Prognostic value of quantitative assessment of macrophage content (CD68+) in the peritumoral zone of clear cell renal cell carcinoma

AIM: To quantitatively analyze the macrophage distribution density (MF) of the peritumoral zone (PZ) of clear cell renal cell carcinoma (CCRCC) and determine the relationship of MF distribution density in PZ with clinical and morphological prognostic variables and postoperative survival of patients.

MATERIALS AND METHODS: The study included 52 patients with CCRCC, who had an average age of 56.7±0.8 years. Using monoclonal mouse antibodies for CD68 (clone PG-M1, DAKO), using an immunohistochemical method, macrophages were identified in the paraffin sections. The average amount of MF in the PZ was determined in three fields of view at ×400 magnification. For the PZ, the tissue was taken directly adjacent to the tumor to the conditionally unchanged kidney tissue.

RESULTS: The correlation analysis revealed that the density of the MF distribution in the CCRCC was interrelated with the stage of the disease (r=0.66; p=0.0001), size of the tumor node (r=0.52; p=0.0001), degree of anaplasia according to Fuhrman (r=0.80; p=0.0001), presence of metastases (r=0.62; 0.0001), and postoperative survival of patients (r=0.53; p=0.0001). However, there were no correlations with the gender (r=0.007; p=0.62) and age of the patients (r=0.03; p=0.83). With the number of MF in the PP <8.8, the cumulative proportion of survivors by the five-year term was 0.70 (70%). Moreover, when the number of MF in the PZ was ≥8.8, none of the patients lived to the five-year term, the cumulative proportion of survivors was 0 (log-rank-test, p=0.000001).

CONCLUSION: The density of MF distribution in PZ is interrelated with significant clinical and morphological parameters of CCRCC and is a predictor of the prognosis of five-year postoperative survival of patients. Thus, quantitative estimation of the number of MF in the PZ can be used in predicting the course of CCRCC along with the traditional classical forecasting factors.