The paradigm in nephroblastoma: neoadjuvant chemotherapy or primary nephrectomy? Single center experience, 20 years of follow up

Background: Nephroblastoma (Wilms tumor – WT) is the most common tumor of kidney in childhood. In the Czech Republic WT is treated according to SIOP protocols. The hallmark of these protocols is preoperative neoadjuvant chemotherapy (CHT), whereas nephrectomy is performed subsequently. In the present study we compare the survival of patients that underwent primary nephrectomy in comparison of patients treated with neoadjuvant CHT in a single center in more than 20 years period.

Patients and Methods: From 7/1988 to 5/2009 239 patients with WT were treated at Department of Pediatric Hematology and Oncology University Hospital Motol, Prague, Czech Republic. Event free survival (EFS) and overall survival (OS) was analyzed using Stat View statistical program.

Results: Patients we treated according to protocols: SIOP 9 (94 patients), SIOP 93 (80 patients) and SIOP 2001 (65 patients). Median follow-up is 12.5 years (3–21 years). 141 patients were classified as 1^st clinical stage, 16 2^nd stage, 29 3^rd stage, 34 4^th stage and 19 patients were 5^th stage. 120 patients from 239 (50%) were treated with neoadjuvant CHT, 119 patients (50%) underwent primary nephrectomy. The most common causes of primary nephrectomy were: rupture of tumor or supposed rupture of tumor (23x), massive hematuria and/or anemization (26x), uncertainty of diagnosis (21x) and others. EFS and OS patients treated with neoadjuvant CHT or primary nephrectomy do not differ (EFS 76.6% versus (vs.) 79.8%, p>0.05; OS 85.8% vs. 86.5%, p>0.05). 29 patients from 239 (12%) suffered from tumor spillage, EFS and OS do not differ again (EFS 76.6% vs. 78.8%, p>0.05; OS 83.3% vs. 86.5%, p>0.05). Preoperative tumor spillage was diagnosed in 21 cases (7x abdominal injury in anamnesis); all were treated with primary nephrectomy. Perioperative tumor spillage occurred in 8 cases, only 1 patient was treated with neoadjuvant CHT (1 from 120, 0.8%), 7 of them underwent primary nephrectomy (7 from 98, 7%, p=0.02). EFS of patients with spontaneous tumor spillage is 90% in comparison to 37% with perioperative tumor spillage, p=0.001. OS is 100% vs. 37% p<0.001, respectively.

Conclusions: We did not find any significant difference in EFS and OS in patients treated with neoadjuvant CHT or primary nephrectomy treated according to SIOP protocols at single institution. Patients suffering from perioperative tumor spillage have poor prognosis.

Supported by MH CZ – DRO, University Hospital Motol, Prague,Czech Republic 00064203.

No conflict of interest.

Keywords:
nephroblastoma
Treatment
pediatric oncology

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