Purpose: To evaluate the prognostic impact of the histological expression of CD133 in renal cell carcinoma (RCC).
Methods: From 1992 to 2009, 142 consecutive patients underwent radical nephrectomy or partial nephrectomy for RCC. All cases were reviewed by a single pathologist and then subjected to analysis of the immunohistochemical expression of CD133 using tissue microarray. Several clinical and pathological variables were also evaluated.
Results: The median postoperative follow-up was 44 months. Of the 142 immunostained RCC specimens, 77 (54%) showed low and 65 (46%) high expression of CD133. Expression of CD133 was associated with clinical stage (P = 0.05), lymph node involvement (P = 0.03), metastatic disease (P = 0.02) and MVI (P = 0.03). Among other variables, clinical stage, necrosis and metastasis were associated with disease-specific survival (DSS) and progression-free survival (PFS) on univariate analysis. The 5-year PFS rates in patients who provided specimens with high and low expression of CD133 were 83 and 66%, respectively (P = 0.01). It was observed that the 5-year DSS for patients who provided specimens with high and low expression of CD133 was 90 and 71%, respectively (P = 0.003). Multivariate survival analysis showed that patients in the CD133 low-expression group had a higher probability of disease progression (HR 3.4, P = 0.02) and a higher probability of death from cancer (HR 2.4, P = 0.01).
Conclusions: Immunohistochemical expression of CD133 had an impact on survival in patients with RCC, which shows that CD133 might be a useful tool for risk stratification. Low expression of this marker remained as an independent predictor of poor DSS and PFS.