The Evolving Role of Minimally Invasive Surgery in Pediatric and Adolescent Urologic Oncology

One year overall survival of wilms tumor cases and its predictors, among children diagnosed at a teaching hospital in South Western Uganda: a retrospective cohort study

BACKGROUND

Wilms tumor (WT) is the second most common solid tumor in Africa with both low overall survival (OS) and event-free survival (EFS) rates. However, no known factors are predicting this poor overall survival.

OBJECTIVE

The study was to determine the one-year overall survival of WT cases and its predictors among children diagnosed in the pediatric oncology and surgical units of Mbarara regional referral hospital (MRRH), western Uganda.

METHODOLOGY

Children's treatment charts and files diagnosed and managed for WT were retrospectively followed up for the period between January 2017 to January 2021. Charts of children with histologically confirmed diagnoses were reviewed for demographics, clinical and histological characteristics, as well as treatment modalities.

RESULTS

One-year overall survival was found to be 59.3% (95% CI: 40.7-73.3), with tumor size greater than 15 cm (p 0.021) and unfavorable WT type (p 0.012) being the predominant predictors.

CONCLUSION

Overall survival (OS) of WT at MRRH was found to be 59.3%, and predictive factors noted were unfavorable histology and tumor size greater than 115 cm.

Oncologic Fidelity of Minimally Invasive Surgery to Resect Neoadjuvant-Treated Wilms Tumors

Background

The Children's Oncology Group recommends upfront resection of Wilms tumor (WT), however, unique scenarios warrant neoadjuvant chemotherapy and delayed resection. We hypothesized that in the context of neoadjuvant chemotherapy, minimally invasive surgery (MIS) to resect WT achieves equivalent oncologic fidelity and better maintains therapy schedules.

Methods

A retrospective analysis of WT treated between 2010-2021 at a free-standing children's hospital was performed. Patient and disease specific characteristics were collected, and pre-resection tumor volumes (TV) were calculated. Impact of MIS or open resection on oncologic fidelity and time to resume chemotherapy was analyzed.

Results

For the study period, 62 patients were treated for 65 WT, and 14 patients (22.6%) received neoadjuvant chemotherapy to treat 17 WT (26.2%): 7 Stage I (all predisposition syndromes), 2 stage III, 7 stage IV, and 1 stage V (bilateral). MIS was utilized to resect 6 WT from 5 patients. For partial nephrectomy, pre-resection TV was 0.38 ml if MIS and 10.38 ml if open ( P = .025). For radical nephrectomy, pre-resection TV was 31.58 ml if MIS and 175.00 ml if open ( P = .101). No significant differences between surgical approach were detected regarding pathologic variables or survival. Epidural use was significantly greater with open procedures ( P = .001). Length of stay was 2.00 days after MIS compared to 6.00 for open resection ( P = .004). Time to resume chemotherapy was 7.00 days after MIS versus 27.00 for open ( P = .004).

Conclusion

After neoadjuvant chemotherapy for WT, MIS partial and radical nephrectomies achieved equivalent oncologic fidelity, reduced epidural use and post-operative stays, and better maintained adjuvant therapy timelines when compared to open resections.

Laparoscopic nephrectomy for Wilms' tumor: Can we expand on the current SIOP criteria?

INTRODUCTION

Wilms' tumor now has a good overall prognosis with open radical nephrectomy having been the mainstay of surgical treatment. Recently laparoscopic nephrectomy (LN) has been growing in popularity. The aim of our study was to review our indications and outcomes for laparoscopic resections for Wilms' tumor and compare indications with International Society of Paediatric Oncology (SIOP) criteria for LN.

MATERIAL AND METHODS

Patient demographics, preoperative management, surgical data, respect of SIOP criteria, complications, disease outcome, and follow-up were recorded on consecutive children who underwent nephrectomy for Wilms' tumor.

RESULTS AND DISCUSSION

Fifty-four consecutive children with Wilms' tumor underwent a nephrectomy; 20 had a LN (Table). Nine of 20 (45%) patients who had LN did not meet SIOP criteria for LN. No patients had an intraoperative tumor rupture and one patient had positive margins because of preoperative rupture. There were two conversions: one caused by difficulty accessing the renal hilum and the other caused by difficulty maintaining oxygen saturations. There was one local recurrence.

CONCLUSION

SIOP criteria are conservative and safe. Indications can be extended for teams experienced in surgical oncology and laparoscopy after agreement at a multidisciplinary meeting (MDM).

Open versus minimally invasive surgical approaches in pediatric urology: Trends in utilization and complications

OBJECTIVE

Minimally invasive surgery (MIS) techniques are anecdotally reported to be increasingly used, but little objective data supports this. Our objective was to assess trends in MIS utilization across various procedures in pediatric urology and to compare postoperative complication rates between MIS and open procedures.

METHODS

We analyzed the 1998-2012 Nationwide Inpatient Sample. We identified children (<18 years old) undergoing open and MIS inpatient procedures and any in-hospital post-operative complications that occurred during that postoperative hospitalization. We utilized propensity score matching and multivariable logistic regression to adjust for confounding factors.

RESULTS

We identified 163,838 weighted encounters in the "overall cohort," 70,273 of which were at centers performing more than five MIS procedures over the years studied. Use of MIS techniques increased significantly over time for several procedures, most prominently for nephrectomy (Fig.). The overall rate of complications was lower in patients undergoing MIS compared with open surgery (6% vs. 11%, p < 0.001). Specialized centers had a significantly lower overall rate of complications than unspecialized centers (9% vs. 12%, p < 0.001). Within specialized centers, MIS had lower complication rates than open procedures (7% vs. 9%, p < 0.001); this finding was consistent even after adjusting for other factors (OR 0.71, p = 0.02).

DISCUSSION

Limitations include that these data may not be generalizable to encounters not in the sample pool. As a large, retrospective, administrative database, NIS may be affected by miscoding bias - rendering our analysis sensitive to the accuracy of procedure coding in NIS. Although the accuracy level of NIS is high for an administrative database, it is possible at least some portion of our cohort may be incorrectly coded. Further, the NSQIP complications we identified may represent associated comorbidities and not true postoperative complications, as NIS does not provide temporal relationships between different diagnosis codes. Despite these limitations, we note that the NIS database is rigorously monitored and audited for coding accuracy and, therefore, represents a reasonably reliable panorama of the characteristics of an inpatient surgical cohort. However, it is important to note that the choice of operative modality is, undoubtedly, multifactorial and patient/setting-specific.

CONCLUSIONS

There is increasing use of MIS for pediatric urology procedures, although utilization rates vary among procedures. MIS was associated with a lower postoperative complication rate than for open procedures. Higher-volume MIS centers have a lower complication rate than lower-volume centers.

Recent advances in the management of Wilms' tumor

The objective of this article is to present an overview of recent trends in the management of Wilms’ tumor. With improved survival rates in the past few decades, critical long-term adverse therapy effects (such as renal insufficiency, secondary malignancies, and heart failure) and prevention measures (i.e. nephron-sparing surgery and minimizing the use of radiotherapy) have gained worldwide attention. Specific disease biomarkers that could help stratify high-risk from low-risk patients, and therefore fine-tune management, are in great demand. Ultimately, we aim to enhance clinical outcomes and maintain or improve current survival rates while avoiding undesirable treatment side effects and minimizing the exposure and intensity of chemotherapy and radiotherapy.