different components of tumors containing both MP and NOS urothelial carcinoma have not been addressed. Methods: We identified 44 cases of MPUC that had tissue available for FISH and IHC at our institute, of which an NOS component sufficient for both FISH and IHC was identified in 37 cases. We followed the updated ASCO/CAP Guidelines for breast cancer and as such amplification was defined by a HER2/CEP17 ratio of ≥ 2.0 or &gt; 6 copies of the gene and HER2 overexpression was considered with IHC scores of 2+ and 3+. Results: In urothelial tumors with both MP and NOS components (n = 37), ERBB2 amplification in MP and NOS components was present in 25 and 16 cases respectively. ERBB2 amplification was significantly higher in the MP component compared to NOS component within the same tumor (67.57% vs. 43.24%, p = 0.049). HER2 overexpression in MP and NOS components was present in 25 and 13 cases respectively. HER2 overexpression was significantly higher in the MP component compared to NOS component within the same tumor (67.56% vs. 35.13%, p = 0.012). In addition, ERBB2 amplification strongly correlated with HER2 overexpression in both MP (rho = 0.65, p &lt; 0.001) and NOS (rho = 0.74, p &lt; 0.001) components. In this cohort (n = 44), tumor stage and lymph node status were significant predictors for overall survival (p = 0.01, &lt; 0.001 respectively). However, ERBB2 amplification and HER2 overexpression in MP component were not associated with patients’ survival outcome (p = 1.00, 0.75 respectively). Conclusions: In MPUC, ERBB2 amplification and HER2 overexpression were preferentially but not exclusively identified in MP component compared to NOS component within the same tumor. Our findings provide evidence for intratumoral heterogeneity of ERBB2 amplification and HER2 expression in MPUC.

Micropapillary urothelial carcinoma: is molecular hair-splitting on target?

Urothelial carcinoma (UC) of the bladder has been well investigated in terms of pathogenesis pathways, natural history and tumor biology. Clinically relevant biomarkers including diagnostic, prognostic and predictive molecular markers have been defined in phenotype and genotype analysis beginning with the Cancer Genome atlas (TCGA) study reported in year 2014 (1). The recent 2016 WHO Classification of Tumors of the Urinary System and Male Genital Organs enumerates several histological variants such as the micropapillary, nested, microcystic, plasmacytoid, lymphoepithelioma-like, lipoid cell, clear cell, sarcomatoid and poorly differentiated types (2). Micropapillary urothelial carcinoma (MPUC), first described by Amin et al . in 1994 has generated considerable interest (3). This aggressive variant of UC has a characteristic morphology, aggressive clinical behavior, high propensity for metastasis to regional lymph nodes and distant organs resulting in shorter survival. Recent analysis of molecular, phenotype and microRNA (miRNA) profiles of this variant define unique features which may assist in early recognition and timely treatment (4).

Argininosuccinate Synthetase 1 Loss in Invasive Bladder Cancer Regulates Survival through General Control Nonderepressible 2 Kinase–Mediated Eukaryotic Initiation Factor 2α Activity and Is Targetable by Pegylated Arginine Deiminase

Loss of argininosuccinate synthetase 1 (ASS1), a key enzyme for arginine synthesis, occurs in many cancers, making cells dependent on extracellular arginine and targetable by the arginine-degrading enzyme pegylated arginine deiminase (ADI-PEG 20). We evaluated ASS1 expression and effects of ASS1 loss in bladder cancer which, despite affecting >70,000 people in the United States annually, has limited therapies. ASS1 loss was identified in conventional and micropapillary urothelial carcinoma, small cell, and squamous cell carcinoma subtypes of invasive bladder cancer, as well as in T24, J82, and UM-UC-3 but not in 5637, RT112, and RT4 cell lines. ASS1-deficient cells showed preferential sensitivity to ADI-PEG 20, evidenced by decreased colony formation, reduced cell viability, and increased sub-G1 fractions. ADI-PEG 20 induced general control nonderepressible 2-dependent eukaryotic initiation factor 2α phosphorylation and activating transcription factor 4 and C/EBP homologous protein up-regulation, associated with caspase-independent apoptosis and autophagy. These effects were ablated with selective siRNA silencing of these proteins. ASS1 overexpression in UM-UC-3 or ASS1 silencing in RT112 cells reversed these effects. ADI-PEG 20 treatment of mice bearing contralateral flank UM-UC-3 and RT112 xenografts selectively arrested tumor growth in UM-UC-3 xenografts, which had reduced tumor size, reduced Ki-67, and increased terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. This suggests that ASS1 loss occurs in invasive bladder cancer and is targetable by ADI-PEG 20.

Micropapillary urothelial carcinoma: is molecular hair-splitting on target?

Micropapillary urothelial carcinoma: is molecular hair-splitting on target?

High prevalence of TERT promoter mutations in micropapillary urothelial carcinoma.

Somatic activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the most common genetic alterations in urothelial carcinoma (UC) of the bladder and upper urinary tract. Little is known, however, about TERT-mutation status in the relatively uncommon but clinically aggressive micropapillary (MPC) variant. We evaluated the presence of TERT promoter mutations in MPC of the bladder and upper urinary tract. A retrospective search of our archives for MPC and UC with micropapillary features (2005-2014) was performed. All slides were reviewed to confirm the histologic diagnosis. Thirty-three specimens from 31 patients had FFPE blocks available for DNA analysis and were included in the study. Intratumoral areas of non-micropapillary histology were also evaluated when present. Samples were analyzed with Safe-SeqS, a sequencing error reduction technology, and sequenced using the Illumina MiSeq platform. TERT promoter mutations were detected in all specimens with pure MPC (18 of 18) and UC with focal micropapillary features (15 of 15). Similar to conventional UC, the predominant mutations identified occurred at positions -124 (C228T) (85%) and -146 (C250T) (12%) bp upstream of the TERT ATG start site. In heterogeneous tumors with focal variant histology, intratumoral concordant mutations were found in variant (MPC and non-MPC) and corresponding conventional UC. We found TERT promoter mutations, commonly found in conventional UC, to be frequently present in MPC. Our finding of concordant intratumoral mutational alterations in cases with focal variant histology lends support to the common oncogenesis origin of UC and its variant histology.