Patterns of chemotherapy-induced toxicities and outcome in children and adolescents with metastatic rhabdomyosarcoma: A report from the Children's Oncology Group

BACKGROUND

We sought to determine whether adolescents with metastatic alveolar rhabdomyosarcoma (ARMS) or embryonal RMS (ERMS) had a different event-free survival (EFS) compared with younger patients, and to identify treatment-related factors (adverse events, AEs) that may be associated with differences in outcome.

METHODS

The prevalence of AEs in adolescents older than 13 years was compared with that in patients less than or equal to 13 years of age (Fisher exact test) in patients enrolled onto ARST0431. EFS by age and histology was compared by log-rank test.

RESULTS

Of 109 patients, 60 (55%) were older than 13 years; they were more likely to have nausea (17 vs. 4%, P = 0.06) and pain (20 vs. 6%, P = 0.05) compared with younger patients. Adolescents were less likely to complete therapy (63 vs. 76%) and more likely to have unplanned dose modifications outside of protocol guidelines (23 vs. 2.7%). The 3-year EFS was 26% (95% confidence interval [CI]: 15-38) for adolescents compared with 46% (95% CI: 32-60) for those less than or equal to 13 years (P = 0.011). Forty-two (59%) adolescents with ARMS had a 3-year EFS of 13% (95% CI: 2-23) compared with 30% (95% CI: 10-51) for those less than or equal to 13 years (P = 0.032). EFS was comparable between older and younger patients with ERMS (64 vs. 55%, P = 0.53).

CONCLUSIONS

Although there was a significant difference in EFS and protocol compliance by age, the differences in age-related toxicity are unlikely to account for this. Observed differences in pain and nausea by age could be real or be dependent on patient reporting of symptoms. Future studies in RMS should include patient-reported outcomes to better evaluate health-related quality of life.

45 Gy is not sufficient radiotherapy dose for Group III orbital embryonal rhabdomyosarcoma after less than complete response to 12 weeks of ARST0331 chemotherapy: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

BACKGROUND

Recent Children's Oncology Group (COG) trials tested the efficacy of reduced therapy in an effort to lessen late effects compared to the Intergroup Rhabdomyosarcoma Study (IRS) IV regimen with associated hematologic and hepatic toxicity, and infertility. Here, we analyze the efficacy of 45 Gray (Gy) local radiotherapy (RT) in patients with Group III orbital embryonal rhabdomyosarcoma (ERMS) enrolled on the COG low-risk study ARST0331.

PROCEDURE

Sixty-two patients with Group III orbital ERMS were treated on ARST0331 with four cycles of vincristine (VCR), dactinomycin (DACT), and cyclophosphamide (CPM; VAC, total cumulative CPM dose 4.8 g/m2 ) followed by four cycles of VCR and DACT over 22 weeks. Forty-five Gray of radiation was administered in 25 fractions beginning at week 13 of therapy.

RESULTS

Fifty-three patients were evaluable for this response analysis; seven had missing week 12 response evaluation data and two had progressive disease prior to starting RT. Median follow-up was 7.8 years. None of the 15 patients with radiographic complete response (CR) compared to 6 of the 38 patients with

CONCLUSIONS

For patients with Group III orbital ERMS achieving a CR following VAC chemotherapy that includes modest dose CPM, 45 Gy may be sufficient for durable failure-free survival. However, for those with Collapse

Key Words

• orbital rhabdomyosarcoma
• radiotherapy
• response based

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MESH Headings

• Antineoplastic Combined Chemotherapy Protocols/therapeutic use
• Child
• Child, Preschool
• Combined Modality Therapy
• Female
• History, Ancient
• Humans
• Kaplan-Meier Estimate
• Male
• Orbital Neoplasms/drug therapy
• Orbital Neoplasms/mortality
• Orbital Neoplasms/radiotherapy
• Radiation Dosage
• Radiotherapy/methods
• Rhabdomyosarcoma, Embryonal/drug therapy
• Rhabdomyosarcoma, Embryonal/mortality
• Rhabdomyosarcoma, Embryonal/radiotherapy

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Grants

• U10 CA098413 NCI NIH HHS
• U10 CA098543 NCI NIH HHS
• U10 CA180899 NCI NIH HHS

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Investigating the heterogeneity of alkylating agents' efficacy and toxicity between sexes: A systematic review and meta-analysis of randomized trials comparing cyclophosphamide and ifosfamide (MAIAGE study)

BACKGROUND

A marginal interaction between sex and the type of alkylating agent was observed for event-free survival in the Euro-EWING99-R1 randomized controlled trial (RCT) comparing cyclophosphamide and ifosfamide in Ewing sarcoma. To further evaluate this interaction, we performed an individual patient data meta-analysis of RCTs assessing cyclophosphamide versus ifosfamide in any type of cancer.

