Clinical Significance of Circulating Tumor Cells and Ki-67 in Renal Cell Carcinoma

Abstract

Background: Renal cell carcinoma (RCC) is a common maligant tumor of the genitourinary system. We aimed to analyze the potential value of the metastasis-related biomarker, circulating tumor cells (CTCs) and proliferative marker Ki-67 in diagnosis of RCC. Methods: Data from 24 laparoscopic radical nephrectomy (RN) and 17 laparoscopic partial nephrectomy (PN) were collected in 2018. The number and positive rate of CTCs and circulating tumor microemboli (CTM) was obtained at three different time points in peripheral blood just before, immediately and one week after surgery. Ki-67 protein expression was evaluated in RCC tissue by immunohistochemistry. Results: No association between the number and positive rate of perioprative CTC and clinicopathological features was found, except for the statistically significant association between the preoprative CTC counts and tumor size. The CTC counts gradually decreased during the perioperative period, and at one week after surgery was significantly lower than that before surgery. Higher Ki-67 expression was significantly correlated positively with preoprative CTC counts. In addition, a higher Ki-67 express has been found in high CTCs group (CTCs ≥ 5). Conclusion: Our results suggest that surgical nephrectomy is associated with a decrease in CTC counts of RCC patients. CTCs can act as a potential biomarker for the diagnosis and prognostic of RCC. Careful and sufficient long-term follow-up is needed for patients with high preoprative CTC counts.