Can CXCL13 be a prognostic marker in clear cell renal cell carcinoma?

Background: CXCL13, B-lymphocyte chemoattractant, has been associated with many diseases and cancers. One of the malignancies that CXCL13 has been investigated is clear cell renal cell carcinomas which are the most common subtype of renal cancers. Aims and Objectives: The aim of this study is to evaluate the immunohistochemical staining patterns of CXCL13 in clear cell renal cell carcinomas and to determine its relationship with pathological tumor stage, risk factors, and prognostic parameters. Materials and Methods: In this study, 99 patients who underwent partial/radical nephrectomy diagnosed with clear cell renal cell carcinoma were included. Four micron sections were taken from paraffin embedded blocks containing sufficient tumor and kidney tissue. Samples were immunohistochemically stained with CXCL13 antibody. During microscopic examination, CXCL13 positive stained cells in ten high magnification fields were counted and evaluated using a semiquantitative H score: 3 x strongly stained + 2 x moderately stained + 1 x weakly stained. The cut-off value was set as 40 for values between 0 and 300. The low and high stained groups were compared with prognostic parameters and risk factors. Statistics: The difference of continuous variables between the two groups was examined with the t test and the distribution of categorical variables with the Chi-square test. A value of P < 0.05 was considered to be statistically significant. Results: The number of lymphocytes stained with CXCL13 in the tumor was higher than in the normal kidney parenchyma (p = 0.07). Intratumoral lymphocytes were highly stained with CXCL13 in 57.5% of pT3 cases and 31.7% of pT1 cases. The amount of intratumoral lymphocytes stained with CXCL13 increased in advanced pathological stages (p = 0.05). Nonsmoking cases were mostly in the low staining group (p = 0.06). Conclusion: The relationship we found between advanced pathological stage and intratumoral CXCL13 staining in our study suggests that CXCL13 has a prognostic value in this cancer.