METHODS

A literature search produced two more eligible RCTs (EICESS92 and IRS-IV). The endpoints were progression-free survival (PFS, main endpoint) and overall survival (OS). The hazard ratios (HRs) of the treatment-by-sex interaction and their 95% confidence interval (95% CI) were assessed using stratified multivariable Cox models. Heterogeneity of the interaction across age categories and trials was explored. We also assessed this interaction for severe acute toxicity using logistic models.

RESULTS

The meta-analysis comprised 1,528 pediatric and young adult sarcoma patients from three RCTs: Euro-EWING99-R1 (n = 856), EICESS92 (n = 155), and IRS-IV (n = 517). There were 224 PFS events in Euro-EWING99-R1 and 200 in the validation set (EICESS92 + IRS-IV), and 171 and 154 deaths in each dataset, respectively. The estimated treatment-by-sex interaction for PFS in Euro-EWING99-R1 (HR = 1.73, 95% CI = 1.00-3.00) was not replicated in the validation set (HR = 0.97, 95% CI = 0.55-1.72), without heterogeneity across trials (P = 0.62). In the pooled analysis, the treatment-by-sex interaction was not significant (HR = 1.31, 95% CI = 0.89-1.95, P = 0.17), without heterogeneity across age categories (P = 0.88) and trials (P = 0.36). Similar results were observed for OS. No significant treatment-by-sex interaction was observed for leucopenia/neutropenia (P = 0.45), infection (P = 0.64), or renal toxicity (P = 0.20).

CONCLUSION

Our meta-analysis did not confirm the hypothesis of a treatment-by-sex interaction on efficacy or toxicity outcomes.

Abstract 1948: Tumor-specific copy number alterations uncover therapeutic opportunities in osteosarcoma

Osteosarcoma (OS) is a highly malignant cancer for which no targeted therapies are currently available. Current treatment modalities are limited to intensive, highly toxic chemotherapy and surgical resection. OS is characterized by wide spread copy number alterations and structural rearrangements. In contrast, no recurrent point mutations in protein-coding genes have been identified, suggesting that copy number alterations (CNAs) are key oncogenic drivers in this disease. However, as copy number alterations are highly heterogeneous, it is likely that each tumor has a distinct set of oncogenic drivers, making a unified treatment approach difficult to define. To identify candidate patient-specific drivers, we used a simple heuristic based on degree of amplification (as assessed by Whole Genome Sequencing) and changes in gene expression (as assessed by RNA sequencing). Using patient-derived tumor xenografts (PDTXs), we assessed if individual OS tumors respond to targeted therapy selected based on this approach. We rank-ordered CNAs in 9 PDTXs by the amplitude of the copy number gain and identified 5 pathways for targeted therapy including CCNE1, MYC, CDK4, PTEN/AKT and AURKB. Next, we prioritized drug choices to those that are in clinical trials and that are readily available and identified 5 drug matches for 9 PDTXs. We used the CDK2 inhibitor Dinaciclib for CCNE1 amplification and observed TGI of 85.5% and 67.8% for 2 different CCNE1 amplified PDTXs tested. CDK9 inhibitor AT7519 was used to treat 2 different MYC amplified PDTXs resulting in TGI of 104% and 83.9%. CDK4 amplified PDTXs were treated with CDK4/6 inhibitor, Palbociclib, resulting in TGI of 82.7%. AKT1 inhibitor MK-2206 was used to treat either AKT1 gains or PTEN loss resulting in TGI of 65.6% and 60.8% respectively. AURKB inhibitor AZD-1152 for AURKB amplified PDTXs in combination with cisplatin resulting in TGI 85.8%. These results support the hypothesis that specific genes within CNA regions serve as oncogenic drivers and that these represent therapeutic opportunities in OS. Our studies provide a roadmap for personalized genome-informed therapy of osteosarcoma, a cancer in which no new therapies have been identified in over 30 years.

