Wilms tumor: five-year tumor-free survival on a modified SIOP protocol from an Indian university hospital

Wilms Tumor in India: A Systematic Review

Shyam SrinivasanBackground  Cure rates of childhood malignancies are inferior in India compared with upper-middle-income countries. There is paucity of quality data addressing outcome of childhood Wilms tumor (WT) from India. This systematic review was conducted to assess the disease trends, treatment strategies, and outcome indicators in WT across India. Materials and Methods  We conducted a systematic search of MEDLINE, Google Scholar, and SCOPUS database, and additionally screened International Society of Pediatric Oncology conference abstracts. Data concerning WT or nephroblastoma published from India were extracted. Results  A total of 17 studies containing 1,170 patients were included in this review. Ninety-four percent of the studies were published after the year 2010. Advanced stage (III and IV) disease was seen in 46% of included patients. In seven studies, patients underwent a pretreatment biopsy before commencement of therapy. A hybrid approach consisting of "surgery first" in a selected subset and "neo-adjuvant chemotherapy" in all others was the most common treatment strategy adopted in half of the studies. The overall survival ranged between 48 and 89%. Key prognostic factors influencing survival across studies included increased tumor volume, metastatic disease, and unfavorable histology. Nonrelapse mortality (2.7-8.5%) was noted to be high. Conclusion  Substantial proportion of children with WT from India present with advanced stages of the disease. Despite several limitations, the current systematic review showed a modest survival among Indian children with WT. Adopting strategies through collaboration to ensure early access to expert care along with involvement of social support team to improve compliance may further improve survival of WT in India.

Postchemotherapy tumor volume as a prognostic indicator in Wilms tumor: A single-center experience from South India

BACKGROUND

Optimal risk stratification is the key to minimizing relapse and toxicity in children with Wilms tumor (WT). The study evaluated poor tumor volume response to chemotherapy as a risk factor that predicts relapse.

PROCEDURE

Children with WT who were treated between 2005 and 2020 at the center were analyzed. Tumor volumes at the time of diagnosis and after preoperative chemotherapy were calculated from cross-sectional imaging. The International Society of Paediatric Oncology (SIOP)-WT-2001 protocol was used for treatment. The area under a receiver operating characteristic curve was estimated to ascertain the ability of tumor volume to predict relapse.

RESULTS

Ninety-five patients with a median age of 40 months were included. A postchemotherapy tumor volume cutoff of 270 ml was ascertained to have the best predictive value for relapse. Patients with a tumor volume of <270 ml following preoperative chemotherapy had a better 3-year event-free survival (EFS) than those with a tumor volume of ≥270 ml (89.8% ± 4.0% vs. 57.4% ± 12.5%, p = .001). The data demonstrated that a tumor volume of ≥270 ml after chemotherapy was associated with an increased risk of relapse (hazard ratio [HR]: 5.3, p = .006). The EFS in patients with an epithelial or stromal type of histopathology was not affected by the tumor volume response (p = .437). Conversely, patients with other types of intermediate-risk histopathology who had a poor tumor volume response had an inferior survival (3-year EFS 51.4% ± 18.7%, p = .001).

CONCLUSION

A postchemotherapy tumor volume cutoff of ≥270 ml emerged as a strong predictor of relapse in a low- and middle-income country (LMIC) center study of WT treated with the SIOP protocol.

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.

Predictors of treatment outcome of Wilms Tumour in low-income country; single centre experience from Pakistan

BACKGROUND

Wilms tumor (WT) represents around 85% of pediatric renal tumors. In high-income countries, 5-years survival of WT is above 90% but survival in developing countries is inferior.

OBJECTIVE

To identify the predictors of treatment outcome of WT in a developing country.

METHODS

A retrospective study conducted at the pediatric oncology department, Combined Military Hospital Rawalpindi, Pakistan. All newly diagnosed WT cases from 1st January 2012 who completed their treatment before 31st August 2019 were evaluated. Treatment was based on SIOP Wilms Tumour 2001/UK version 5. Patients presenting before nephrectomy received pre-operative chemotherapy. The postoperative chemotherapy regimen was decided according to the stage, risk stratification and metastatic status of the patient.

