Survival outcomes of different Histopathological Subtypes and stages of Wilms Tumor treated following SIOP 2001 Protocol, Children Hospital Lahore, 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. A survival outcome of different subtypes is excellent depending upon the stage of patient. In developed countries, overall survival and disease free survival is excellent due to early presentation and closer follow up. Methods: A retrospective study conducted at the Pediatric Hematology/Oncology department, Children Hospital, Lahore. All diagnosed WT cases from 1st January 2014 who completed their treatment before 31st December 2018 were included. Entire management was based on SIOP 2001. Patients presenting before nephrectomy received four cycles of pre-operative chemotherapy depending upon the clinical stage. After nephrectomy, postoperative chemotherapy regimen was based on stage, risk stratification and metastatic status of the patient. Survival outcome of different histopathological subtypes and stages was determined via Kaplan-Meier survival analysis and p-value was calculated via log rank test. Results The mean age of 93 children was 44.4 months with predominance of males (55.9%) and more commonly found in right sided kidney (55.9%). Majority patients completed the entire course of treatment (77.4%). The overall survival of all histological subtypes and stages was 77.4% and 77.1% and disease free survival was 88.2% and 89.4% respectively, at 48 months follow up. Our study showed that febrile neutropenia is major culprit affecting treatment outcome. Conclusions The advanced stage presentation is quite typical in developing nations and contributes towards decreased OS and DFS 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 low middle income class country and uneducated background, majority patients completed the entire course of treatment and relapse was fairly less. The perks of current study are that our hospital is the only pediatric tertiary care centre in Lahore, which have investigated a variety of parameters influencing the course of WT treatment over four-year time period.