Iyer, Gopa

The Dublin ISUP Consensus Conference covered the proceedings on the best practice recommendations on nonurachal glandular lesions of the urinary bladder, bladder diverticular cancers, and molecular features of bladder and urachal glandular lesions. The conference proceedings on urachal neoplasms (except for their molecular features) are published elsewhere. The rationale for convening this conference was the lack of structured and consented pathologic recommendations in these rare lesions. Consensus by participants was reached on the following statements: (1) intestinal metaplasia with dysplasia is considered to be a precursor to primary bladder adenocarcinoma; (2) dysplasia arising from cystitis glandularis should be reported in terms of focality (focal or nonfocal) and grade (low or high); (3) the term “adenocarcinoma” should only be used for carcinomas showing pure (nonurothelial) morphology and should not be used interchangeably in urothelial carcinoma with “glandular differentiation” because of the pathobiological differences and management implications; (4) the different histologic subtypes of bladder adenocarcinoma should be specified in the report; (5) immunohistochemistry has an ancillary role in the work up of bladder adenocarcinoma versus gastrointestinal or Müllerian-type adenocarcinomas; (6) lymphovascular invasion should be included as a parameter when reporting bladder adenocarcinoma; (7) representative or targeted sampling will be sufficient for bladder diverticulum resection specimens; and (8) molecular analysis in genomic profiling should be performed only in advanced or metastatic bladder and urachal adenocarcinomas for targetable therapy. This report on glandular (nonurachal) lesions of the bladder from the Dublin ISUP consensus conference will serve as a best practice recommendation and as a guide for future research on these relatively rare lesions.

This manuscript summarizes the first part of the proceedings of the 2023 Dublin ISUP Consensus Conference encompassing the best practice recommendations on the pathology of neoplasms of urachal origin. The rationale for convening this consensus conference was the lack of structured and consented histopathologic recommendations in these rare tumors. Consensus among the meeting participants (n=80) was reached on the following statements: (1) combination of gross, histologic, clinical and imaging findings with exclusion of secondary tumor metastasis are to be used in the diagnosis of urachal carcinoma; (2) the 2022 World Health Organization (WHO) separate criteria for the diagnosis of urachal adenocarcinoma and for nonglandular carcinoma should be applied; (3) specific elements are to be evaluated and recorded in the gross examination of resection specimens containing urachal tumors; (4) sampling considerations for resection specimens containing urachal tumors are advised; (5) participants are against using 5% or 10% cutoff for the extent of intraepithelial carcinoma in urachal mucinous cystic tumor of low malignant potential; (6) use of immunohistochemical markers for the differential diagnosis of urachal adenocarcinomas in transurethral resection (TUR) specimen is considered optional; (7) similar tumor classificatory (nosology) rules for carcinomas arising from bladder mucosa (eg, urothelial carcinoma, squamous cell carcinoma, and neuroendocrine carcinoma) should be applied for nonglandular urachal carcinomas; (8) a new staging approach other than the previously proposed systems should be designed for urachal carcinoma; (9) a system modifying the current Tumor-Node-Metastasis (TNM)/American Joint Committee on Cancer (AJCC) staging system for urinary bladder cancer is considered appropriate for a study in urachal carcinoma; and (10) several histologic elements are to be reported when diagnosing urachal carcinoma in TUR and resection specimens. This report from the Dublin ISUP consensus conference will serve as a practice recommendation for pathologists and as a guide for future standardized reporting protocols and research regarding urachal tumors. In addition, an international database for urachal cancers under the guidance of ISUP is being planned to be established to address pertinent issues in the pathology of urachal cancers.

PURPOSE Neoadjuvant chemotherapy (NAC) has proven survival benefits for patients with invasive urothelial carcinoma of the bladder, yet its role for upper tract urothelial carcinoma (UTUC) remains undefined. We conducted a multicenter, single-arm, phase II trial of NAC with gemcitabine and split-dose cisplatin (GC) for patients with high-risk UTUC before extirpative surgery to evaluate response, survival, and tolerability. METHODS Eligible patients with defined criteria for high-risk localized UTUC received four cycles of split-dose GC before surgical resection and lymph node dissection. The primary study end point was rate of pathologic response (defined as < ypT2N0). Secondary end points included progression-free survival (PFS), overall survival (OS), and safety and tolerability. RESULTS Among 57 patients evaluated, 36 (63%) demonstrated pathologic response (95% CI, 49 to 76). A complete pathologic response (ypT0N0) was noted in 11 patients (19%). Fifty-one patients (89%) tolerated at least three complete cycles of split-dose GC, 27 patients (47%) tolerated four complete cycles, and all patients proceeded to surgery. With a median follow up of 3.1 years, 2- and 5-year PFS rates were 89% (95% CI, 81 to 98) and 72% (95% CI, 59 to 87), while 2- and 5-year OS rates were 93% (95% CI, 86 to 100) and 79% (95% CI, 67 to 94), respectively. Pathologic complete and partial responses were associated with improved PFS and OS compared with nonresponders (≥ ypT2N any; 2-year PFS 100% and 95% v 76%, P < .001; 2-year OS 100% and 100% v 80%, P < .001). CONCLUSION NAC with split-dose GC for high-risk UTUC is a well-tolerated, effective therapy demonstrating evidence of pathologic response that is associated with favorable survival outcomes. Given that these survival outcomes are superior to historical series, these data support the use of NAC as a standard of care for high-risk UTUC, and split-dose GC is a viable option for NAC.