RESULTS

Data of 84 cases, including 40 (47.6%) males and 44 (52.4%) females was analyzed. The mean diagnostic age was 38.87 ± 28.66 months and 68 (81%) cases were less than five years of age. The commonest presenting features were abdominal mass in 75 (89.3%) cases. The right kidney was affected in 43 (51.2%) cases. Stage I disease was documented in 27 (32.1%) cases, stage II in 25 (29.8%), stage III in 13 (15.5%), and stage IV in 17 (20.2%) cases. In univariate analysis, advanced stage (P = < 0.001) and metastatic disease (P=< 0.001) adversely affected the treatment outcome. Multivariate analysis demonstrated that advanced stage WT was associated with the worst outcome (P= < 0.05). Four (4.8%) cases had treatment-related mortality (TRM). With a median follow-up time of 28.26 ± 23.03 months, OS and EFS were 66 (78.6%) and 63 (75.0%) respectively.

DISCUSSION

Delayed presentation with advanced-stage metastatic disease is quite common in the developing courtiers and is the major contributor to decreased EFS and OS. In the present study, 20.2% cases had metastatic disease, which is similar to reported from other developing countries. OS decreased from 92.6% in stage I to 47.1% in stage IV disease (P=< 0.001) and EFS decreased from 92.6% in stage I to 43.8% in stage IV disease (P=< 0.001). Very similar results are reported by a regional study [17]. Results in stage I and II disease are comparable to documented in the western world and inferior in advanced-stage disease. The strength of the present study is that multiple factors, affecting the treatment outcome of WT over almost seven years period were evaluated.

CONCLUSIONS

Stage of the disease is the most important prognostic factor. Delayed presentation with metastatic disease has a poor outcome.

Childhood cancer in India

India has made significant improvement in childhood cancer services in last few decades. However, the outcome still remains modest as compared to global standards due to significant barriers in recognition, diagnosis and cure. Data regarding comprehensive childhood cancer burden in country is lacking due to low and urban predominant coverage of population-based cancer registry programs. The available data shows lower incidence of childhood cancer incidence especially in leukaemia and CNS tumours which may suggest poor awareness of caregivers and delayed diagnosis with many "missed cases". Incidence data are also skewed towards male preponderance which suggests gender bias in seeking healthcare. The childhood cancer services in India are predominantly restricted to few tertiary care centres in major cities. The outcome in major groups of cancer is complicated by delayed and more advanced stage of presentation and poor supportive care during intensive treatment. Treatment refusal and abandonment remains major hurdles. Last few decades saw development of dedicated paediatric oncology services and training programs in the country. The development of InPOG (Indian Paediatric Oncology group) for conducting collaborative trials will lead to adoption of uniform treatment protocols suited for the country. Financial support through the government promoted health insurance and holistic support through philanthropic organizations have improved treatment adherence and outcome. Moving forward, the focus should be on strengthening the cancer registries for capturing nationwide data, improving awareness of childhood cancer among caregivers and healthcare workers for early recognition and improving accessibility of childhood cancer care services beyond major cities.

Clinical outcomes of children with Wilms tumor treated on a SIOP WT 2001 protocol in a tertiary care hospital in south India

INTRODUCTION

Wilms tumor is the most common pediatric renal malignancy. While developed countries have had excellent survival, it remains poorer by comparison in developing countries. The aim was to analyze the clinical outcome of children with Wilms tumor managed in a developing country from 2004 to 2014 by the SIOP WT 2001 protocol.

METHODS

Fifty-nine children with Wilms tumor managed by a SIOP WT 2001 regimen from 2004 to 2014 were analyzed.

RESULTS

The median age at presentation was 36 months, and 59% were boys. The average size of the tumor at presentation was 523 mL. Inferior vena cava thrombus was present in 11, distant metastases in 18, and bilateral tumors in six. Preoperative chemotherapy was given to all children after a diagnostic core needle biopsy. Preoperative chemotherapy reduced the tumor size to a mean of 208 mL and resolved venacaval thrombus in eight. Fifty-five children underwent definitive surgery while two children died during preoperative chemotherapy and two remained inoperable. All surviving children received adjuvant chemotherapy with 17 receiving radiotherapy as well. The overall survival (OS) was 80% and the event-free survival (EFS) was 73% after a mean follow up of 42 months after completion of therapy.