Citation Format: Leanne C. Sayles, Marcus Breese, Amanda L. Koehne, Stanley Leung, Aviv Spillinger, Alex Lee, Avanthi Shah, Krystal Straessler, Sheri Spunt, Neyssa Marina, Damon Jacobson, Raffi S. Avedian, David G. Mohler, Steven DuBois, Douglas S. Hawkins, E. Alejandro Sweet-Cordero. Tumor-specific copy number alterations uncover therapeutic opportunities in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1948. doi:10.1158/1538-7445.AM2017-1948

The efficacy of larotrectinib (LOXO-101), a selective tropomyosin receptor kinase (TRK) inhibitor, in adult and pediatric TRK fusion cancers

LBA2501

Background: Larotrectinib is the first selective small-molecule pan-TRK inhibitor. TRK fusions appear oncogenic independent of tumor lineage, are widely distributed across cancers, and affect all ages. We present an integrated dataset from 3 studies intended to support regulatory approval. Methods: All NTRK fusion pts with RECIST measurable disease enrolled to the adult (NCT02122913, n=8) and pediatric (NCT02637687, n=12) phase I trials and adult/adolescent phase 2 trial (NCT02576431, n=35) were analyzed. TRK fusion status was determined by local testing prior to enrollment. Pts were dosed predominantly at 100mg BID on a continuous 28-day schedule. Primary objective was investigator-assessed overall response rate (ORR) per RECIST v1.1. Secondary endpoints included duration of response (DOR) and safety. Data were cut on 31-JAN-2017. Results: 55 TRK fusion pts (12 peds, 43 adult, range: 4 mo.-76 yrs) were enrolled (median priors=2). Fusions involved NTRK1 (n=25), NTRK2 (n=1), and NTRK3 (n=29), and 14 unique partners. 13 discrete tumor types were treated: salivary (12), sarcoma (10), infantile fibrosarcoma (7), lung (5), thyroid (5), colon (4), melanoma (4), cholangio (2), GIST (2), and other (4). For the 46 pts evaluated to date, the ORR was 78% (95% CI: 64%–89%) with responses in 12 unique tumor types. Responses are ongoing in 29/33 (88%) pts, excluding 3 peds pts whose DOR was censored at attempted curative resection. A median DOR has not been reached as the majority of responders remain on treatment without progression. The longest responder remains on treatment at 23 mos., 8 pts remain in response at >12 mos., and 16 pts at >6 mos. NTRK solvent front mutations were detected in all 4 pts to develop acquired resistance. The most common TEAEs were fatigue (30%), dizziness (28%), and nausea (28%). 5 (11%) pts required dose reductions. Conclusions: Larotrectinib has demonstrated consistent and durable antitumor activity in TRK fusion cancers, across a wide range of ages and tumor types, and was well-tolerated. Larotrectinib could be the first targeted therapy developed in a tissue type-agnostic manner, and the first developed simultaneously in adults and pediatrics. Clinical trial information: NCT02576431, NCT02122913, NCT02637687.

The efficacy of larotrectinib (LOXO-101), a selective tropomyosin receptor kinase (TRK) inhibitor, in adult and pediatric TRK fusion cancers

LBA2501

The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Saturday, June 3, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Saturday edition of ASCO Daily News.

A pediatric phase I study of larotrectinib, a highly selective inhibitor of the tropomyosin receptor kinase (TRK) family

