Vincristine Pharmacokinetics in Infants

Inclusion Criteria

• •Patients must be =\< 12 years of age at the time of study enrollment. Patients will be stratified into 4 age groups:
• •* 0 to 6 months
• •* 6 months and 1 day to 12 months
• •* 12 months and 1 day to 36 months
• •* 36 months and 1 day to 12 years with a BSA ≥ 0.6 m\^2
• •Newly diagnosed and relapsed cancer diagnosis that is being treated with vinCRIStine at the 1.5 mg/m\^2 dose level
• •Any disease status
• •Patients must have a Lansky performance status of 50 or higher
• •Patients must be receiving a treatment regimen that includes 1.5 mg/m\^2 vinCRIStine (maximum dose 2 mg)
• •Patients with a BSA \< 0.6 m\^2 must be dosed according to the Children's Oncology Group (COG) BSA-banded infant dosing table for the 1.5mg/m2 dose level for vinCRIStine
• •* Note: Patients can be studied after any dose of vinCRIStine
• •Patients who are NOT enrolled on a COG clinical trial and who have a BSA \< 0.6 m\^2 and who are being dosed according to another infant dosing method (e.g., the 30-Rule) can receive a dose of vinCRIStine from the infant dosing table for the pharmacokinetic study. These patients will NOT be part of the Dose Modification Assessment
• •Patients with a seizure disorder may be enrolled if on allowable anticonvulsants and well controlled as evidenced by no increase in seizure frequency in the prior 7 days
• •Nervous system toxicities (Common Terminology Criteria for Adverse Events \[CTCAE\]) version (v)5 resulting from prior therapy must be grade =\< 2
• •Central venous access device in place (e.g., percutaneous indwelling central catheter \[PICC\], port, Broviac) or scheduled to be placed prior to the dose of vinCRIStine and that can be used for pharmacokinetic (PK) sampling
• •VinCRIStine may be given as an outpatient, as long as all sample time points can be collected, which will require return for hour 24 sampling