DISCUSSION

The tumor volumes at presentation and the incidence of venous tumor thrombosis in our cohort were much higher than those reported from developed countries. The incidence of metastatic disease at diagnosis (30.5%) was significantly higher than the 10-12% reported in Western data, but similar to that reported from various developing countries (14.1-31%). The OS in our cohort was 80% and the EFS was 73% with there being no events after 28 months. Although the survival rate for localized disease is similar to that in developed countries, the OS for metastatic disease was significantly less (50% vs. 75%). We also found that using an upfront posterior flank core biopsy was safe and beneficial for differentiating Wilms tumor from other pediatric renal tumors that are less chemosensitive.

CONCLUSION

In a resource-restricted environment such as ours, the SIOP WT 2001 protocol has been found to show excellent results.

Is Pre-operative Chemotherapy Desirable in all Patients of Wilms' Tumor?

The timing and role of chemotherapy in the management of Wilms' tumor has long been the matter of debate, with different groups showing equally comparable and encouraging results. Over the last decade, however, both the ideol-ogies seem to be converging and the attempt has been to identify groups benefitting with pre-operative chemotherapy, as well as those, where upfront resection should be attempted. In this article authors intend to discuss pros and cons of both the strategies and their applicability in a resource poor setting in developing countries like India.

Management of Wilms Tumor: ICMR Consensus Document

Wilms tumor (WT) is the most common renal tumor of childhood. Although multidisciplinary care including surgery, chemotherapy and radiotherapy have greatly improved the survival rates in WT, there is a scope for further improvement in India and other resource-poor settings. In resource-limited settings, the majority of patients present with large tumors, which may either be unresectable or risky to resect; making preoperative chemotherapy followed by delayed surgery the preferred approach. Histology and staging are used for risk stratification. The imaging procedure of choice is Contrast Enhanced CT scan (CECT) of thorax/ abdomen and pelvis, which is to be done at presentation, as well as for re-evaluation. Surgery is the cornerstone of treatment in WT and Radical Nephroureterectomy and Lymph node sampling is the procedure of choice, to be performed at week 5 in Non Metastatic WT and week 7 in Metastatic WT. WT is an extremely chemosensitive and radiosensitive tumor. Preoperative chemotherapy for Non Metastatic WT consists of 4 wk of Vincristine /Actinomycin and 6 wk of Vincristine /Actinomycin/ Adriamycin for Metastatic WT, with post-operative chemotherapy depending on stage and histology. Radiation therapy is recommended mainly in Stage III and Stage IV WT, with other indications given in the text. Other recommendations, such as treatment of WT in special situations and for supportive care are also detailed in the text.

Function and size of the residual kidney after treatment of Wilms tumor

Long-term damage to the residual kidney is of concern in the survivors of Wilms tumor. Our objective was to evaluate the long-term glomerular function and size of the residual kidney in these patients. Twenty-nine survivors of Wilms tumor diagnosed between July 1999 and June 2004 were enrolled. The glomerular function was assessed by creatinine clearance, 99mTc DTPA radionuclide scintigraphy and 24-hour urinary protein. Renal size was evaluated by ultrasonography. Median age at diagnosis and at enrollment were 2.87 ± 1.8 (range: 0.5-7.5) and 7.9 ± 3.8 years (range: 2.5-18). Median duration of follow-up was 4.78 ± 2.6 years (range: 1-8.8). Evidence of renal dysfunction in the form of either function or size was identified in eight (27.6%) children. Six children had subnormal glomerular filtration rate and one had proteinuria. Subnormal size of the residual kidney was observed in one child. Age at diagnosis, stage, and duration elapsed after nephrectomy had no association with renal dysfunction (P >.05). Long-term follow up is crucial to identify clinical nephrotoxicity among survivors of Wilms tumor.