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

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.

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.

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).

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.