Douglas S. Hawkins

[18F]Fluorodeoxyglucose Positron Emission Tomography Predicts Outcome for Ewing Sarcoma Family of Tumors

PURPOSE Response to neoadjuvant chemotherapy is a significant prognostic factor for the Ewing sarcoma family of tumors (ESFTs). [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is a noninvasive imaging modality that accurately predicts histopathologic response in several malignancies. To determine the prognostic value of FDG PET response for progression-free survival (PFS) in ESFTs, we reviewed the University of Washington Medical Center experience. PATIENTS AND METHODS Thirty-six patients with ESFTs were evaluated by FDG PET. All patients received neoadjuvant and adjuvant chemotherapy. FDG PET standard uptake values before (SUV1) and after (SUV2) chemotherapy were analyzed and correlated with chemotherapy response, as assessed by histopathology in surgically excised tumors. Thirty-four patients had both SUV1 and SUV2. RESULTS The mean SUV1, SUV2, and ratio of SUV2 to SUV1 (SUV2:1) were 7.9 (range, 2.3 to 32.8), 2.1 (range, 0 to 4.3), and 0.36 (range, 0.00 to 1.00), respectively. Good FDG PET response was defined as SUV2 less than 2.5 or SUV2:1 < or = 0.5. FDG PET response by SUV2 or SUV2:1 was concordant with histologic response in 68% and 69% of patients, respectively. SUV2 was associated with outcome (4-year PFS 72% for SUV2 < 2.5 v 27% for SUV2 > or = 2.5, P = .01 for all patients; 80% for SUV2 < 2.5 v 33% for SUV2 > or = 2.5, P = .036 for localized at diagnosis patients). SUV2:1 < or = 0.5 was not predictive of PFS. CONCLUSION FDG PET imaging of ESFTs correlates with histologic response to neoadjuvant chemotherapy. SUV2 less than 2.5 is predictive of PFS independent of initial disease stage.

Comprehensive Genomic Analysis of Rhabdomyosarcoma Reveals a Landscape of Alterations Affecting a Common Genetic Axis in Fusion-Positive and Fusion-Negative Tumors

UNLABELLED Despite gains in survival, outcomes for patients with metastatic or recurrent rhabdomyosarcoma remain dismal. In a collaboration between the National Cancer Institute, Childrens Oncology Group, and Broad Institute, we performed whole-genome, whole-exome, and transcriptome sequencing to characterize the landscape of somatic alterations in 147 tumor/normal pairs. Two genotypes are evident in rhabdomyosarcoma tumors: those characterized by the PAX3 or PAX7 fusion and those that lack these fusions but harbor mutations in key signaling pathways. The overall burden of somatic mutations in rhabdomyosarcoma is relatively low, especially in tumors that harbor a PAX3/7 gene fusion. In addition to previously reported mutations in NRAS, KRAS, HRAS, FGFR4, PIK3CA, and CTNNB1, we found novel recurrent mutations in FBXW7 and BCOR, providing potential new avenues for therapeutic intervention. Furthermore, alteration of the receptor tyrosine kinase/RAS/PIK3CA axis affects 93% of cases, providing a framework for genomics-directed therapies that might improve outcomes for patients with rhabdomyosarcoma. SIGNIFICANCE This is the most comprehensive genomic analysis of rhabdomyosarcoma to date. Despite a relatively low mutation rate, multiple genes were recurrently altered, including NRAS, KRAS, HRAS, FGFR4, PIK3CA, CTNNB1, FBXW7, and BCOR. In addition, a majority of rhabdomyosarcoma tumors alter the receptor tyrosine kinase/RAS/PIK3CA axis, providing an opportunity for genomics-guided intervention.

Vincristine, Actinomycin, and Cyclophosphamide Compared With Vincristine, Actinomycin, and Cyclophosphamide Alternating With Vincristine, Topotecan, and Cyclophosphamide for Intermediate-Risk Rhabdomyosarcoma: Children's Oncology Group Study D9803

