Discrepancy between clinical stage and pathological stage based on the tumor location of urothelial carcinoma: A hospital-based cancer registry in Japan.

Abstract

579 Background: Accurate staging in patients with urothelial carcinoma (UC) of the bladder (UCB) or the upper urinary tract (UTUC) is essential for planning the appropriate treatment strategy. Although an underestimation of the pathological stage may result in missing the opportunity to perform preoperative treatment, the actual rate of the discrepancy between the clinical and pathological stages in UC is not known. Methods: We used Hospital-Based Cancer Registry (HBCR) data in Japan to extract 3,747 cases of UCB and 6,831 cases of UTUC with cT1-4N0M0 that were diagnosed in 2012–2015, histologically confirmed, and treated with radical surgery. We excluded patients who received chemotherapy or radiotherapy and those with an unknown clinical or pathological stage. Results: The proportion of UCB patients whose pathological stage was up-staged was 25%, and that of the UTUC patients was 30%. Among the patients with cT1 at each tumor location, up-staging to muscle-invasive cancer occurred in 30.9% (UCB, n=1132: pT2, 21.6%; pT3, 7.9%; pT4, 1.5%) and 37.5% (UTUC, n=2526: pT2, 16.9%; pT3, 20.2%; pT4, 0.4%), respectively. In particular, in the group of UTUC patients with cT1, the proportion of up-staging for pT3 was higher than that in the group of UCB patients with cT1. In the cases with cTis, up-staging to muscle-invasive cancer occurred in 10.5% (UCB, n=391: pT2, 6.9%; pT3, 1.8%; pT4, 1.8%) and 18.5% (UTUC, n=872: pT2, 9.7%; pT3, 8.7%). In contrast, the proportion of down-staging to non-muscle-invasive cancer in cases with cT2 or higher was 12% in the UCB group (n=2291) and 15% in the UTUC group (n=504). Conclusions: Among UC patients, up-staging from non-muscle-invasive cancer to muscle-invasive cancer is relatively common, and the frequency of this discrepancy in clinical and pathological stages tends to be especially higher in UTUC patients. More accurate diagnostic imaging techniques and biomarkers are urgently needed for the identification of the appropriate UC candidates for preoperative treatment.