10510

Background: Larotrectinib is the first selective small-molecule inhibitor of TRKA, B, and C in clinical development. Data from the adult phase I trial demonstrate prolonged responses in patients (pts) with TRK fusions and a favorable tolerability profile. Methods: This multicenter, rolling 6 phase I study enrolled pts with refractory solid or CNS tumors aged ≥ 1 month – 21 years. Pts were dosed orally BID on a continuous 28-day schedule either by capsule or solution. Pharmacokinetic (PK)-directed intra-subject dose escalation was permitted, with exposures targeting the adult recommended Phase II dose (RP2D) of 100 mg BID. The primary objective was to define the MTD / RP2D; secondary objectives included PK and efficacy using RECIST v1.1. Results: As of December 31, 2016, 17 pts (12 with TRK fusions, 5 without TRK fusions) with a median age of 5.2 years (0.4 – 18.3) were enrolled to 3 dose levels. Pts were enrolled with fusions of all 3 NTRK genes: NTRK1 (n=6), NTRK2 (n=1), and NTRK3 (n=5) in heterogeneous tumor diagnoses: infantile fibrosarcoma (IFS) (n=6), other sarcoma (n=4), and papillary thyroid cancer (n=2). Most common AEs regardless of attribution were vomiting, diarrhea, and fatigue. While 8 (47%) pts experienced grade 3-4 AEs, none were attributed to larotrectinib. No DLTs were observed and an MTD was not established. Both formulations delivered dose-dependent PK comparable to the adult RP2D at dose level 3. 12 pts (10 with TRK fusions, 2 without TRK fusions) remain on treatment with median follow-up of 2.8 months (0.7 – 8.4). Among TRK fusion pts, the vast majority have achieved confirmed RECIST responses regardless of tumor diagnoses. No responses were seen in pts without TRK fusions (n=4). 5 pts discontinued therapy, including 2 with TRK fusions: 1 pt with IFS had sufficient response to allow tumor resection, and 1 pt with IFS progressed with a documented acquired resistance mutation. Conclusions: Larotrectinib has demonstrated a favorable tolerability profile and histology-independent efficacy in pediatric pts harboring TRK fusions. Updated safety and efficacy data will be presented, including the RP2D, response rate, duration of response, and use of larotrectinib in the pre-surgical setting. Clinical trial information: NCT02637687.

Risk stratification including FOXO1 fusion status (FOXO1) in patients with rhabdomyosarcoma (RMS) treated on six recent frontline trials: A report from the Children's Oncology Group (COG)

10528

Background: Clinical risk factors associated with outcome in children with either localized or metastatic RMS were identified by Meza et al. (2006) and Oberlin et al. (2008). We re-examined risk stratification by adding FOXO1 to traditional clinical prognostic factors in children with localized or metastatic RMS in a large cohort from COG frontline clinical trials. Methods: Data from six COG clinical trials (D9602, D9802, D9803, ARST0331, ARTS0431, ARST0531) accruing previously untreated patients with RMS from 1997 to 2013 yielded 1,853 eligible patients (two studies each for low, intermediate and high risk patients). Survival tree regression for event-free survival (EFS) and overall survival (OS) was conducted to determine prognostic impact of risk factors. Recursively, the factor most strongly associated with outcome was selected for branching and split using a goodness of fit measure. Factors included were age, FOXO1, group, histology, nodal status, number of metastatic sites, primary site, sex, tumor size, and presence of metastases in bone/bone marrow, soft tissue, effusions, lung, distant lymph nodes, and other sites. Results: 5-year overall EFS and OS was 0.67 (SE, 0.01) and 0.77 (SE, 0.01), respectively. Survival trees for EFS and OS found localized versus metastatic at the first split and included FOXO1 as a significant risk factor. Conclusions: FOXO1 improves risk stratification of patients with localized RMS, although histology and pattern of metastases are more predictive for patients with metastatic RMS. Our findings support incorporation of FOXO1 in risk stratified clinical trials. [Table: see text]

Phase 1/2 study of the selective TRK inhibitor larotrectinib in pediatric patients with cancer

