International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer

Introduction

  • Event: ISUP Consensus Conference on Current Issues in Bladder Cancer (2022)

  • Focus: Subcategorization of T1 bladder cancer

  • Collaborators: Antonio Lopez-Beltran, Maria R. Raspollini, Donna Hansel, among others

  • Purpose: Discuss clinical relevance and practical methods for categorizing T1 bladder cancer

Background on T1 Bladder Cancer

  • T1 Definition: Tumor invading subepithelial connective tissue (lamina propria) according to AJCC guidelines.

  • Clinical Significance: High aggressiveness with progression rates of 12%-54% to muscle-invasive disease.

  • Objective: To assess the need for T1 substaging in pathology reports and its relevance to oncological outcomes.

Conference Objectives

  1. Review literature on T1 bladder subcategorization (substaging).

  2. Evaluate current practices and methodologies for T1 subcategorization.

  3. Discuss the practical implications of various methods.

  4. Formulate recommendations for routine reporting of T1 subcategorization by pathologists.

Methodology

  • Survey Development: Circulated among ISUP members to gauge current methodologies and opinions.

  • Published Literature Review: Focus on studies from January 1994 to September 2022 assessing prognostic values of T1 subcategorization.

  • Discussion Format: In-person meeting for consensus on findings and recommendations.

Survey Findings

  • Response Rate: 155 responses from ISUP members.

  • Clinical Relevance: 60% of respondents support routine reporting of T1 substaging.

  • Preferred Methods: Preference for semiquantitative methods (31%) over histoanatomic methods (20%).

Key Questions and Results from Voting

  • Clinical Relevance: 96% agreed T1 substaging deserves reporting in pathology.

  • Method Preference: 37.3% favored quantitative methods (focal vs. nonfocal) while only 4% preferred histoanatomic methods.

  • Practicality: 59% in favor of mixed-method reporting.

Methods of T1 Subcategorization

  • Histoanatomic Methods: Use muscularis mucosae (MM) as a landmark.

    • Pros: Quick assessment.

    • Cons: Lack of identifiable MM in about 40% of specimens.

  • Semiquantitative Methods: Include assessments such as focal vs. nonfocal and maximum depth of invasion.

    • Pros: Higher prognostic value and better adaptability in practice.

    • Cons: Can be time-consuming and rely on precise specimen orientation.

Consensus at Conference

  • Clinical Relevance: Strong support for routine reporting of T1 substaging in daily pathology practice (96% agreement).

  • ISUP Endorsement: Strong recommendation to endorse the incorporation of T1 substaging in pathology reports (83% support).

  • Method Use: Although semiquantitative methods are preferred, no definitive consensus on a single preferred method was reached due to various limitations and practical concerns.

Conclusion

  • Current Status: There is a recognized need for T1 subcategorization in clinical practice due to its prognostic significance.

  • Future Direction: Further studies needed to establish a standardized methodology for T1 bladder cancer subcategorization to enhance prognostic evaluations and treatment decisions.