Analysis of prognostic factors of nephroblastoma in a Tunisian cohort

Nephroblastoma is the most common childhood abdominal malignancy. Many studies allowed a better understanding of prognostic factors and they permitted to adapt treatment according to a risk stratification approach.

To assess the most significant factors influencing the survival of patients presenting nephroblastoma.

We conducted a retrospective study over a 10-year period between 2001 and 2010 including 42 nephrectomy specimens, assessed in the pathology department of Salah Azaiz Institute, from all children diagnosed with nephroblastoma. The tumors were subdivided into histological subtypes and histological risk groups according to the SIOP-2001 classification. Statistical analyses were performed using the Kaplan-Meir and the Cox regression methods.

The median age was 38 months. The mixed type was the most common (40% of cases). The tumors were subdivided into intermediate histological risk group (81%) and high risk group (14%). The tumors were classified as stage I (38%), stage II (24%), stage III (9%), stage IV (17%) and stage V (12%). The four-year survival rate was 83% and the event free survival rate was 85%. Age, laterality, histological risk group, tumor volume, blastema volume, stage, capsular rupture and incomplete resection had a significant impact on survival. Predictive factors of relapse were: laterality, tumor volume, blastema volume, histological risk group, stage, capsular rupture and incomplete resection.

Histological type and stage were identified as the most important prognostic factors in nephroblastoma. Further large studies are needed to establish the impact of absolute blastemal volume.