PURPOSE The purpose of this study was to compare the outcome of patients with intermediate-risk rhabdomyosarcoma (RMS) treated with standard VAC (vincristine, dactinomycin, and cyclophosphamide) chemotherapy to that of patients treated with VAC alternating with vincristine, topotecan, and cyclophosphamide (VAC/VTC). PATIENTS AND METHODS Patients were randomly assigned to 39 weeks of VAC versus VAC/VTC; local therapy began after week 12. Patients with parameningeal RMS with intracranial extension (PME) were treated with VAC and immediate x-ray therapy. The primary study end point was failure-free survival (FFS). The study was designed with 80% power (5% two-sided alpha level) to detect an increase in 5-year FFS from 64% to 75% with VAC/VTC. RESULTS A total of 617 eligible patients were entered onto the study: 264 were randomly assigned to VAC and 252 to VAC/VTC; 101 PME patients were nonrandomly treated with VAC. Treatment strata were embryonal RMS, stage 2/3, group III (33%); embryonal RMS, group IV, less than age 10 years (7%); alveolar RMS or undifferentiated sarcoma (UDS), stage 1 or group I (17%); alveolar RMS/UDS (27%); and PME (16%). At a median follow-up of 4.3 years, 4-year FFS was 73% with VAC and 68% with VAC/VTC (P = .3). There was no difference in effect of VAC versus VAC/VTC across risk groups. The frequency of second malignancies was similar between the two treatment groups. CONCLUSION For intermediate-risk RMS, VAC/VTC does not significantly improve FFS compared with VAC.

Rhabdomyosarcoma: Review of the Children's Oncology Group (COG) soft‐tissue Sarcoma committee experience and rationale for current COG studies

The prognosis for children and adolescents with rhabdomyosarcoma (RMS) has improved with refinements in multi‐modal therapy. Since 1972, the Intergroup Rhabdomyosarcoma Study Group (now the Childrens Oncology Group Soft‐Tissue Sarcoma Committee) has conducted serial studies for RMS. This review describes the IRSG and COG experience with RMS, presents the current risk stratification definitions, and provides rationale for the current generation of COG RMS studies. Pediatr Blood Cancer 2012; 59: 5–10.

Survival After Recurrence of Ewing’s Sarcoma Family of Tumors

PURPOSE The overall survival (OS) of patients with relapsed Ewings sarcoma family of tumors (ESFT) is poor, and the relative benefit of high-dose therapy (HDT) is controversial. PATIENTS AND METHODS We retrospectively identified 55 consecutive ESFT patients with adequate medical records for review, who were treated at Childrens Hospital and Regional Medical Center and who developed disease recurrence between January 1, 1985 and December 31, 2002. RESULTS The median relapse-free interval (RFI) from diagnosis to first recurrence was 17 months (range, 5 to 90 months). Most recurrences were metastatic only (39 patients) or local and metastatic (10 patients). Twenty-seven patients (49%) achieved a partial or complete response to second-line treatment, with a median duration of response of 27 months (range, 5 to 119+ months). The 5-year OS rate for all relapsed patients was 23% (95% CI, 11% to 35%). By univariate analysis, improved OS was associated with response to second-line treatment versus no response (46% v 0%, respectively; P < .0001), RFI > or = 24 months versus less than 24 months (48% v 12%, respectively; P = .0001), and no metastases at initial diagnosis versus presence of metastases (31% v 12%, respectively; P = .05). Because all 13 patients who received HDT also had responsive relapse, we performed a multivariate analysis. Reduced risk of death was associated with response to second-line therapy (relative risk, 0.14; 95% CI, 0.05 to 0.40), RFI > or = 24 months (relative risk, 0.29; 95% CI, 0.13 to 0.66), and receiving HDT (relative risk, 0.26; 95% CI, 0.08 to 0.85). CONCLUSION HDT as consolidation therapy for relapsed ESFT seems to be associated with improved OS, even after adjusting for RFI and response to second-line treatment.

Targeting Oxidative Stress in Embryonal Rhabdomyosarcoma

Rhabdomyosarcoma is a soft-tissue sarcoma with molecular and cellular features of developing skeletal muscle. Rhabdomyosarcoma has two major histologic subtypes, embryonal and alveolar, each with distinct clinical, molecular, and genetic features. Genomic analysis shows that embryonal tumors have more structural and copy number variations than alveolar tumors. Mutations in the RAS/NF1 pathway are significantly associated with intermediate- and high-risk embryonal rhabdomyosarcomas (ERMS). In contrast, alveolar rhabdomyosarcomas (ARMS) have fewer genetic lesions overall and no known recurrently mutated cancer consensus genes. To identify therapeutics for ERMS, we developed and characterized orthotopic xenografts of tumors that were sequenced in our study. High-throughput screening of primary cultures derived from those xenografts identified oxidative stress as a pathway of therapeutic relevance for ERMS.

