Principles of pediatric surgical oncology

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What are the surgical guidelines for the treatment of neuroblastoma? How does stage affect operative management decisions?

Surgical goals include establishing a definitive diagnosis, accurate staging, and gross total resection, if possible. For stage I to II disease, upfront resection is encouraged with complete dissection of the primary tumor site, regional lymph nodes, and adjacent vasculature. En-bloc resection and/or injury to surrounding vital structures is discouraged. Surgical approach depends on tumor characteristics, location, and relation to surrounding structures. For extensive stage III to IV, initial surgery should be limited to biopsy of tumor tissue, staging, and placement of a vascular access device. After four to five cycles of chemotherapy, surgical resection is re-evaluated after repeat imaging is obtained.

2

What staging systems are used for neuroblastoma?

The International Neuroblastoma Staging System (INSS) evaluates tumor size and location relative to midline, the presence and extent of metastatic disease, and the extent of surgical resection of the primary tumor. The International Neuroblastoma Risk Group (INRG) is a classification system that determines pretreatment risk stratification based on age, image defined risk factors (IDRF), and histological and biological factors of the tumor.

3

Define the principles used for staging Wilms tumor.

Wilms tumor is assigned a local and disease stage. Local stage is determined clinicopathologically by the surgeon at the time of operation and confirmed by the pathologist. Intraoperative assessment for the presence and quality of peritoneal fluid and/or studding, assessment of the tumor capsule, and palpation of renal vein and vena cava provide essential information for staging.

4

Describe the surgical guidelines for the treatment of Wilms tumor.

Upfront resection of the tumor is the mainstay of surgical therapy, without preoperative biopsy. Complete unilateral radical nephroureterectomy with lymph node sampling and without tumor spillage or rupture is the main goal. Visualization and palpation of the contralateral kidney is not necessary, if imaging is normal. The extent of contamination by “spilled” tumor (e.g., limited spill after biopsy versus widespread after tumor rupture) is crucial to accurate staging because it determines adjuvant chemotherapy and the extent of radiation therapy directed at the abdomen (e.g., flank versus whole abdominal radiation).

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