Factors affecting lymph node sampling patterns and the impact on survival of lymph node density in patients with Wilms tumor: a Surveillance, Epidemiology, and End Result (SEER) database review

Prognostic impact of pre-referral tumor resection in unilateral Wilms tumor: A single-institute experience from a lower middle-income country

INTRODUCTION

The objectives of this study were to evaluate the prognostic impact of pre-referral surgical resection of Wilms tumor (WT) performed at non-oncology centers, and to strategize an improved care plan for this very curable pediatric tumor.

METHODS

In this study conducted in a large pediatric cancer center in Pakistan, we retrospectively reviewed the electronic medical records (EMR) of 149 patients with unilateral WT from September 2008 to August 2017. Based on treatment approach, patients were categorized into two groups: (i) pre-referral tumor resection (PTR: n = 75), and (ii) post-neoadjuvant chemo nephrectomy (PCN: n = 74).

RESULTS

The proportion of metastatic disease in PTR and PCN groups was 33.3% and 35.1%, respectively. In the PTR subset, median time to admission after PTR was 5 weeks (mean 11, SEM 2.8, range: 2-202) weeks, with 53.3% (n = 40) presenting more than 4 weeks after PTR. Twenty patients had no cross-sectional imaging prior to PTR and underwent surgery after abdominal ultrasound only. On baseline imaging at our center, 58.7% (n = 44) of the PTR group had radiologically evaluable disease (four metastases only, 19 local residual tumor only, 21 both localized tumor and visible metastases). Disease staging was uncertain in 23 patients because of no or inadequate histology specimens and/or lymph node sampling in patients with no evaluable disease. Statistically significant differences were recorded for the two subsets regarding tumor volume, extent and nodularity, renal vein and renal sinus involvement, lymph node status, tumor rupture and histopathologic features, and tumor stage, with a 10-year event-free survival (EFS) for PCN and PTR of 74.3% and 50.7%, respectively (p < .001). In the PTR group, EFS for those presenting within 4 weeks and later was 91.4% versus 15.0%, respectively (p < .0001).

CONCLUSION

Suboptimal pre-referral surgical intervention results in poor survival outcomes in unilateral WT. Our findings highlight the need for a comprehensive action plan for educating healthcare professionals engaged in WT diagnosis and referral process. PCN in a multidisciplinary team approach can reduce surgical morbidity and seems to be a better strategy to improve the survival rates in low-resource settings.

How to use the Surveillance, Epidemiology, and End Results (SEER) data: research design and methodology

In the United States (US), the Surveillance, Epidemiology, and End Results (SEER) program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data. This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field. Currently, the SEER program covers approximately half of the total cancer patients in the US. A growing number of clinical studies have applied the SEER database in various aspects. However, the intrinsic features of the SEER database, such as the huge data volume and complexity of data types, have hindered its application. In this review, we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database. Therefore, the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.

Critical elements of radical nephroureterectomy for pediatric unilateral renal tumor

Children with renal masses require surgical management to provide accurate surgical staging and skilled resection of the tumor. This document includes evidence-based recommendations for pediatric surgeons regarding the resection, staging, and proper nodal basin evaluation.

Number of lymph nodes sampled in SFCE/SIOP 2001 patients with Wilms tumour: Is the goal of more than six achievable?

AIM

The number of lymph nodes (LN) that should be sampled during nephrectomy for Wilms tumour (WT) remains controversial but of utmost importance for staging purposes. The aim of this French national retrospective study of patients enrolled in SIOPWT2001 trial was to analyse the number of LN sampled according to their site and to determine if the number of six asked by the International Society of Paediatric Oncology - Renal Tumour Study Group (SIOP-RTSG) UMBRELLA protocol is achievable.

METHODS

We reviewed the data collected on central pathology review forms from 2002 to 2014 for only unilateral WT. LN were divided whether they were clearly identified by surgeons at nephrectomy or only found by pathologists on the nephrectomy specimen.

RESULTS

A total of 539 patients (240 male/299 female) were included (458 localized/81 metastatic). Median age at surgery was 41.3 months [0-189]. The number of LN sampled was 0, 1-6, ≥7 and unknown in 69 (12.8%), 293 (54.3%), 160 (29.7%) and 17 (3.2%) cases, respectively. The number of patients with sampled LN were higher if LN were identified by both the pathologist and the surgeon (n = 231, 42.8%) (p = < .001). At least one invaded LN (LN+) was found in 66 patients (12.2%), more than half being found among patients having LN sampled by both pathologist and surgeon (p < .001). The mean number of identified LN was six if no LN+ was detected on final histological analysis, while it was 11 in case of LN+ (p < .001).

CONCLUSIONS

The aim of sampling more than six LN is achievable, but only with the active collaboration of both surgeons and pathologists.

Technical advances in the surgical management of Wilms tumors in children

Surgery is one of the cornerstones of Wilms tumor treatment. In this article, we present technical advancements that are finding their way into the armamentarium of pediatric cancer surgeons. We discuss the current approaches, challenges, opportunities, and future directions of minimally invasive surgery (laparoscopic and robotics), image-guided surgery, and fluorescence-guided surgery. Furthermore, we discuss the use of intraoperative ultrasonography, as well as the use of new techniques to improve the quality of lymph node sampling.

Nephron sparing surgery outcomes in Wilms' tumor: is it ready for primetime?

