Pirfenidone in Treating Young Patients With Neurofibromatosis Type 1 and Plexiform Neurofibromas

DISEASE CHARACTERISTICS:

* Diagnosis of neurofibromatosis type 1 (NF1) AND
* Plexiform neurofibromas

  * Neurofibromas that have grown along the length of a nerve and may involve multiple fascicles and branches (spinal neurofibromas involve 2 or more levels with connection between the levels or extending laterally along the nerve)
  * Potential to cause significant morbidity such as:

    * Head and neck lesions that could compromise airway or great vessels
    * Brachial or lumbar plexus lesions that could cause nerve compression and loss of function
    * Lesions that could result in major deformity (e.g., orbital lesions) or significant cosmetic problems
    * Lesions of the extremity that cause limb hypertrophy or loss of function
    * Painful lesions
* Meets at least 1 other diagnostic criteria for NF1

  * 6 or more cafe-au-lait spots (at least 0.5 cm in prepubertal patients or at least 1.5 cm in postpubertal patients)
  * Freckling in the axilla or groin
  * Optic glioma
  * 2 or more Lisch nodules
  * Distinctive bony lesion (dysplasia of the sphenoid bone or dysplasia or thinning of long bone cortex)
  * First-degree relative with NF1
* Measurable plexiform neurofibromas

  * At least 3 cm in 1 dimension
  * Tumor resection not feasible
* No history of malignant peripheral nerve sheath tumor or other cancer
* No evidence of an active optic glioma requiring chemotherapy or radiotherapy
* No malignant glioma

PATIENT CHARACTERISTICS:

Age

* 3 to 21

Performance status

* Karnofsky 50-100% (over 10 years of age)
* Lansky 50-100% (10 years and under)

Life expectancy

* Not specified

Hematopoietic

* Absolute granulocyte count at least 1,500/mm\^3
* Hemoglobin at least 9.0 g/dL
* Platelet count at least 150,000/mm\^3

Hepatic

* Bilirubin normal
* SGPT no greater than 2 times upper limit of normal
* No clinically significant hepatic dysfunction that would preclude study participation

Renal

* Creatinine normal for age OR
* Creatinine clearance at least 70 mL/min

Cardiovascular

* No clinically significant cardiac dysfunction that would preclude study participation

Pulmonary

* No clinically significant pulmonary dysfunction that would preclude study participation

Other

* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 2 months after study
* Must be able to take pirfenidone orally
* No serious infections
* No clinically significant unrelated systemic illness or organ dysfunction that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

* At least 30 days since prior immunotherapy
* No concurrent immunotherapy
* No concurrent hematopoietic growth factors

Chemotherapy

* At least 30 days since prior chemotherapy
* No concurrent chemotherapy directed at the tumor

Endocrine therapy

* At least 30 days since prior hormonal therapy directed at the tumor
* No concurrent hormonal therapy directed at the tumor

Radiotherapy

* At least 90 days since prior radiotherapy to the site of the plexiform neurofibroma
* No concurrent radiotherapy directed at the tumor

Surgery

* Not specified

Other

* Recovered from prior therapy
* More than 30 days since prior investigational agents
* No prior pirfenidone
* No other concurrent investigational agents