Treatment of Adult LCH
A variety of chemotherapy regimens, including 2-CdA have been published in a relatively limited number of patients. (Refer to the Chemotherapy section of this summary for more information.)
Anecdotal reports have described the successful use of the bisphosphonate pamidronate in controlling severe bone pain in patients with multiple osteolytic lesions.[4,5,6] Successful use of oral bisphosphonates have also been described and may be a useful and relatively low-toxic way of treating adult bone LCH. In view of the increased toxicity of chemotherapy in adults, bisphosphonate therapy could be used prior to chemotherapy in multifocal bone disease. Response of other organs, such as skin and soft tissue, to bisphosphonate therapy has been reported.
Another approach using anti-inflammatory agents (pioglitazone and rofecoxib) coupled with trofosfamide in a specific timed sequence was successful in two patients with disease resistant to standard chemotherapy treatment.
Treatment of single-system skin disease
- Localized lesions can be treated by surgical excision, but as with bone, mutilating surgery, including hemivulvectomy, should be avoided unless the disease is refractory to available therapy.
- Topical therapies are described in greater detail in the childhood isolated skin involvement section of this summary and include topical or intralesional corticosteroid, topical tacrolimus, imiquimod, and psoralen and long-wave ultraviolet radiation (PUVA). Therapies such as PUVA may be more useful in adults where long-term toxicity may be less of a consideration.[10,11,12]
- Systemic therapy for severe skin LCH includes oral methotrexate, oral thalidomide, oral interferon-alpha, or combinations of interferon and thalidomide.[13,14] Recurrences after stopping treatment may occur but may respond to retreatment.
- Oral isotretinoin has achieved remission in some refractory cases of skin LCH in adults.
Chemotherapy for the treatment of single-system and multisystem disease
Chemotherapy is generally used for skin LCH associated with multisystem disease in adults.
- A single-center, retrospective review of 58 adult LCH patients reported on the efficacy and toxicities of treatment with vinblastine/prednisone, cladribine, and cytarabine. Patients treated with vinblastine/prednisone had the worst outcome, with 84% not responding within 6 weeks or relapsing within a year. The no-response/relapse rate was 59% for cladribine and 21% for cytarabine. Grade 3 or 4 neurotoxicity occurred in 75% of patients treated with vinblastine. Grade 3 or 4 neutropenia occurred in 37% of patients treated with cladribine and in 20% of patients receiving cytarabine.
- Etoposide has been used with some success in single-system and multisystem LCH. Use of prolonged oral etoposide in adults with skin LCH has been reported with minimal toxicity, while 3-day courses of intravenous etoposide 100 mg/m2 /day achieved complete remission in a small number of patients with resistant single-system and multisystem disease. Another study at the same center found that azathioprine was the most successful drug for localized disease in adults with the addition of etoposide for refractory and multisystem disease.
- For patients who do not respond to front-line therapy with etoposide, 2-CdA is effective for adults with skin, bone, lymph node, and probably pulmonary and central nervous system (CNS) disease.[19,20] The first study that used 2-CdA to treat refractory and recurrent skin LCH disease reported on three patients (ages 33, 51, and 57 years) who received two to four courses of 2-CdA at 0.7 mg/kg intravenously over 2 hours/day for 5 days. In a series of five adults (one untreated and four with refractory LCH treated with 2-CdA at the same dose noted above), three patients achieved a complete remission and two patients achieved a partial remission.
- An adult lymphoma treatment regimen, MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone and bleomycin), was used in three patients with multisystem LCH and four with single-system multifocal bone LCH from 1995 to 2007. Total duration of therapy was 12 weeks, response was seen in all patients, two with partial response and five with complete response. Three recurrences were seen after stopping therapy. Despite the small number of patients and the retrospective nature of the study, MACOP-B may be useful as salvage therapy in adult patients with LCH and deserves further study.
- Anecdotal reports have described the successful use of the bisphosphonate pamidronate in controlling severe bone pain in patients with multiple osteolytic lesions.[4,5,6]
- Imatinib mesylate has been effective in the treatment of four adult LCH patients who had skin, lung, bone, and/or CNS involvement.[23,24] Another adult LCH patient did not respond to imatinib mesylate.
- A case report suggests some benefit to treating neurodegenerative CNS LCH disease with infliximab, a tumor necrosis factor-alpha inhibitor.