A 2-center review of histopathology of variants of upper urinary tract urothelial carcinoma and their impact on clinical outcomes

• Published in: Urologic oncology 2024-10, Vol.42 (10), p.333.e15-333.e20
• Main Authors: Giudici, N., Schoch, A., Genitsch, V., Rodriguez-Calero, A., Thalmann, G.N., Seiler, R.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Carcinoma, Transitional Cell - pathology; Carcinoma, Transitional Cell - surgery; Female; Histologic subtypes; Humans; Male; Middle Aged; Pathology review; Retrospective Studies; Upper tract urothelial Carcinoma; Ureteral Neoplasms - pathology; Ureteral Neoplasms - surgery; Urologic Neoplasms - pathology; Urologic Neoplasms - surgery; variant histology
• ISSN: 1078-1439; 1873-2496; 1873-2496
• DOI: 10.1016/j.urolonc.2024.05.005

•After pathological review variant histology is present in a third of UTUC.•Variant histology in UTUC as a high rate of concomitant CIS (71%).•Presence of variant histology is related to more aggressive tumor characteristics and associated with unfavorable outcomes.•Variant histology in UTUC is associated to a higher rate of extravesical recurrences and follow-up should include cross sectional imaging and cystoscopy. Similar to bladder cancer, about one third of upper tract urothelial carcinoma (UTUC) present variant histology (VH). We aim to evaluate the incidence, clinical characteristics and the impact on outcomes of VH in UTUC. We consecutively enrolled 77 patients treated between 2009 and 2022 by radical surgery for UTUC from a secondary and a tertiary referral center. A pathology review of all specimens was performed by 1 independent uropathologist for each center. We compared pure UTUC and UTUC with VH and the accuracy of endoscopic biopsy. Descriptive and comparative analysis was performed to assess the association with clinical characteristics and the Kaplan–Meier estimator to compare outcomes. Median follow-up after surgery was 51 months. VH was present in 21/77 (28%) patients and 4/21 (19%) patients had multiple variants. The most frequent VH was squamous 12/21 (57%), followed by glandular 7/21 (33%) and micropapillary 3/21 variants (14%). Neuroendocrine carcinoma was present in 2 patients. Nested variant was found in 1 patient. Muscle invasive tumor (≥pT2) was present in 30/56 (54%) patients with pure UTUC and in 18/21 (86%) patients with VH (P < 0.05). Presence of carcinoma in situ was seen in 24/56 (43%) patients with pure UTUC and in 16/21 (76%) with VH (P < 0.05). Cumulative 8/56 (14%) with pure UTUC had a nonintravesical recurrence (6 patients with local and 2 distant recurrence) compared to 8/21 (38%) (3 local, 3 nodal, 2 distant) in the subgroup with VH (P < 0.05). Opposite effect was noted for bladder recurrence: 60% for pure UTUC vs. 29% for tumors with VH (P < 0.05). Review of preoperative endoscopic biopsy did not show the presence of VH in any patients. Differences in outcomes did not reach significance: 3yr-OS 63% vs. 42% (P 0.28) and 3yr-CSS 77% vs. 50% (P 0.7). Almost a third of UTUC present VH. Presence of VH is related to more aggressive tumor characteristics and associated with unfavorable outcomes. Due to a higher rate of extravesical recurrences in UTUC with VH, Follow-up controls should include cross sectional imaging and c