Factors responsible for stage III disease in patients with Wilms tumor enrolled in the JWiTS-2 study

A 10-year study of the outcome of wilms' tumor in central India and identifying practice gaps

Introduction:

Despite remarkable improvement in Wilms' tumor (WT) survival in Western world, sub-optimal outcome in resource-constrained settings is influenced by late presentation, larger size, and poor access to treatment. This prompted us to study the outcome at a tertiary care center and to identify the global and local practice gaps.

Materials and Methods:

A retrospective, observational study of WT was conducted from October 2009 to September 2019 at a tertiary care setting. Following the National Wilms' Tumor Study Group protocol, an upfront nephrectomy (unilateral resectable tumors) and preoperative chemotherapy (large/unresectable Stage I–III) were followed. The records were reviewed for demographics, stage, preoperative chemotherapy, predictive factors, and outcome. Survival curves were plotted by the Kaplan–Meier method, and analysis was performed using the SPSS software version 16.

Results:

One hundred and fifty-six children were included, median age was 4.1 years, with a male predominance. The most common stages of the presentation were II (40.4%) and III (34.6%). An upfront surgery was done in 27.6%, while remaining received preoperative chemotherapy. The median follow-up was 22 months, and the events included relapse in 46 (29.48%) and death in 54 (34.61%). The mean survival time was 45.7 (95% confidence interval [CI], 41.08–50.30). The 2-year overall survival was 65.38% (95% CI, 59–73), and the 2-year event-free survival was 36% (95% CI, 32–41). On comparison of the impact of preoperative chemotherapy, the survival estimates in Stages I–III and relapse rate were statistically similar, tumor size reduced significantly, and tumor spill was significantly lower (P < 0.05).

Conclusion:

WT is associated with late presentation, sub-optimal survival, and higher relapse in our setting associated with practice gaps related to the management including practice violations.

A nomogram for prediction of distant metastasis in children with wilms tumor: A study based on SEER database

INTRODUCTION

Accurate diagnosis of distant metastasis especially uncommon site of metastasis (UCM) in patients with Wilms tumor (WTs) is a demanding prerequisite for administration of appropriate therapy and achieving better survival outcome.

OBJECTIVE

To develop and validate a nomogram to predict probability of distant metastasis, and identify population demanded for rigorous imaging evaluations in children with WTs.

MATERIAL AND METHODS

Data of patients diagnosed with unilateral WTs and aged under 18 years old, were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The included patients were randomly allocated to the training and the validation cohort. Logistic regression analyses were performed to identify the independent risk factors and develop a predicting model of distant metastasis in WTs. The model-based nomogram was created and internally validated. Cut-off value of nomogram points was derived by using the receiver operating characteristics (ROC) curve analysis. Performance of the nomogram was evaluated in terms of discrimination, calibration and clinical usefulness.

RESULTS

A total 717 WTs patients were included in the study. Age at diagnosis (OR 1.173, 95%CI: 1.079-1.279), LND (OR 8.260, 95%CI: 2.837-24.814) and tumor size (OR 2.141, 95%CI: 1.378-3.329) were identified as the independent risk factors of distant metastasis in WTs. These three factors were incorporated to develop a model and a nomogram. The nomogram presented with good discriminative ability in the training cohort (C-statistics, 0.703) and validation cohort (C-statistics, 0.764), respectively. The calibration curves demonstrated adequate agreement between predicted probability and observed probability of distant metastasis. The nomogram also revealed its clinical usefulness by application of decision curve analysis (DCA). Cut-off value of nomogram points was 58 and its corresponding probability of distant metastasis was 0.22. The value was applied in risk stratification dividing the general cohort into high-risk and low-risk group.

DISCUSSION

Our study for the first time developed and validated a model and a visualized nomogram for individualized prediction of distant metastasis in WTs. C-statistics, calibration curves and DCA demonstrated good performance and clinical usefulness of the nomogram. Patients stratified as high-risk group were demanded for rigorous imaging evaluations to accurately identify UCM.

CONCLUSION

The nomogram, developed by incorporation of three independent risk factors, which are age at diagnosis, LND and tumor size, is used to facilitate individualized prediction of distant metastasis in WTs. Rigorous imaging evaluations are recommended for patients in high-risk group to identify UCM.