Million, Lynn

AbstractBackgroundEmbryonal 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.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. ARST1321 was a phase II study designed to compare the near complete pathologic response rate after preoperative chemoradiation with/without pazopanib in children and adults with intermediate-/high-risk chemotherapy-sensitive body wall/extremity non-Rhabdomyosarcoma Soft Tissue Sarcoma (ClinicalTrials.gov identifier: NCT02180867 ). Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary aim of the study, the outcome data for this cohort were analyzed. Eight-five eligible patients were randomly assigned to receive (regimen A) or not receive (regimen B) pazopanib in combination with ifosfamide and doxorubicin + preoperative radiotherapy followed by primary resection at week 13 and then further chemotherapy at week 25. As of December 31, 2021, at a median survivor follow-up of 3.3 years (range, 0.1-5.8 years), the 3-year event-free survival for all patients in the intent-to-treat analysis was 52.5% (95% CI, 34.8 to 70.2) for regimen A and 50.6% (95% CI, 32 to 69.2) for regimen B ( P = .8677, log-rank test); the 3-year overall survival was 75.7% (95% CI, 59.7 to 91.7) for regimen A and 65.4% (95% CI, 48.1 to 82.7) for regimen B ( P = .1919, log-rank test). Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib, outcomes were not statistically significantly different between the two regimens.

AbstractBackground and ObjectivesThe impact upon wound healing of targeted molecular therapies, when incorporated into neoadjuvant therapy of soft tissue sarcoma, is largely unknown. Here, we describe wound complications following addition of pazopanib, a tyrosine kinase inhibitor (TKI), to neoadjuvant radiotherapy (RT) +/− chemotherapy for soft tissue sarcoma.MethodsWound complications were evaluated on dose‐finding and randomized arms of ARST1321, a phase II/III study incorporating neoadjuvant RT, +/− pazopanib, +/− ifosfamide/doxorubicin (ID) for sarcoma therapy.ResultsOf 85 evaluable patients, 35 (41%) experienced postoperative wound complications. Most (57%) were grade III. Randomization to pazopanib + RT + ID carried a 50% wound complication rate (17/34, with 47% grade III), compared to 22% (5/23) with ID + RT alone. In nonchemotherapy study arms, pazopanib + RT resulted in a 59% wound complication rate versus 25% for those receiving RT alone. Grade III wound complications occurred among 26% (15/58) of all patients receiving pazopanib. Wound complications occurred a median of 35 days postoperatively. Some occurred following diagnostic biopsies and at remote surgical sites.ConclusionThe addition of pazopanib to neoadjuvant chemotherapy and RT resulted in a higher wound complication rate following therapy of soft tissue sarcoma. The rate of grade III complications remained comparable to that reported in contemporary literature.

11504 Background: Pazopanib is a multi-targeted tyrosine kinase inhibitor (TKI) with activity in advanced soft tissue sarcoma. ARST1321 was a phase II study designed to compare the near complete pathologic response rate (≥ 90% necrosis) following preoperative chemoradiation +/- pazopanib in children and adults with intermediate/high risk chemotherapy-sensitive body wall/extremity NRSTS. Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary analysis of the study, we now report the outcome data for this cohort. Methods: ARST1321 was a jointly designed COG and NRG Oncology study open to enrollment July 2014-October 2018. Eligible adult (≥18 years) and pediatric (< 18 years) patients with newly-diagnosed unresected body wall/extremity NRSTS were enrolled into the Chemotherapy Cohort (> 5 cm, FNCLCC grade 2/3, protocol-designated chemotherapy-sensitive histology). Following a dose-finding phase, patients were randomized to receive (Regimen A) or not receive (Regimen B) pazopanib (< 18 years: 350 mg/m2/day; ≥ 18 years: 600 mg/day) in combination with ifosfamide (7.5 gm/m2/cycle) and doxorubicin (75 mg/m2/cycle) + 45 Gy preoperative RT followed by primary resection at week 13, then further chemotherapy to week 25. Results: Eighty-five eligible patients were enrolled in the Chemotherapy Cohort and randomized to receive or not receive pazopanib. Median age 22.1 years (range: 5.7-64.2 years); 30 patients < 18 years. Most common histologies were synovial sarcoma (n = 42) and undifferentiated pleomorphic sarcoma (n = 19). As of December 31, 2021, at a median survivor follow-up of 3.3 years (range: 0.1 – 5.8 years), the 3-year event-free survival (EFS) for all patients in the intent-to-treat analysis was 52.5% (95% CI: 34.8%-70.2%) for Regimen A and 50.6% (32%-69.2%) for Regimen B (p = 0.8677); 3-year overall survival (OS) was 75.7% (59.7%-91.7%) for Regimen A and 65.4% (48.1%-82.7%) for Regimen B (p = 0.1919). Conclusions: Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib to preoperative chemoradiation in children and adults with intermediate/high risk body wall/extremity NRSTS, outcomes were not statistically significantly different between the two regimens. Pathologic response could be a TKI-related phenomenon and may not be a good surrogate marker of outcome in future studies. Clinical trial information: NCT02180867.

