Chemotherapy

Vinblastine and prednisone. Patients with recurrent bone disease that recurs months after vinblastine and prednisone are stopped can benefit from treatment with a reinduction of vinblastine weekly and daily prednisone for 6 weeks. If there is NAD or very little evidence of active disease, treatment can be changed to every 3 weeks, with the addition of oral mercaptopurine nightly.[106]

Vincristine, prednisone, and cytarabine. An alternative treatment regimen for patients with any combination of low-risk disease sites employs vincristine, prednisone, and cytarabine.[108][Level of evidence C3]

Single-agent cytarabine. Single-agent cytarabine at doses of 100 to 170 mg/m2 per day for five days has also proven to be effective.[139]

Cladribine. Cladribine at 5 mg/m2 per day for 5 days per course has demonstrated effectiveness for recurrent low-risk LCH (multifocal bone and low-risk multisystem LCH), with very little toxicity.[109][Level of evidence C3] Cladribine therapy should, if possible, be limited to a maximum of six cycles to avoid cumulative and potentially long-lasting cytopenias.In a study of 44 pediatric patients with low-risk LCH who were treated with cladribine, 5 patients achieved complete remissions after a median follow-up of over 5 years.[140] Grade 3 or higher neutropenia occurred in 32% of patients, and grade 3 or higher lymphopenia occurred in 72% of patients. Patients with stable disease or partial responses after 6 months of treatment may ultimately attain a complete response.

Clofarabine. Clofarabine is a proven effective therapy for patients with multiple relapses of low-risk or high-risk LCH.[141][Level of evidence C3]

Hydroxyurea, alone or in combination with oral methotrexate. In one single-center trial, treatment with hydroxyurea, alone or in combination with oral methotrexate, reported the following results:[87][Level of evidence C3]

Hydroxyurea, alone or in combination with oral methotrexate. In one single-center trial, treatment with hydroxyurea, alone or in combination with oral methotrexate, reported the following results:[87][Level of evidence C3]

Twelve of fifteen patients with low-risk recurrent LCH had responses to treatment.

Thalidomide. A phase II trial of thalidomide in patients with LCH (ten low-risk patients; six high-risk patients) who failed primary treatment and at least one secondary regimen demonstrated the following:[88][Level of evidence C3]

Thalidomide. A phase II trial of thalidomide in patients with LCH (ten low-risk patients; six high-risk patients) who failed primary treatment and at least one secondary regimen demonstrated the following:[88][Level of evidence C3]

Of the ten low-risk patients, four had complete responses and three had partial responses. Complete response was defined as healing of bone lesions on plain radiographs (n = 3) or complete resolution of skin rash (n = 4, including 3 with bone lesions that had complete resolution). Partial response was defined as healing of a bone lesion, but then worsening of a skin rash that was partially resolved.

Thalidomide. A phase II trial of thalidomide in patients with LCH (ten low-risk patients; six high-risk patients) who failed primary treatment and at least one secondary regimen demonstrated the following:[88][Level of evidence C3]

Dose-limiting toxicities, such as neuropathy and neutropenia, may limit the overall usefulness of thalidomide.

Thalidomide. A phase II trial of thalidomide in patients with LCH (ten low-risk patients; six high-risk patients) who failed primary treatment and at least one secondary regimen demonstrated the following:[88][Level of evidence C3]

Thalidomide is not a significant agent in treating pediatric patients.