Ewing Sarcoma: Current Management and Future Approaches Through Collaboration

Ewing sarcoma (ES) is an aggressive sarcoma of bone and soft tissue occurring at any age with a peak incidence in adolescents and young adults. The treatment of ES relies on a multidisciplinary approach, coupling risk-adapted intensive neoadjuvant and adjuvant chemotherapies with surgery and/or radiotherapy for control of the primary site and possible metastatic disease. The optimization of ES multimodality therapeutic strategies has resulted from the efforts of several national and international groups in Europe and North America and from cooperation between pediatric and medical oncologists. Successive first-line trials addressed the efficacy of various cyclic combinations of drugs incorporating doxorubicin, vincristine, cyclophosphamide, ifosfamide, etoposide, and dactinomycin and identified prognostic factors now used to tailor therapies. The role of high-dose chemotherapy is still debated. Current 5-year overall survival for patients with localized disease is 65% to 75%. Patients with metastases have a 5-year overall survival < 30%, except for those with isolated pulmonary metastasis (approximately 50%). Patients with recurrence have a dismal prognosis. The many insights into the biology of the EWS-FLI1 protein in the initiation and progression of ES remain to be translated into novel therapeutic strategies. Current options and future approaches will be discussed.

[F-18]-fluorodeoxy-D-glucose–positron emission tomography response is associated with outcome for extremity osteosarcoma in children and young adults

Response to neoadjuvant chemotherapy is 1 of the most powerful prognostic factors for extremity osteosarcoma. [F‐18]‐fluorodeoxy‐D‐glucose–positron emission tomography (FDG‐PET) is a noninvasive imaging modality that is used to predict histopathologic response. To determine the prognostic value of FDG‐PET response for progression‐free survival (PFS) in osteosarcoma, the authors of this report reviewed the University of Washington Medical Center experience.

PAX-FOXO1 fusion status drives unfavorable outcome for children with rhabdomyosarcoma: a children's oncology group report.

Rhabdomyosarcoma (RMS) is divided into two major histological subtypes: alveolar (ARMS) and embryonal (ERMS), with most ARMS expressing one of two oncogenic genes fusing PAX3 or PAX7 with FOXO1 (P3F and P7F, respectively). The Childrens Oncology Group (COG) carried out a multi‐institutional clinical trial to evaluate the prognostic value of PAX‐FOXO1 fusion status.

Asparaginase pharmacokinetics after intensive polyethylene glycol-conjugated L-asparaginase therapy for children with relapsed acute lymphoblastic leukemia.

Purpose: Asparaginase therapy is an important component in the treatment of children with acute lymphoblastic leukemia. Polyethylene glycol-conjugated asparaginase (PEG-ASNase) has significant pharmacological advantages over native Escherichia coli asparaginase. We investigated the pharmacokinetics of PEG-ASNase, presence of antibodies to PEG-ASNase, and concentrations of asparagine in serum and cerebrospinal fluid (CSF) in combination chemotherapy for relapsed pediatric acute lymphoblastic leukemia. Experimental Design: Twenty-eight pediatric patients with relapsed medullary (n = 16) and extramedullary (n = 11) acute lymphoblastic leukemia were enrolled at three pediatric institutions and had at least two serum and CSF samples obtained for analysis. Patients received induction therapy (including PEG-ASNase 2500 IU/m2 intramuscularly weekly on days 2, 9, 16, and 23) and intensification therapy (including PEG-ASNase 2500 IU/m2 intramuscularly once on day 7). Serum samples were obtained weekly during induction and intensification. CSF samples were obtained during therapeutic lumbar punctures during induction and intensification. Results: Weekly PEG-ASNase therapy resulted in PEG-ASNase activity of >0.1 IU/ml in 91–100% of patients throughout induction. During intensification, PEG-ASNase on day 7 resulted in PEG-ASNase activity >0.1 IU/ml in 94% and 80% of patients on days 14 and 21, respectively. Serum and CSF asparagine depletion was observed and maintained during induction and intensification in the majority of samples. PEG-ASNase antibody was observed in only 3 patients. Conclusions: Intensive PEG-ASNase therapy in the treatment of relapsed acute lymphoblastic leukemia reliably results in high-level serum PEG-ASNase activity, and asparagine depletion in serum and CSF is usually achieved. Incorporation of intensive PEG-ASNase in future trials for recurrent acute lymphoblastic leukemia is warranted.