Customized approach for upfront or delayed resection using radiological criteria in unilateral, nonmetastatic pediatric renal tumors: A prospective study

Abstract

Background The availability of robust, equivalent data regarding outcomes for upfront or delayed surgery for renal tumors in children leads to a dilemma in selecting the initial treatment. Imaging criteria associated with the probability of rupture or incomplete resection may provide a more objective assessment for customization for the timing of surgery. Procedure Eighty‐three children with unilateral, nonmetastatic renal tumors were enrolled between January 2012 and April 2018. Upfront nephrectomy was performed in the absence or delayed surgery (after a biopsy and chemotherapy) in the presence of one or more imaging‐based high‐risk features, including perinephric spread or adjacent organ infiltration, tumors crossing the midline, intravascular thrombus, and extensive adenopathy. Post hoc analysis for interobserver concordance for high‐risk imaging features was also performed. Results The upfront surgery group (19) had predominantly stage I or II diseases (89%) and the histological types were Wilms (13), non‐Wilms (5) renal tumor, and an inflammatory lesion. The delayed surgery group had 60% with stage I or II diseases and the histological types were Wilms (60) and non‐Wilms (4) tumor. In addition, high‐risk pathology was identified in nine patients. Overall, 27 patients with Wilms tumors required radiotherapy and anthracycline because of stage III disease, including one in the immediate surgery group. The event‐free and overall survival (OS) at a median follow‐up of 39 months for Wilms tumor are 88% (95% confidence interval [CI]: 78.5‐94.9%) and 89% (95% CI: 81.4‐96.6%), 85.1% (95% CI: 73.8‐93.4%) and 86.5% (95% CI: 77.4‐95.8%) for the delayed, and 100% event‐free survival as well as OS (P = .1) in the upfront surgery group. Conclusion A customized approach pivoted on image‐based high‐risk features facilitates identification of patients with early‐stage renal tumor when the timing of surgery is tailored. Moreover, non‐Wilms tumor and high‐risk pathology are also identified.

Wilms Tumor in India: A Systematic Review

“…29,30 Similar observations have been made on two Indian studies that noted no association between increased tumor rupture, needle tract seeding, or tendency to relapse with a baseline biopsy. 31,32 Two centers have employed FNA cytology 12,24 instead of biopsy for establishing diagnosis, which has a comparable sensitivity and specificity. 33 The preferred practice in approximately half of the included studies combined the treatment philosophies of both NWTSG/COG and SIOP.…”

Imaging Recommendations for Diagnosis, Staging, and Management of Pediatric Solid Tumors

“…2. 16 Biopsy is recommended before starting chemotherapy if upfront surgery is not possible. Radical nephroureterectomy and lymph node sampling is the surgical procedure of choice 17 Clearance of the thrombus, if present, is performed and either cavotomy or partial cavectomy may be required depending on the extent of tumor thrombus.…”

“…Except for stage 1 and 2 tumors with favorable histology, post-operative radiotherapy is indicated for primary tumor bed and metastatic disease. 16,19 Upfront surgery is contraindicated in bilateral renal disease and in cases with solitary or horseshoe kidney. 16,20 For patients with bilateral Wilm's tumors, neoadjuvant chemotherapy is initiated, followed by delayed surgery in the form of bilateral partial nephrectomy or total nephrectomy on the worse side and partial nephrectomy on the opposite side.…”

“…16,19 Upfront surgery is contraindicated in bilateral renal disease and in cases with solitary or horseshoe kidney. 16,20 For patients with bilateral Wilm's tumors, neoadjuvant chemotherapy is initiated, followed by delayed surgery in the form of bilateral partial nephrectomy or total nephrectomy on the worse side and partial nephrectomy on the opposite side. Patients with tumor spillage/rupture, or regional lymph node metastasis are upstaged to stage III, and should receive abdominal radiotherapy and appropriate chemotherapy.…”

“…Except for stage 1 and 2 tumors with favorable histology, post-operative radiotherapy is indicated for primary tumor bed and metastatic disease. 16 19…”