Proposal of sialyl Lewis x/a as prognostic biomarkers in clear cell renal cell carcinoma: A study on a cohort of 117 patients submitted to curative surgery

Abstract

Objective:

Metastatic recurrence has been reported to occur in 20–30% of patients with clear cell renal cell carcinoma (ccRCC). Although the prognosis of these patients is poor, no marker has been established to predict metastatic potential and/or prognosis. Therefore, we investigated membrane expression of sialyl Lewis x (sLe^x) and sialyl Lewis a (sLe^a), which is generally considered to be associated with cancer metastasis.

Materials and methods:

We enrolled 117 patients who underwent curative surgery for RCC and were pathologically diagnosed as ccRCC. Immunohistochemistry for sLe^x and sLe^a was performed to evaluate the signal intensity on the cell membrane. We statistically analysed whether membrane expression of sLe^x/sLe^a is correlated with clinicopathological parameters and prognosis.

Results:

Of the 117 patients, 72 were classified as sLe^x-positive and 44 as sLe^a-positive. The sLe^x-positive group had significantly shorter progression-free survival (PFS) and overall survival (OS) than the negative group. Similarly, the sLe^a-positive group had significantly shorter PFS than the negative group, and it showed a trend towards a reduction of OS, although it did not reach statistical significance, a fact that could be due to the small sample size.

Conclusion:

Both sLe^x and sLe^a could be possible future prognostic indicators in ccRCC.

Level of evidence:

Level 3