TPS10577

Background: Neurotrophin ligands and their receptors TRKA, TRKB, and TRKC (encoded by NTRK1, NTRK2, and NTRK3) are important for growth regulation, differentiation and survival of neurons. Translocations involving the NTRK1/2/3 kinase domain, mutations involving the TRK ligand-binding site, and amplifications of NTRK, have been described in diverse tumor types and may contribute to tumorigenesis. A broad range of pediatric malignancies have been found to harbor NTRK fusions, including infantile fibrosarcoma (IFS), spindle-cell sarcoma, congenital mesoblastic nephroma, pediatric papillary thyroid cancer, pediatric gliomas and Ph-like acute lymphoblastic leukemia. Larotrectinib is the first small-molecule selective inhibitor of TRKA, -B, and -C in clinical development and preliminary data from the adult phase 1 trial demonstrate prolonged responses in patients with TRK fusions and a favorable safety profile. Methods: We have initiated an open-label, multi-center, international Phase 1/2 study with larotrectinib in pediatric patients with solid tumors and primary CNS tumors (NCT02637687). Patients with advanced cancer between the ages of 1 year and 21 years are eligible, as well as patients as young as 1-month of age with a documented NTRK fusion. Patients with IFS who have not had definitive surgery are also eligible. Larotrectinib is administered orally twice daily on a continuous 28-day schedule. Dosing is based on body surface area. Larotrectinib is available in an oral liquid formulation and capsules. Following identification of the maximum tolerated dose of larotrectinib in the phase 1 portion, the phase 2 portion will commence. The phase 2 portion will enroll patients with NTRK-translocated tumors and measurable disease into three cohorts: 1) infantile fibrosarcoma; 2) extracranial solid tumors; and 3) primary CNS tumors. The primary endpoint for the phase 2 portion is objective response rate, with duration of response and progression free survival as secondary efficacy endpoints. Each phase 2 cohort will enroll in a single stage of up to 10 patients per cohort. Molecular abnormalities will be characterized through the analysis of archival tissue. Enrollment began in December 2015 and is ongoing. Clinical trial information: NCT02637687.

Clinical trial enrollment of adolescents and young adults with sarcoma

More than half of all sarcomas occur in adolescents and young adults (AYAs) aged 15 to 39 years. After the publication of the AYA series in the April 1, 2016 issue of Cancer, several leaders in the field of sarcoma across disciplines gathered to discuss the status of sarcoma clinical research in AYAs. They determined that a focused effort to include the underrepresented and understudied AYA population in current and future sarcoma clinical trials is overdue. Trial enrichment for AYA-aged sarcoma patients will produce more meaningful results that better represent the disease's biology, epidemiology, and treatment environment. To address the current deficit, this commentary outlines changes believed to be necessary to expediently achieve an increase in the enrollment of AYAs in sarcoma clinical trials. Cancer 2017;123:3434-40. © 2017 American Cancer Society.

Vaginal Ewing Sarcoma: An Uncommon Clinical Entity in Pediatric Patients

Ewing sarcoma, including classical Ewing sarcoma of the bone and primitive neuroectodermal tumors arising in bone or extraosseous primary sites, is a highly aggressive childhood neoplasm. We present two cases of Ewing sarcoma arising from the vagina in young girls. Previously reported cases in literature focused on their pathologic rather than radiographic features. We describe the spectrum of multimodality imaging appearances of Ewing sarcoma at this unusual primary site. Awareness of vaginal Ewing tumors may facilitate prompt diagnosis and lead to a different surgical approach than the more commonly encountered vaginal rhabdomyosarcoma.

Reduction of cyclophosphamide dose for patients with subset 2 low-risk rhabdomyosarcoma is associated with an increased risk of recurrence: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

BACKGROUND

Failure-free survival (FFS) and overall survival (OS) rates were found to improve on Intergroup Rhabdomyosarcoma Study (IRS) IV (IRS-IV) compared with IRS-III for patients with subset 2 (IRS stage 1, group III nonorbit or stage 3, group I/II) low-risk embryonal rhabdomyosarcoma with the addition of cyclophosphamide (total cumulative cyclophosphamide dose of 26.4 g/m² ) to the combination of vincristine and dactinomycin (VAC). The goal of Children's Oncology Group ARST0331 for subset 2 low-risk patients was to reduce the total cumulative cyclophosphamide dose without compromising FFS.

METHODS

Therapy included 4 cycles of VAC (total cumulative cyclophosphamide dose of 4.8 g/m² ) followed by 12 cycles of vincristine and dactinomycin over 46 weeks. Patients with group II or III tumors received radiotherapy, except for girls with group III vaginal tumors who enrolled before September 2009 and achieved a complete response with chemotherapy with or without delayed surgical resection.

RESULTS

Among 66 eligible patients who were followed for a median of 3.5 years, there were 20 failures versus 10.53 expected failures. The estimated 3-year FFS and OS rates were 70% (95% confidence interval [95% CI], 57%-80%) and 92% (95% CI, 83%-97%), respectively. The estimated 3-year FFS rate was 57% (95% CI, 33%-75%) for girls with subset 2 genital tract embryonal rhabdomyosarcoma (21 patients) and 77% (95% CI, 61%-87%) for all other subset 2 patients (45 patients) (P = .02).

