Introduction and Objectives
Renal Cell Carcinoma (RCC) accounts for 2–3% of adult neoplasms and about 90% of all primary renal tumors. The progress in a diagnostic technologies (USG, CT, MRI) has led to the increase in T1a tumors diagnosis. One of the most promising new treatment methods of RCC is based on high temperature created by radiofrequency current circulating around needle probe introduced into the tumor. Beside the direct destruction of the cancer tissue the treatment may induce immunologic reaction against tumor antigens released from destroyed tumor cell. The aim of this study was to evaluate the impact of RFA on the peripheral blood lymphocyte subpopulations in patients with RCC at different time points after the RFA procedure.
Material and Methods
Blood was tested before, and 2, 4 and 6 weeks after the RFA in nine patients with renal cell carcinoma for the proportions of CD3+, CD3+HLA-DR+ (T-activated), CD3+CD4+ (T-helper), CD3+CD8+ (T-cytotoxic), CD56+CD16+ (Natural killer) cells. The blood was stained with fluorochromeconjugated monoclonal antibodies and percentages of cells expressing various markers were determined by flow cytometry. The tumors were diagnosed by contrast-enhanced CT. In all cases lesions were located peripherally and maximum diameter was not longer than 4 cm. In four cases RFA was performed in a single kidney (in all cases the contralateral kidney had been previously removed due to the RCC). The main reason to use RFA in these patients was the presence of medical contraindications to surgical treatment due to numerous concomitant diseases (hypertension, chronic obstructive lung disease, neurological diseases).
Our research is for the first time showing the changes in the proportions of major peripheral blood lymphocytes subpopulations (especially CD4+ and CD8+) in patients with RCC after thermoablation. In all the patients the changes were most pronounced two weeks after the RFA procedure. Interestingly, in 6 out of 9 patients the proportion of HLA-DR+ T cells was increased over the whole follow-up period. The proportion of the CD56+CD16+ cell cells was decreased in most of the patients. The extreme values were noted for CD8+ and CD56+16+ cells in two patients who had metastatic tumors in the remaining kidney (one of them had been only previously removed due to RCC).
Taking this into account, we suggest, that the additional therapeutic effect of an in vivo immunization against damaged tumor cells antigens could be important. If the ablated changes are small, at the initial stages of the tumor development, the stimulated increase of the immune response of the organism could be important.
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.