Prognostic impact of lymph node involvement and loss of heterozygosity of 1p or 16q in stage III favorable histology Wilms tumor: A report from Children’s Oncology Group Studies AREN03B2 and AREN0532

Abstract

IntroductionThe prognostic impact of positive lymph nodes (LN+) and/or singular loss of heterozygosity (LOH) of 1p or 16q were assessed in children with stage III favorable histology Wilms tumor (FHWT) enrolled on AREN0532 or AREN03B2 alone.Patients and MethodsA total of 635 stage III FHWT vincristine/dactinomycin/doxorubicin (DD4A)–treated patients met inclusion criteria. Event‐free survival (EFS) and overall survival are reported overall and by LN sampling, LN status, LOH 1p, LOH 16q, and a combination of LN status and singular LOH. Patients with unknown or positive combined LOH of 1p and 16q status and AREN03B2‐only patients with unknown outcomes or treatment other than DD4A were excluded.ResultsEFS did not differ by study, supporting pooling. Lack of LN sampling (hazard ratio [HR], 2.12; p = .0037), LN positivity (HR, 2.78; p = .0002), LOH 1p (HR, 2.18; p = .0067), and LOH 16q (HR, 1.72; p = .042) were associated with worse EFS. Compared with patients with both LN– and LOH–, those with negative nodes but positive LOH 1p or 16q and those with LN+ but LOH– for 1p or 16q had significantly worse EFS (HR, 3.05 and 3.57, respectively). Patients positive for both LN and LOH had the worst EFS (HR, 6.33; overall group factor, p < .0001).ConclusionFindings confirm LN+ status as an adverse prognostic factor amplified by presence of singular LOH 1p or 16q, supporting study of intensified therapy for patients with LN+ in combination with singular LOH in a prospective clinical trial.

Treatment of children with favorable histology Wilms tumor with extrapulmonary metastases: A report from the COG studies AREN0533 and AREN03B2 and NWTSG study NWTS‐5

“…Patients with combined LOH of 1p and 16q, previously shown to have prognostic importance in FHWT, 2,15 and those with 1q gain, associated with inferior outcomes in COG/NWTSG 4,16,17 and SIOP 18,19 cohorts, had inferior EFS that was not statistically significant. Patients with blastemal predominant histology at delayed nephrectomy, recently shown in COG analyses to have inferior outcomes, 13,20 similar to inferior outcomes in SIOP's blastemal-type patients, [21][22][23][24] had reduced EFS that did not reach significance. The sample size and limited percentage of patients with known biomarker status limits conclusions about these biologic variables.…”