TPS4615 Background: While a standard approach to muscle-invasive bladder cancer (MIBC) management involves neoadjuvant cisplatin-based chemotherapy (NAC) followed by radical cystectomy (RC), up to 50% of pts recur with metastatic disease. Moreover, removal of the bladder has a significant impact on pts’ quality of life. Pathologic downstaging to non-muscle-invasive disease (<pT2) or complete response (pT0) at RC is associated with long-term survival benefit. Somatic DDR gene alterations were shown to be enriched in pts who were pT0 at RC following NAC in multiple retrospective analyses. We hypothesize that MIBC pts with somatic loss-of-function alterations within specific DDR genes and clinical responses to NAC can be uniquely managed with a bladder-sparing approach consisting of close cystoscopic and radiographic surveillance, avoiding the toxicities of definitive local therapy. Methods: A031701 is a multicenter phase II trial that will enroll 271 pts with T2-T4aN0/xM0 MIBC diagnosed within 60 days prior to enrollment. Multifocal MIBC, tumors >5 cm by cystoscopic assessment, and Bacillus Calmette-Guérin (BCG)-refractory disease (beyond standard induction and maintenance) are not allowed. Intravesical chemotherapy is allowed. Pts must be eligible for cisplatin chemotherapy. Eligible pts will receive either standard dose or dose dense gemcitabine and cisplatin chemotherapy (investigator’s choice) with simultaneous genetic sequencing of pre-treatment transurethral resection specimens. Pts whose tumors contain deleterious alterations in any 1 of 9 pre-selected DDR genes ( ERCC2, ERCC5, BRCA1, BRCA2, RECQL4, RAD51C, ATM, ATR, and FANCC) and who exhibit <T1 response on clinical restaging are eligible for organ-sparing management. Pts without deleterious DDR gene alterations or with >T1 disease after NAC will undergo RC or chemoradiation therapy (investigator/patient choice). The primary endpoint is 3-year event-free survival in DDR-altered pts who undergo bladder sparing, defined as the proportion of pts without BCG-unresponsive non-muscle invasive recurrences, any >T2 recurrences, or any metastatic recurrences. Secondary endpoints include clinical response rate (<cT1) in patients with deleterious DDR gene alterations following NAC, bladder-intact survival, overall survival, pT0 rate in DDR-altered pts who elect to undergo RC, pT0 rate in pts without DDR gene alterations, 3-year RC rate in pts with DDR gene alterations, and proportion of pts undergoing intravesical management for in-bladder recurrences. The study opened for enrollment in September 2018. Support: U10CA180821, U10CA180882. Clinical trial information: NCT03609216.

BACKGROUND: Immune checkpoint inhibitors are an important therapeutic option for urothelial carcinoma, but durable responses are achieved in a minority of patients. Identifying pre-treatment biomarkers that may predict response to these therapies or who exhibit intrinsic resistance, is of paramount importance. OBJECTIVE: To explore the prevalence of PD-L1 copy number alteration in urothelial carcinoma and correlate with response to immune checkpoint inhibitors. METHODS: We analyzed a cohort of 1050 carcinomas of the bladder and upper urinary tract that underwent targeted next generation sequencing, prospectively. We assessed PD-L1 protein expression, copy number status (next generation sequencing/FISH), and detailed treatment response. RESULTS: We identified 9 tumors with PD-L1 amplification and 9 tumors with PD-L1 deletion. PD-L1 protein expression was the highest in PD-L1 amplified tumors. Of the 9 patients whose tumors harbored PD-L1 amplification, 6 received immunotherapy with 4 deriving clinical benefit, and 2 achieving durable response. Of the 9 patients whose tumors had PD-L1 copy number losses, 4 received immunotherapy with 3 experiencing disease progression. CONCLUSIONS: PD-L1 copy number alterations may serve as potential biomarkers of response to immunotherapy in urothelial carcinoma patients, if validated in larger cohorts.

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder cancer focusing on important topics of high interest for the practicing surgical pathologist and urologist. This review represents the second of 2 manuscripts ensuing from this effort. Herein, we address the effective reporting of bladder cancer, focusing particularly on newly published data since the last 2016 World Health Organization (WHO) classification. In addition, this review focuses on the importance of reporting bladder cancer with divergent differentiation and variant (subtypes of urothelial carcinoma) histologies and the potential impact on patient care. We provide new recommendations for reporting pT1 staging in diagnostic pathology. Furthermore, we explore molecular evolution and classification, emphasizing aspects that impact the understanding of important concepts relevant to reporting and management of patients.

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder neoplasia with a focus on issues relevant to the practicing surgical pathologist for the understanding and effective reporting of bladder cancer, emphasizing particularly on the newly accumulated evidence post-2016 World Health Organization (WHO) classification. The work is presented in 2 manuscripts. Here, in the first, we revisit the nomenclature and classification system used for grading flat and papillary urothelial lesions centering on clinical relevance, and on dilemmas related to application in routine reporting. As patients of noninvasive bladder cancer frequently undergo cystoscopy and biopsy in their typically prolonged clinical course and for surveillance of disease, we discuss morphologies presented in these scenarios which may not have readily applicable diagnostic terms in the WHO classification. The topic of inverted patterns in urothelial neoplasia, particularly when prominent or exclusive, and beyond inverted papilloma has not been addressed formally in the WHO classification. Herein we provide a through review and suggest guidelines for when and how to report such lesions. In promulgating these GUPS recommendations, we aim to provide clarity on the clinical application of these not so uncommon diagnostically challenging situations encountered in routine practice, while also importantly advocating consistent terminology which would inform future work.