PURPOSE

Radical nephrectomy is the gold standard in Wilms tumor (WT) treatment and is combined with adjuvant treatment in early stage disease or performed after neo adjuvant therapy in advanced disease. With the development of novel adjuvant and neoadjuvant therapeutic strategies, there is increasing interest in organ preserving procedures in several adult malignancies. Potential long-term complications of living with a single kidney include hyperfiltration syndrome, hypertension, and fluid retention. If NSS (Nephron Sparing Surgery) were to be adopted for the treatment of WT it would be necessary to preserve the gains in Overall Survival (OS) seen with current treatment protocols. With this in mind we undertook a study of outcomes of NSS performed in the USA using a large population-based registry.

METHODS

We retrospectively queried the SEER Research Plus 18-registries Database 2010-2018 for patients 18 years old or younger with Wilms tumor as determined by ICD-O-3 code 8960. Clinical and demographic data was extracted, and statistical analysis was performed in GraphPad PRISM 9 with bivariate analysis and log-rank analysis to determine survival.

RESULTS

1087 patients with Wilms tumor were identified. 73 (6.72%) underwent nephron-sparing surgery. The final cohort consisted of 45 patients (64%) who underwent unilateral NSS and 25 patients (36%) who underwent bilateral NSS. Three were excluded from analysis due to non-renal origin of tumor. Mean age was 3.214 years (std dev 3.807). Demographics were similar between the groups, apart from younger age associated with bilateral tumor (p = 0.0441). No differences were found between radiation use (p = 0.4280), chemotherapy use (p = 0.5479), tumor size (p = 0.2186), positive regional lymph nodes (p = 0.707). Log-rank analysis demonstrated that cancer-specific survival was not significantly different between unilateral and bilateral NSS or radical nephrectomy (p = 0.4539).

CONCLUSION

NSS may preserve renal function long-term, an important consideration in the pediatric population. Prospective study is necessary to select the appropriate patient subsets who may benefit from NSS in WT.

Factors Associated With Lymph Node Yield and Effects of Lymph Node Density on Survival of Patients With Pulmonary Sarcomatoid Carcinoma

OBJECTIVE

The objective of this study was to identify factors associated with lymph node yield (LNY) during surgeries for pulmonary sarcomatoid carcinoma (PSC) and to determine effects of lymph node density (LND) on the overall survival (OS) of patients with PSC.

MATERIALS AND METHODS

The SEER Research Plus database was searched for data on patients with PSC from 1988 to 2018. Poisson regression was used of all patients with PSC to identify relevant factors associated with LNY. Univariate and multivariate Cox regression analyses were adopted for lymph node (LN)-positive patients to evaluate the impact of LND on OS. The 5-year OS rates of patients with PSC were compared based on their LN status and LND.

RESULTS

There were 545 eligible patients in the study sample, 175 of which were LN-positive. These patients had significantly lower 5-year OS than those with no positive LNs ( P <0.001). Poisson regression analysis indicated relevant factors increasing LNY included higher diagnosis age, non-Hispanic American Indian or Alaska Native races, larger tumor, pleomorphic carcinoma histology, and more advanced disease stages. The Cox regression analysis indicated higher LND ( P =0.022) was probably associated with a worse prognosis for LN-positive patients. The group with LND ≥0.12 had a higher risk of death than the group with LND <0.12 ( P <0.001) among LN-positive patients with PSC.

CONCLUSIONS

Patients with PSC with high LND experienced worse outcomes than those with low LND. Further risk stratification of patients with PSC may help to improve survival benefits based on prognostic indicators of LND.

Nephroblastoma Treatment and Outcomes in a Low-Income Setting

PURPOSE

Nephroblastoma is a highly curable pediatric cancer that requires multidisciplinary care. Few reports have assessed long-term treatment outcomes in low-resource settings using a task-shifting model of care. We report outcomes of a large cohort and factors associated with survival.

METHODS

We performed a retrospective chart review of all patients with nephroblastoma presenting to the Butaro Cancer Center of Excellence in Rwanda between July 2012 and June 2018.

RESULTS

In total, 136 patients were identified and treated according to International Society of Pediatric Oncology guidelines for low-income settings. Median age at diagnosis was 39.7 months (interquartile range, 25.3-61.8 months); 56.6% were female. Sixty-one (44.9%) patients presented with stage I-III disease, 35 (25.7%) with stage IV disease, and 6 (4.4%) with stage V disease; the remainder were unstaged (n = 34; 25.0%). Most patients completed surgery (n = 97; 71.3%) and postoperative chemotherapy (n = 82; 60.2%); 17 patients received radiotherapy. With a median follow-up time of 18.1 months, 44.9% of patients were alive, 41.9% had died, 8.8% were lost to follow-up, and 4.4% were referred for palliative care or declined further care at the end of the study. Three-year overall survival was 57.5% (95% CI, 48.1 to 65.8) for the entire cohort, and 80.1% (95% CI, 66.8 to 88.5) and 44.0% (95% CI, 26.8 to 60.0) for stages I-III and IV-V, respectively.

CONCLUSION

We demonstrate that patients with nephroblastoma can be successfully treated in a low-resource setting. Survival remains lower than in high-income countries, in part due to early deaths, contributing to approximately 30% of patients not being medically able to receive surgical intervention. Next steps include the development of strategies that focus on earlier diagnosis, supportive care during the early phases of therapy, and efficient and timely transitions between specialties for multimodal care.

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.