Predictors of survival outcomes of different histopathological subtypes and stages of Wilms tumor treated following the SIOP 2001 Protocol, Pediatric Tertiary Care Centre Pakistan experience

Abstract

Background: Wilms tumor is the most common pediatric renal neoplasm. Following preoperative therapy, various histological subtypes, risks, and clinical stages are determined. The survival outcome of different subtypes is excellent depending upon the stage of the patient. In developed countries, overall survival and disease-free survival are excellent due to early presentation and closer follow-up. Methods: A retrospective study was conducted at the Pediatric Hematology/Oncology Department, Children’s Hospital Lahore. All diagnosed WT cases from 1st January 2014 who completed their treatment before 31st December 2018 was included. Entire management was based on SIOP 2001. Patients presenting before nephrectomy received four cycles of preoperative chemotherapy depending upon the clinical stage. After nephrectomy, the postoperative chemotherapy regimen was based on the stage, risk stratification, and metastatic status of the patient. The survival outcome of different histopathological subtypes, and stages were determined via Kaplan-Meier survival analysis, and the p-value was calculated via a log-rank test. Results The mean age of the 93 children was 44.4 months. The majority of the males (55.9%) were affected and commonly noted in the right-sided kidney (55.9%). The majority of patients completed the entire course of treatment (77.4%). The overall survival of all histological subtypes and stages was 77.4% and 77.1%, respectively. Event-free survival was 88.2% and 89.4%, respectively, at the 48-month-follow-up. Our study showed that febrile neutropenia is a major culprit affecting treatment outcomes. Conclusions The advanced stage presentation is quite typical in developing nations and contributes to the decreased OS and EFS seen in different histological subtypes and stages. In our study, OS significantly dropped from 45.3% in stage III to 12.9% in stage IV disease (P < 0.001). Despite belonging to a low-middle-income class country and uneducated background, the majority of the patients completed the entire course of treatment, and relapse was fairly rare. The perks of the current study are that our hospital is the only pediatric tertiary care center in Lahore, which has investigated a variety of parameters influencing the course of WT treatment over four years.