CONCLUSIONS

The authors observed suboptimal FFS among patients with subset 2 low-risk rhabdomyosarcoma using reduced total cyclophosphamide. Eliminating radiotherapy for girls with group III vaginal tumors in combination with reduced total cyclophosphamide appeared to contribute to the suboptimal outcome. Cancer 2017;123:2368-2375. © 2017 American Cancer Society.

Non-invasive assessment of muscle oxygenation may aid in optimising transfusion threshold decisions in ambulatory paediatric patients

OBJECTIVE

To assess the potential utility of a novel non-invasive muscle oxygen measurement to determine the presence of muscle hypoxia in patients with anaemia.

BACKGROUND

Recent assessment of the risk/benefit ratio of blood transfusion has led to clinical strategies optimising transfusion decisions. These decisions are primarily based on haematocrit (Hct) but not oxygen delivery, the primary function of red blood cells (RBCs). We hypothesised that muscle oxygenation (MOx) would correlate with Hct in patients with anaemia and may be a physiologically relevant determinant of the transfusion threshold.

METHODS/MATERIALS

MOx was non-invasively determined in children in the Cancer and Blood Disorders Center ambulatory clinic at Seattle Children's Hospital using a custom-designed optical probe and spectrometer. MOx was compared with contemporaneous Hct. In subjects receiving RBCs, MOx and Hct were also determined following transfusion.

RESULTS

MOx ranged from 36·7 to 100%, and Hct ranged from 17·0 to 38·6% in 27 measurements from 16 patients. High MOx values were associated with high Hct. Mean MOx for patients with normal Hct for age (n = 5) was 95·9 ± 2·9%. RBC transfusion increased mean Hct from 19·1 ± 1·5% to 29·3 ± 2·0 and mean MOx from 67·9 ± 21·1% to 89·9 ± 9·8%. Among six transfusion episodes (in five patients) with initial Hct < 22, only three had a pre-transfusion MOx of <70%. Patients with the lowest pre-transfusion MOx had the largest increase in MOx after transfusion.

CONCLUSIONS

These preliminary data suggest that MOx may aid in making transfusion decisions when used in combination with Hct.

The Role of Childhood Infections and Immunizations on Childhood Rhabdomyosarcoma: A Report From the Children's Oncology Group

BACKGROUND

Rhabdomyosarcoma (RMS) is a rare, highly malignant tumor arising from primitive mesenchymal cells that differentiate into skeletal muscle. Relatively little is known about RMS susceptibility. Based on growing evidence regarding the role of early immunologic challenges on RMS development, we evaluated the role of infections and immunizations on this clinically significant pediatric malignancy.

PROCEDURE

RMS cases (n = 322) were enrolled from the third trial coordinated by the Intergroup Rhabdomyosarcoma Study Group. Population-based controls (n = 322) were pair matched to cases on race, sex, and age. The following immunizations were assessed: diphtheria, pertussis, and tetanus (DPT); measles, mumps, and rubella; and oral polio vaccine. We also evaluated if immunizations were complete versus incomplete. We examined selected infections including chickenpox, mumps, pneumonia, scarlet fever, rubella, rubeola, pertussis, mononucleosis, and lung infections. Conditional logistic regression models were used to calculate an odds ratio (OR) and 95% confidence interval (CI) for each exposure, adjusted for maternal education and total annual income.

RESULTS

Incomplete immunization schedules (OR = 5.30, 95% CI: 2.47-11.33) and incomplete DPT immunization (OR = 1.56, 95% CI: 1.06-2.29) were positively associated with childhood RMS. However, infections did not appear to be associated with childhood RMS.

CONCLUSIONS

This is the largest study of RMS to date demonstrating a possible protective effect of immunizations against the development of childhood RMS. Further studies are needed to validate our findings. Our findings add to the growing body of literature, suggesting a protective role of routine vaccinations in childhood cancer and specifically in childhood RMS.