11002 Background: Pazopanib is a multi-targeted tyrosine kinase inhibitor with activity in advanced soft tissue sarcoma. ARST1321 is a phase II study designed to compare the near complete pathologic response rate (≥ 90% necrosis) of preoperative chemoradiation +/- pazopanib in children and adults with intermediate/high risk chemotherapy-sensitive NRSTS. Methods: ARST1321 is a jointly designed COG and NRG Oncology study opened to enrollment in July 2014. Eligible adult (≥18 years) and pediatric ( < 18 years) patients with unresected, newly diagnosed truncal/extremity NRSTS were enrolled into the Chemotherapy Cohort ( > 5 cm, grade 2/3, protocol-designated chemotherapy-sensitive histology). Following a dose-finding phase, patients were randomized to receive (Regimen A) or not receive (Regimen B) pazopanib ( < 18 years: 350 mg/m2/day; ≥ 18 years: 600 mg/day) in combination with ifosfamide (7.5 gm/m2/cycle) and doxorubicin (75 mg/m2/cycle) + 45 Gy preoperative RT followed by primary resection at week 13, then adjuvant chemotherapy. Results: As of June 30, 2018, 81 eligible patients were enrolled and randomized. Week 13 response is available for 42 patients (60% of expected information). The rate of ≥ 90% pathologic necrosis was 58.3% for Regimen A and 22.2% for Regimen B. Based on the significance level of 0.081 (for the second efficacy analysis with overall one-sided significance level of 0.20, power of 0.80, and O’Brien-Fleming-type cumulative error spending function), the 83.8% confidence interval for the difference was between 16.5% and 55.8%. At this predetermined interim analysis, the efficacy bound was crossed indicating that Regimen A is more efficacious than Regimen B. Given these findings, enrollment was stopped. Grade 3/4 toxicities were 73.8% for Regimen A and 29% for Regimen B with neutropenia, thrombocytopenia and febrile neutropenia being the most common toxicities. Conclusions: The rate of near complete pathologic response was significantly greater with the addition of pazopanib to preoperative chemoradiation in children and adults with intermediate/high risk NRSTS. The comparison of survival outcomes requires longer follow-up. Clinical trial information: NCT02180867.

Purpose Intermediate-risk rhabdomyosarcoma (RMS) includes patients with either nonmetastatic, unresected embryonal RMS (ERMS) with an unfavorable primary site or nonmetastatic alveolar RMS (ARMS). The primary aim of this study was to improve the outcome of patients with intermediate-risk RMS by substituting vincristine and irinotecan (VI) for half of vincristine, dactinomycin, and cyclophosphamide (VAC) courses. All patients received a lower dose of cyclophosphamide and earlier radiation therapy than in previous trials. Patients and Methods Patients were randomly assigned at study entry to either VAC (cumulative cyclophosphamide dose, 16.8 g/m 2 ) or VAC/VI (cumulative cyclophosphamide dose, 8.4 g/m 2 ) for 42 weeks of therapy. Radiation therapy started at week 4, with individualized local control plans permitted for patients younger than 24 months. The primary study end point was event-free survival (EFS). The study design had an 80% power (5% one-sided α-level) to detect an improved long-term EFS from 65% (with VAC) to 76% (with VAC/VI). Results A total of 448 eligible patients were enrolled in the study. At a median follow-up of 4.8 years, the 4-year EFS was 63% with VAC and 59% with VAC/VI ( P = .51), and 4-year overall survival was 73% for VAC and 72% for VAC/VI ( P = .80). Within the ARMS and ERMS subgroups, no difference in outcome by treatment arm was found. Severe hematologic toxicity was less common with VAC/VI therapy. Conclusion The addition of VI to VAC did not improve EFS or OS for patients with intermediate-risk RMS. VAC/VI had less hematologic toxicity and a lower cumulative cyclophosphamide dose, making VAC/VI an alternative standard therapy for intermediate-risk RMS.

Purpose The goal of this study was to determine the frequency and clinical features of early treatment failure during induction chemotherapy before protocol radiation therapy for children with intermediate-risk rhabdomyosarcoma (RMS). Patients and Methods Patients with intermediate-risk RMS enrolled onto the Intergroup Rhabdomyosarcoma Study-IV and the Children's Oncology Group D9803 study were reviewed for an early treatment failure. Early failure was defined as failure caused by progressive disease, death as a result of progressive disease, or death as a result of other causes occurring fewer than 120 days from study entry. Patients with parameningeal site RMS with high-risk features who received radiation therapy at week 1 were excluded from analysis. Overall survival (OS) was estimated using the Kaplan-Meier method. Fisher's exact test was used to compare differences between groups. Cumulative incidence of progression was estimated. Results Of 916 patients, 20 (2.2%) were found to have an early disease progression and did not receive planned protocol radiotherapy. Three additional early failures resulted from treatment-related death without progression. Median time to failure was 48 days (range, 7 to 106 days). Nineteen (95%) of the 20 patients experienced progression at their primary site. Five-year OS was 32% (95% CI, 12% to 54%) for patients experiencing an early progression. Conclusion A small proportion of patients with intermediate-risk RMS suffer an early failure as a result of early progression (2.2%) or treatment-related mortality (0.3%). The majority of patients with early progression had a local failure. Earlier radiotherapy could potentially improve outcome by preventing early local progression.