A Study Comparing Higher Dose Chemotherapy Over a Shorter Amount of Time to Lower Dose Chemotherapy Plus Maintenance Over a Longer Amount of Time in Patients With Newly Diagnosed Intermediate-Risk Rhabdomyosarcoma (IR RMS)

PRIMARY OBJECTIVE: I. To determine if the event free survival (EFS) of patients with intermediate risk rhabdomyosarcoma (IR RMS) treated with surgery, radiotherapy, and vincristine, dactinomycin, cyclophosphamide (VAC) (2.2 g/m\^2/cycle cyclophosphamide) chemotherapy (regimen A) is better than that of patients treated with surgery, radiotherapy, and VAC alternating with vincristine, irinotecan (VI) (VAC/VI) (1.2 g/m\^2/cycle cyclophosphamide) chemotherapy plus 24 weeks of maintenance chemotherapy with vinorelbine and cyclophosphamide (regimen B). SECONDARY OBJECTIVES: I. To determine if the overall survival (OS) of patients with IR RMS treated with surgery and/or radiotherapy, and VAC (2.2 g/m\^2/cycle cyclophosphamide) chemotherapy (regimen A) is better than the OS of patients treated with surgery, radiotherapy, and VAC alternating with VI (VAC/VI) (1.2 g/m\^2/cycle cyclophosphamide) plus 24 weeks of maintenance chemotherapy with vinorelbine and cyclophosphamide (regimen B). II. To compare clinician-reported treatment-related adverse event (AE) rates between two regimens. III. To determine what proportion of patients deemed eligible for delayed primary excision (DPE) on retrospective central review undergo DPE and to assess the concordance of DPE eligibility between the central review and local site. IV. To compare the 4-year local failure (LF) rate of patients deemed DPE-eligible by retrospective central review who undergo DPE with the 4-year LF rate of patients deemed DPE-eligible by central review who do not undergo DPE. V. To determine the feasibility of reporting diagnostic tumor molecular features identified via the Molecular Characterization Initiative (MCI) within 6 weeks of treatment initiation for clinical group III patients. EXPLORATORY OBJECTIVES: I. To prospectively evaluate the following somatic molecular features (PAX3 or PAX7 and FOXO1 fusion, MYCN amplification, TP53 mutation, MYOD1 mutation, CDK4 amplification) via MCI and determine their association with EFS and OS. II. To explore the relationship between methylation patterns in IR RMS and EFS and OS. III. To test the use of digital pathology/artificial intelligence to refine the diagnosis of IR RMS. IV. To assess the differential impact of regimen intensity on gonadal toxicity experienced by patients. V. To determine the proportion of patients having fertility discussions and fertility preservation procedures prior to starting treatment. VI. To collect biospecimens for patient-derived xenograft (PDX) RMS model generation. VII. To bank biospecimens for future research. VIII. To evaluate the association between Household Material Hardship (HMH) measures and EFS and OS. OUTLINE: Patients are randomized to 1 of 2 regimens. REGIMEN A: CYCLES 1-4, 8, 12: Patients receive vincristine intravenously (IV) on days 1, 8 and 15 of each cycle, dactinomycin IV over 1-5 or 10-15 minutes on day 1 of each cycle, and cyclophosphamide IV over 1-6 hours on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. CYCLES 5, 9, 10, 13, 14: Patients receive vincristine IV on day 1 of each cycle, dactinomycin IV over 1-5 or 10-15 minutes on day 1 of each cycle, and cyclophosphamide IV over 1-6 hours on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. CYCLE 6: Patients receive vincristine IV on day 1 and cyclophosphamide IV over 1-6 hours on day 1. Cycle 6 continues for 21 days in the absence of disease progression or unacceptable toxicity. CYCLE 7: Patients receive vincristine IV on days 1, 8 and 15 and cyclophosphamide IV over 1-6 hours on day 1. Cycle 7 continues for 21 days in the absence of disease progression or unacceptable toxicity. Patients may undergo surgical resection during cycle 4 (week 12), radiation to the primary site during cycle 5 and 6 and/or radiation to distant metastatic sites during cycle 14. Patients do not receive dactinomycin during radiation. Patients undergo computed tomography (CT) scan and/or magnetic resonance imaging (MRI) and blood sample collection throughout the study. Patients may undergo lymph node biopsy during screening and/or fludeoxyglucose (FDG) positron emission tomography (PET) scan, bone scan, bone marrow biopsy and aspiration, lumbar puncture with cerebrospinal fluid sample collection throughout the study. REGIMEN B: CYCLES 1, 3, 8: Patients receive vincristine IV on days 1, 8 and 15 of each cycle, dactinomycin IV over 15 or 10-15 minutes on day 1 of each cycle, and cyclophosphamide IV over 1-6 hours on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. CYCLES 2, 4, 11: Patients receive vincristine IV on days 1, 8 and 15 of each cycle and irinotecan IV over 90 minutes on days 1-5 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. CYCLES 5, 10, 12, 14: Patients receive vincristine IV on day 1 of each cycle, dactinomycin IV over 15 or 10-15 minutes on day 1 of each cycle, and cyclophosphamide IV over 1-6 hours on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. CYCLES 6, 7, 9, 13: Patients receive vincristine IV on days 1 and 8 of each cycle and irinotecan IV over 90 minutes on days 1-5 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients may undergo surgical resection during cycle 4 (week 12), radiation to the primary site during cycle 5 and 6 and/or radiation to distant metastatic sites during cycle 14. Patients do not receive dactinomycin during radiation. MAINTENANCE: Patients receive vinorelbine IV over 6-10 minutes on days 1, 8 and 15 of each cycle and cyclophosphamide orally (PO) once daily (QD) on days 1-28 of each cycle. Cycles repeat every 28 days for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT scan and/or MRI and blood sample collection throughout the study. Patients may undergo lymph node biopsy during screening and/or FDG PET scan, bone scan, bone marrow biopsy and aspiration, lumbar puncture with cerebrospinal fluid sample collection throughout the study. After completion of study treatment, patients are followed up every 3 months for 1 year, every 4 months for years 2 and 3 then every 6 months for year 4 and 5.