Opportunities for Improvement in Pathology Reporting of Childhood Nonrhabdomyosarcoma Soft Tissue Sarcomas: A Report From Children's Oncology Group (COG) Study ARST0332

OBJECTIVES

Treatment of soft tissue tumors in young patients relies on the diagnostic information conveyed in the pathology report. We examined pathology reports from Children's Oncology Group ARST0332 for inclusion of data elements required in published guidelines.

METHODS

Pathology reports for 551 eligible patients were examined for required data elements defined by the College of American Pathologists, including tissue type, procedure, tumor site, tumor maximum diameter, macroscopic extent of tumor, histologic type, mitotic rate, extent of necrosis, tumor grade, margin status, use of ancillary studies, and pathologic stage.

RESULTS

Only 65 (12%) of 551 reports included all required data elements. Of reports containing synoptic templates, 57% were complete.

CONCLUSIONS

This study reveals significant opportunity to improve the quality of pathology reports in young patients with soft tissue tumors. Use of templates or checklists improves completeness of reports.

Factors Associated With Mortality in Pediatric vs Adult Nasopharyngeal Carcinoma

IMPORTANCE

Nasopharyngeal carcinoma (NPC) is endemic in some Asian regions but is uncommon in the United States. Little is known about the racial, demographic, and biological characteristics of the disease in pediatric patients.

OBJECTIVES

To improve understanding of the differences between pediatric and adult NPC and to determine whether race conferred a survival difference among pediatric patients with NPC.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all 17 317 patients with a primary diagnosis of NCP in the National Cancer Data Base from January 1, 1998, to December 31, 2011. Of these, 699 patients were 21 years or younger (pediatric); 16 618 patients, older than 21 years (adult). Data were analyzed after data collection.

EXPOSURE

Pediatric age at diagnosis of NPC.

MAIN OUTCOMES AND MEASURES

Demographic, tumor, and treatment characteristics of pediatric patients with NPC were compared with those of adults using the χ2 test for categorical variables. An adjusted Cox proportional hazards regression model was used to examine survival differences in pediatric patients relative to adult patients. In addition, the risk for pediatric mortality by race was estimated.

RESULTS

Of the 17 317 patients, a total of 699 pediatric and 16 618 adult patients were identified with a primary diagnosis of NPC (female, 239 pediatric patients [34.2%] and 5153 adult patients [32.4%]). Pediatric patients were most commonly black (299 of 686 [43.6%]), whereas adults were most likely to be non-Hispanic white (9839 of 16 504 [60.0%]; P < .001). Pediatric patients were less likely to be Asian (39 of 686 [5.7%]) than were adults (3226 of 16 405 [19.7%]; P < .001). Pediatric patients were more likely to have regional nodal evaluation and to present with stage IV disease (227 of 643 [35.3%] and 330 of 565 [58.4%], respectively) than were adult patients (3748 of 15 631 [24.0%] and 6553 of 13 721 [47.8%], respectively; P < .001 for both comparisons). Pediatric patients had a lower risk for mortality relative to adults (hazard ratio, 0.37; 95% CI, 0.25-0.56). No difference in mortality by racial group was found among pediatric patients (hazard ratio, 1.10; 95% CI, 0.82-1.40).

CONCLUSIONS AND RELEVANCE

Pediatric patients with NPC were more commonly black and presented more frequently with stage IV disease. Pediatric patients had a decreased mortality risk relative to adults, even after adjusting for covariables. Asian race was not associated with increased mortality in pediatric patients with NPC. Racial differences are not associated with an increased risk for mortality among pediatric patients.

Outcome of Patients With Recurrent Osteosarcoma Enrolled in Seven Phase II Trials Through Children's Cancer Group, Pediatric Oncology Group, and Children's Oncology Group: Learning From the Past to Move Forward

PURPOSE

The use of radiographic response as the primary end point in phase II osteosarcoma trials may limit optimal detection of treatment response because of the calcified tumor matrix. We performed this study to determine if time to progression could be used as an end point for subsequent studies.

