A recent study led by Dr. Naik-Mathuria and many pediatric surgical oncology colleagues has shed light on the management and outcomes of children with Wilms Tumor (WT) complicated by inferior vena caval (IVC) thrombus. The study, which reviewed data from 2009 to 2019, aimed to provide a contemporary perspective on this condition, considering the advancements in treatment approaches.
Wilms Tumor is a common kidney cancer in children, and the presence of IVC thrombus adds complexity to its management. The most extensive series of patients with this complication was published nearly two decades ago, making it essential to gather up-to-date information on outcomes. The study found that neoadjuvant chemotherapy has become a widespread practice in managing these patients, but its impact on outcomes remained largely unreported until now.
The retrospective analysis included 124 patients, with 81% of them having favorable histology (FH) and 52% being at stage IV. The location of IVC thrombus varied, with 43% being infrahepatic, 26% intrahepatic, 11% suprahepatic, and 19% extending into the cardiac region. Notably, neoadjuvant chemotherapy using a 3-drug regimen was administered to 82% of the patients, followed by post-resection radiation in 90% of cases.
The study revealed that the overall regression rate of the thrombus level was 45%, with the suprahepatic location showing the best response at 62%. Encouragingly, cardiopulmonary bypass (CPB) could potentially be avoided in 67% of cases. Moreover, the peri-operative complication rate was significantly lower following neoadjuvant chemotherapy compared to upfront surgery (25% vs. 55%, P=0.005). While CPB was not associated with higher complications, its role in reducing thrombus-related risks warrants further investigation.
In terms of survival outcomes, the two-year event-free survival (EFS) was an impressive 93%, with an overall survival (OS) rate of 96%. Patients with favorable histology had even better outcomes, with an OS rate of 98% compared to 82% for cases with unfavorable histology/anaplastic tumors (P=0.73). The study also found that incomplete resection or the presence of viable thrombus cells did not significantly impact EFS or OS, suggesting that complete thrombectomy may not always be necessary.
The study's conclusions highlight the success of multimodal therapy in achieving excellent outcomes, even in cases of advanced-stage disease and cardiac extension. Neoadjuvant chemotherapy emerged as a valuable approach in reducing the need for CPB during resection, while the importance of complete thrombectomy may be reconsidered.
This valuable study provides valuable insights into the management and outcomes of children with Wilms Tumor and inferior vena caval thrombus. Surgeons treating these patients can draw upon these findings to optimize their strategies, incorporating neoadjuvant chemotherapy and tailoring thrombectomy approaches based on individual patient characteristics. With further research and refinement of treatment protocols, the prognosis for these young patients continues to improve.
Congratulations, Dr. Naik-Mathuria!