Embryonal sarcoma of the liver in pediatric and young adult patients: A report from Children’s Oncology Group study ARST0332

Abstract

BackgroundEmbryonal sarcoma of the liver (ESL) is a rare mesenchymal tumor most common in childhood; the optimal treatment approach is uncertain. The clinical features and outcomes of patients with ESL enrolled in a Children’s Oncology Group (COG) clinical trial that evaluated a risk‐based strategy for treating soft tissue sarcomas in patients aged <30 years were evaluated.MethodsThis subset analysis included patients with ESL enrolled in COG study ARST0332. Central review of records, pathology, and imaging confirmed the diagnosis, presenting features, and surgery extent and complications. All patients received dose‐intensive ifosfamide/doxorubicin chemotherapy, with cycle timing dependent on surgery and radiotherapy. Tumor resection occurred before study entry or after four cycles of chemotherapy; radiotherapy for residual tumor was optional.ResultsThirty‐nine eligible/evaluable patients with ESL were analyzed. All tumors were >10 cm in diameter; four were metastatic. Tumor resection was performed upfront in 23 and delayed in 16. Positive surgical margins (n = 6) and intraoperative tumor rupture (n = 6) occurred only in upfront resections. Eight patients received radiotherapy. Estimated 5‐year event‐free and overall survival were 79% (95% confidence interval [CI], 65%–93%) and 95% (95% CI, 87%–100%), respectively. Positive margins increased the local recurrence risk. One of 13 patients with documented hemorrhagic ascites and/or tumor rupture developed extrahepatic intra‐abdominal tumor recurrence.ConclusionsThe treatment strategy used in ARST0332 achieved favorable outcomes for patients with ESL despite a substantial proportion having high‐risk disease features. Deferring tumor resection until after neoadjuvant chemotherapy may decrease the risk of intraoperative tumor rupture and improve the likelihood of adequate surgical margins.

Rare pediatric tumors benefit from large clinical trials: The story of undifferentiated embryonal sarcoma of the liver

“…However, they took a different approach toward chemotherapy. In this issue of Cancer, Spunt et al 1 report on 39 prospectively treated patients with UESL with ifosfamide-doxorubicin chemotherapy as used in their COG nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) clinical protocol.…”

“…1,2 included patients with UESL with local and metastatic disease, although the number of metastatic patients was low (four in each study). The patients with upfront resection (EpSSG Intergroup Rhabdomyosarcoma Study[IRS] groups I and II/COG group C) all received adjuvant chemotherapy, and patients who were considered unresectable (EpSSG IRS group III/COG group D) received neoadjuvant chemotherapy and delayed surgery.…”