A Study of Microsatellite Instability of Upper Urinary Tract Transitional Cell Carcinoma / 대한비뇨기과학회지

ABSTRACT

PURPOSE: The objective of this study was to evaluate the role of microsatellite instability (MSI) in upper tract transitional cell carcinomas (TCC). MATERIALS AND METHODS: A total of 48 surgically treated renal pelvis and ureteral TCC patients were included in this study. MSI was determined by polymerase chain reaction (PCR) for amplification of the microsatellite sequences at mononucleotides BAT25 and BAT26, and dinucleotides D17S250, D2S123 and D5S346 in DNA and hMLH1 protein, p53 and Ki-67 expressions were determined by immunohistochemistry on retrieved tumor tissue. RESULTS: Twenty seven (56.2%) and 21 (43.8%) of the 48 patients had renal pelvis and ureteral TCC, respectively. Eighteen (37.5%) and 30 (62.5%) patients had superficial and invasive TCC, according to the pathological stage, while 24 each (50%) had low and high grade TCC, respectively. MSI was observed in 20.8% of tumors at mono-MSI and 22.9% at di-MSI. MSI-high and -low (instability >2 and <2 loci, respectively) were observed in 12.5 and 22.9%, respectively. From a univariate analysis, age, stage, tumor grade, tumor recurrence and the expressions of hMLH1 and Ki-67 were not related to MSI. However, in recurred cases, infiltrative tumors had 100% MSI compared to superficial tumors, and the expressions of p53 and Ki-67 were related to the stage and tumor grade, respectively (p<0.05). CONCLUSIONS: These results suggest that MSI may occur in upper tract TCC, as observed in other tumors. MSI was more frequently expressed in ureteral than renal pelvis tumors. However, MSI was not correlated with stage or grade, but was significantly correlated with the stage in recurred cases; and the expressions of p53 and Ki-67 were related to the stage and tumor grade.