PATIENTS AND METHODS

We performed a retrospective analysis of outcome for patients with recurrent/refractory osteosarcoma enrolled in one of seven phase II trials conducted by the Children's Oncology Group and predecessor groups from 1997 to 2007. All trials used RECIST or WHO radiographic response criteria and the primary end point of response rate. The following potential prognostic factors-age, trial, number of prior chemotherapy regimens, sex, and race/ethnicity-were evaluated for their impact on event-free survival (EFS). We used data from a phase II study (AOST0221) of patients with osteosarcoma who were given inhaled granulocyte-macrophage colony-stimulating factor with first pulmonary recurrence who had an EFS as well as biologic end point to determine the historical disease control rate for patients with fully resected disease.

RESULTS

In each included trial, the drugs tested were determined to be inactive on the basis of radiographic response rates. The EFS for 96 patients with osteosarcoma and measurable disease was 12% at 4 months (95% CI, 6% to 19%). There was no significant difference in EFS across trials according to number of prior treatment regimens or patient age, sex, and ethnicity. The 12-month EFS for the 42 evaluable patients enrolled in AOST0221 was 20% (95% CI, 10% to 34%).

CONCLUSION

The EFS was uniformly poor for children with recurrent/refractory osteosarcoma in these single-arm phase II trials. We have now constructed baseline EFS outcomes that can be used as a comparison for future phase II trials for recurrent osteosarcoma.

Current state of pediatric sarcoma biology and opportunities for future discovery: A report from the sarcoma translational research workshop

Sarcomas are a rare subgroup of pediatric cancers comprised of a variety of bone and soft-tissue tumors. While significant advances have been made in improving outcomes of patients with localized pediatric sarcomas since the addition of systemic chemotherapy to local control many decades ago, outcomes for patients with metastatic and relapsed sarcoma remain poor with few novel therapeutics identified to date. With the advent of new technologies to study cancer genomes, transcriptomes and epigenomes, our understanding of sarcoma biology has improved tremendously in a relatively short period of time. However, much remains to be accomplished in this arena especially with regard to translating all of this new knowledge to the bedside. To this end, a meeting was convened in Philadelphia, PA, on April 18, 2015 sponsored by the QuadW foundation, Children's Oncology Group and CureSearch for Children's Cancer that brought together sarcoma clinicians and scientists from North America to review the current state of pediatric sarcoma biology and ongoing/planned genomics based clinical trials in an effort to identify and bridge knowledge gaps that continue to exist at present. At the conclusion of the workshop, three key objectives that would significantly further our understanding of sarcoma were identified and a proposal was put forward to develop an all-encompassing pediatric sarcoma biology protocol that would address these specific needs. This review summarizes the proceedings of the workshop.

Histology, Fusion Status, and Outcome in Alveolar Rhabdomyosarcoma With Low-Risk Clinical Features: A Report From the Children's Oncology Group

BACKGROUND

Distinguishing alveolar rhabdomyosarcoma (ARMS) from embryonal rhabdomyosarcoma (ERMS) is of prognostic and therapeutic importance. Criteria for classifying these entities evolved significantly from 1995 to 2013. ARMS is associated with inferior outcome; therefore, patients with alveolar histology have generally been excluded from low-risk therapy. However, patients with ARMS and low-risk stage and group (Stage 1, Group I/II/orbit III; or Stage 2/3, Group I/II) were eligible for the Children's Oncology Group (COG) low-risk rhabdomyosarcoma (RMS) study D9602 from 1997 to 1999. The characteristics and outcomes of these patients have not been previously reported, and the histology of these cases has not been reviewed using current criteria.

PROCEDURE

We re-reviewed cases that were classified as ARMS on D9602 using current histologic criteria, determined PAX3/PAX7-FOXO1 fusion status, and compared these data with outcome for this unique group of patients.

RESULTS

Thirty-eight patients with ARMS were enrolled onto D9602. Only one-third of cases with slides available for re-review (11/33) remained classified as ARMS by current histologic criteria. Most cases were reclassified as ERMS (17/33, 51.5%). Cases that remained classified as ARMS were typically fusion-positive (8/11, 73%), therefore current classification results in a similar rate of fusion-positive ARMS for all clinical risk groups. In conjunction with data from COG intermediate-risk treatment protocol D9803, our data demonstrate excellent outcomes for fusion-negative ARMS with otherwise low-risk clinical features.

CONCLUSIONS

Patients with fusion-positive RMS with low-risk clinical features should be classified and treated as intermediate risk, while patients with fusion-negative ARMS could be appropriately treated with reduced intensity therapy.