RATIONALE: Studying samples of blood from patients with cancer in the laboratory may help doctors plan better treatment for patients receiving isotretinoin.

PURPOSE: This clinical trial is studying the side effects and best dose of isotretinoin in treating young patients with high-risk neuroblastoma.

OBJECTIVES:

Primary

• To investigate the feasibility of implementing individualized dosing of isotretinoin in patients with high-risk neuroblastoma after course 1 of treatment, based on isotretinoin pharmacokinetics and toxicity.
• To minimize the large inter-patient variation in plasma concentrations of isotretinoin.
• To ensure that patients are not exposed to potentially sub-optimal plasma concentrations of isotretinoin during long-term treatment, particularly for patients who are not able to swallow isotretinoin capsules.

Secondary

• To obtain preliminary data on the potential impact of isotretinoin therapeutic monitoring on clinical response and toxicity in these patients.

OUTLINE: This is a multicenter study.

Patients receive oral isotretinoin twice daily on days 1-14. Courses repeat every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity.

Blood samples are collected at baseline and during courses 1-3 for pharmacokinetic studies and determination of each patient's individual therapeutic-dose level requirement. Genotyping to identify genes that metabolize enzymes is conducted via PCR.

After completion of study therapy, patients are followed up periodically for up to 3 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed high-risk neuroblastoma
• Concurrent isotretinoin as part of clinical treatment

PATIENT CHARACTERISTICS:

• Not pregnant
• Fertile patients must use effective contraception
• Has a single- or double-lumen central venous catheter in place

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics