Clinicopathological Analysis of Patients with Non-muscle-invasive Bladder Cancer: Prognostic Value and Clinical Reliability of the 2004 WHO Classification System

Abstract

Objective: The aim of this study was to clarify the prognostic value and clinical reliability of the 2004 World Health Organization classification system of non-muscle-invasive bladder cancer. Methods: Between January 1995 and November 2010, 153 patients were diagnosed with nonmuscle-invasive bladder cancer. We used a substage system that discerns T1-microinvasive (T1m, 42 patients) and T1-extensive-invasive (T1e, 37 patients) cancers. Results: There were 2 (1.3%), 89 (58.2%) and 62 (40.5%) cases of Grade 1 -3 urothelial carcinoma, respectively, on the basis of the 1973 World Health Organization classification system. Of these, 37 (24.2%) and 116 (75.8%) were graded as low and high on the basis of the 2004 World Health Organization classification system. All of the cases with progression (15 patients) were diagnosed as high grade at the time of primary transurethral resection of the bladder tumor. Based on the Kaplan -Meier analysis, the 2004 World Health Organization classification system accurately predicted tumor recurrence (P ¼ 0.029) and progression (P ¼ 0.031). The 5-year recurrence-free survival rates in patients with low-grade and high-grade tumors were 68.7 and 47.1%, and the 5-year progression-free survival rates were 100 and 89.0%, respectively. In the high-grade T1 cases, the substage (T1m or T1e) was a significant predictor of tumor recurrence (P ¼ 0.001) and progression (P ¼ 0.020). Conclusions:The 2004 World Health Organization classification system accurately predicts the risk of recurrence in primary non-muscle-invasive bladder cancer cases and has the same accuracy when predicting the risk of progression as the 1973 World Health Organization classification. Furthermore, the substaging system for high-grade T1 tumors is useful in predicting both recurrence and progression.

Staging of bladder cancer

“…subsequently proposed a 2‐mm cut‐off and, more recently, a 0.5‐mm cut‐off, which is pragmatically equivalent to one high‐power field, was proposed by van der Aa et al . The 0.5‐mm/one high‐power field cut‐off has been shown to be widely feasible and, in the majority of studies, correlated with outcome . Alternatively, Lopez‐Beltran et al .…”

“…44 Amin et al and McKenney et al subsequently proposed a 2-mm cut-off and, more recently, a 0.5-mm cut-off, which is pragmatically equivalent to one high-power field, was proposed by van der Aa et al 40,42,43 The 0.5-mm/one high-power field cut-off has been shown to be widely feasible and, in the majority of studies, correlated with outcome. 42,[45][46][47][48][49][50] Alternatively, Lopez-Beltran et al proposed the cut-off to be 20 infiltrating tumour cells within the lamina propria rather than a linear measurement. 41 Specifically, with regard to papillary urothelial carcinoma, Lawless et al compared tumours with stalk-only invasion and focal tumour base invasion to tumours with extensive tumour base invasion, and found significantly worse outcomes in patients with extensive invasion.…”

Dataset for reporting of carcinoma of the urethra (in urethrectomy specimens): recommendations from the International Collaboration on Cancer Reporting (ICCR)

“…It is recommended that the tumour should be reported as high‐grade when variant histology such as this is present, despite the bland cytology, in order to reflect its biological behaviour . It is also evident that studies that graded invasive urothelial carcinoma using the 1973 WHO have demonstrated its prognostic significance . The WHO 2016 recommends grading of invasive urothelial carcinoma using criteria that are the same as in WHO 2004, recognising that the vast majority of tumours will be high‐grade (this recommendation is endorsed by the ICCR).…”

“…91 It is also evident that studies that graded invasive urothelial carcinoma using the 1973 WHO have demonstrated its prognostic significance. 82,84,92,93 The WHO 2016 recommends grading of invasive urothelial carcinoma using criteria that are the same as in WHO 2004, recognising that the vast majority of tumours will be high-grade (this recommendation is endorsed by the ICCR). If an alternative grading system is used concurrently, this should be indicated.…”

Classification of urothelial tumors

“…Certains considèrent que la classification OMS/ ISUP2004 est supérieure à celle de l'OMS 1973 pour l'appréciation de la récidive et de la progression des tumeurs de vessie [10][11][12][13]. D'autres articles ne notent pas de diffé-rence significative entre les deux classifications pour évaluer l'évolution des tumeurs qui n'infiltrent pas la musculeuse [14,15].…”