Clonal Origin Of Multifocal Clear Cell Renal Cellcarcinoma Studied By Fluorescence In Situ Hybridization

Objective: Clear cell renal carcinoma(75%) is the most common type of neoplasm that arise in the kidney, at present nephron sparing surgery(NSS) is carried out extensively. But because of multifocal clear cell renal cell carcinoma, local recurrence after NSS is possible. Some researches revealed that the chromosome 3p deletion in clear cell renal cell carcinoma is widely existed, and the deletion showed little relationship with stage of the tumor. In this study, by comparing the chromosome 3p deletion using fluorescence in situ hybridization, the clonal origin relationship of primary tumors and satellite tumors are speculated.Materials and Methods: A total of 36 tumors from 18 patients with multifocal clear cell renal cell carcinomas were investigated, and the samples used are the formalin-fixed, paraffin-embedded tissue blocks. Dewaxing, rehydration and digestion process are organized for the 4-μm tissue sections, the tissue sections were hybridized with CEP 3 SpectrumOrange DNA probe and TelVysion 3P SG DNA probe, and the markers of D3S4559 microsatellite were detected. By counting the signal, the conditions of the chromosome 3p deletion in the samples are analyzed.Results: FISH analysis was done on 36 tumors from 18 patients by CEP 3 SpectrumOrange DNA probe and TelVysion 3P SG DNA probe. 3p deletion was observed in 28 tumors (78%).16(89%)cases show the chromosome 3p deletion in the primary tumors or satellite tumors ; 2 cases(11%)show no deletion in the primary tumors or satellite tumors. Tumors from 13 cases (72%) showed similar chromosome 3p deletion patterns, and tumors in 5 cases (28%) showed discordant chromosome 3p deletion patterns. Conclusion: Chromosome 3p deletion are existed in most of multifocal clear cell renal cell carcinomas, and most of primary tumors and satellite tumors have the same 3p deletion. Our data suggest that majority of multifocal clear cell renal cell carcinomas have a common clonal origin. In order to make a conclusive experimental result, more cases that meet the multifocal clear cell renal cell carcinoma are needed.