Objective To explore the expressions of PD-1 and PD-L1 in renal cell carcinoma and renal tissues adjacent to the tumor (0.5 cm, 1.0 cm and 2.0 cm), and provide the theoretical basis for selecting safe margin during partial nephrectomy surgery.
Methods A total of 60 renal cancer patients were selected, who underwent the radical nephrectomy and diagnosed renal clear cell carcinomas by postoperative pathology in urology department of the first affiliated hospital of Bengbu medical college between June 2014 and July 2015. General information and stages of patients were recorded. Normal renal tissues, cancer tissues and precancerous tissues with different distant to cancer were preserved. Immunohistochemistry staining was employed to detect the expressions of PD-1 and PD-L1 in renal tumors and corresponding adjacent tissues. The relationship between the expression of PD-1, PD-L1 and the safe margin of partial nephrectomy surgery was analyzed.
Results The expression of PD-1 and PD-L1 in renal clear cell carcinoma was significantly higher than that in adjacent renal tissues. In adjacent tissues, the expression levels were negatively related to the distance from the carcinoma. At the distance of 0.5 and 1.0 cm, the positive rate were significant difference (all
P<0.05). At the distance of 1.0 and 2.0 cm, the positive rate were not significant difference (
P>0.05). The expression of PD-1 and PD-L1 in renal clear cell carcinoma had no related to tumor stage at the distance of 1.0 cm from the edge of the tumor to adjacent tissues.
Conclusion The expressions of both PD-1 and PD-L1 were increased in renal clear cell carcinoma tissues than that in adjacent tissues, and furthermore the expressions in adjacent tissues were negatively associated with distance to the carcinoma tissues. A distance of 1.0 cm maybe an appropriate surgical margin for partial nephrectomy resections.