[998] Clinicopathological Study of Urothelial Carcinoma (UC) of the Renal Pelvis (RP): A Proposal for New pT3 Criteria

T Tsuzuki, N Sassa, M Fukatsu, T Fujita, A Katsuno, T Nishikimi, R Hattori, M Gotoh. Nagoya Daini Red Cross Hopital, Nagoya, Japan; Nagoya University, Nagoya, Japan; Komaki, Komaki Municipal Hospital, Japan; Chyukyo Hospital, Nagoya, Japan; Okazaki Municipal Hospital, Okazaki, Japan

Background: UC of the RP is thought to have a better prognosis than UC of the ureter. UC of the RP is characterized as stage pT3 when the tumor invades beyond the muscularis into the peripelvic fat or renal parenchyma. However, both general pathologists and GU pathologists often have difficulty differentiating parenchymal invasion from ductal spreading in the collecting ducts. Therefore, some cases with ductal spreading but without parenchymal invasion could be misclassified as “pT3”, which may indicate a better prognosis for UC of the RP.
Design: This study consisted of patients who underwent radical nephroureterectomy for UC of the RP. All cases were reviewed without clinical information by one pathologist (T.T.). We classified pT3 cases into the following four groups based on the extent of UC: pT3a, UC extended into the renal medulla; pT3b, UC extended into the renal cortex; pT3b, UC with peripelvic fat invasion; pT3d, pT3a or pT3b cases with UC peripelvic fat invasion. The pT stage and other parameters (tumor necrosis (TN), lymph-vascular invasion (LVI), nuclear grade (1973 WHO) (NG), and presence of CIS) were recorded.
Results: This study included 246 patients (177 males, 69 females; age range 33-94 years, mean 66.7 years). The pT stage and overall 5-year survival (OS) are listed.

pT stage and 5-year OS

	Number	%	OS
pTa and/or pTis	88	35.6	98.4
pT1	24	9.7	84.0
pT2	12	4.9	81.8
pT3a	52	21.1	89.0
pT3b	17	6.9	42.4
pT3c	5	2.0	0
pT3d	30	12.1	13.6
pT4	19	7.7	0

There was a statistically significant difference between pT3a and the other pT3 subtypes (pT3b, pT3c, and pT3d) (p<0.001). However, there were no statistically significant differences between pT3b, pT3c, pT3d, and pT4. In a univariate analysis, the presented pT classification, TN, LVI, and NG were statistically significant (p<0.001). In a multivariate analysis, the presented classification (p=0.0001, HR: 1.459), TN (p=0.012, HR: 2.586) and LVI (p=0.038, HR: 2.677) were statistically significant.
Conclusions: Our results suggest pT3b, pT3c, and pT3d should be classified as true pT3 and that pT3a should be classified as pT1 or pT2. We believe this proposed classification is simple and easy to apply, even for general pathologists. It is important to determine the appropriate pT stage in order to predict the prognosis of patients.
Category: Genitourinary (including renal tumors)

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 81, Wednesday Morning