Introduction: We have previously found that NCAM+ALDH1+ cells contain the cancer stem like-cell population in Wilms` tumor. Thus far, the correlation between the histologic qualitative and quantitative characterization of this cell population and prognostic outcomes has yet to be investigated in Wilms`tumor.
Study objective: We examined the association between NCAM+ALDH1+ WT-CSC quantity and localization in WT specimens, and several clinical adverse outcomes.
Methods: Paraffin imbedded primary Wilms` tumor specimens from 20 patients were immuno-stained for NCAM and ALDH1. Intensity and positivity were determined by a pathologist, blinded to the clinical outcome. Clinical parameters and prognostic outcomes were determined based on the patients` medical records. The correlation between the histologic features and clinical parameters was assessed.
Results: Tumor recurrence was observed in 4 of the cases. Neo-adjuvant chemotherapy was used in 4 of the cases. The highest amount of double positive (NCAM1+ALDHA1+) cells was detected in both of these subgroups (5-25%). Over 50% double positive cells were detected in one case in whom following treatment with neo-adjuvant chemotherapy the tumor had recurred and consequently the patient succumbed to his illness. Additionally, the percentage of NCAM1+ALDH1+ cells was highest in the blastemal component of the tumors.
Conclusions: Quantity and specific localization of NCAM/ALDH1 positive cancer stem cells in Wilms-tumor correlates with treatment protocols that include neo-adjuvant chemotherapy and with tumor relapse. These results underscore the role of CSCs in disease progression. Additionally, localization of the NCAM1+ALDH1+ cells to Wilms` tumor blastema corresponds to our previous findings of the malignant nature of these Wilms` tumor blastemal CSCs
