Under-reporting of carcinoma in situ in patients with high-grade papillary non–muscle-invasive bladder cancer

Abstract

Introduction: Patients with high-grade Ta/T1 NMIBC often have concomitant carcinoma in situ (CIS). However, the rate is variable, and pathologists may not examine every bladder biopsy once a high-grade papillary lesion is identified. Newer drugs for patients with Bacillus Calmette-Guérin–unresponsive NMIBC, such as nadofaragene firadenovec-vncg (ADSTILADRIN®), have a label indication for those with CIS ± papillary tumors. Therefore, failure to report CIS may impact access to therapy. We studied the incidence of CIS in a cohort of patients with high-grade Ta/T1 NMIBC in a private practice setting. Methods: Pathology specimens from transurethral resections in 2024 from patients at Arkansas Urology with a diagnosis of high-grade papillary NMIBC without CIS were reviewed by one pathologist (AC), with review of all bladder biopsies and incidence of CIS reported. Results: There were 328 patient samples reviewed. Mean patient age was 73 years (range, 47-93 years), and 80.5% were male. ICD-10 codes indicated bladder malignancy (C67.x) or hematuria (R31.0), but only 2 cases referenced CIS (D090). Overall, 84 cases (26%) showed CIS on re-review. Among the 5 pathologists who initially reviewed the cases, CIS-positive rates varied from 0 (0/9) to 67% (20/30). Conclusion: Based on this single-center study, approximately one-quarter of high-grade Ta/T1 specimens may have initially unreported CIS. Good communication between urologist and pathologist is essential to request a specific ruling out of CIS in all bladder fragments, as a diagnosis of CIS in addition to high-grade papillary disease may impact therapeutic options for the patient according to FDA labels and NCCN guidelines.