Dose-dense Chemotherapy for Disseminated Thymoma Reported

Researchers from Japan have reported that dose-dense chemotherapy is effective for the treatment of patients with Stage IV thymoma. The details of this study appeared in the November 4, 2009 issue of the British Journal of Cancer.[1]

Thymomas are the most common tumor arising in the anterior mediastinum. Thymomas can be associated with systemic diseases such as myasthenia, polymyositis, lupus erythematosus, rheumatoid arthritis, thyroiditis, Sjogren's syndrome, and hypogammaglobulinemia. The management of patients with thymoma has recently been reviewed in the Journal of Thoracic Oncology.[2] Surgery alone is the treatment of choice for patients with Stage I disease, while surgery plus radiotherapy is recommended for high-risk Stage II disease. Stage III patients are treated with adjuvant and/or neoadjuvant therapy, which can include both chemotherapy and radiotherapy. One study reported good results with neoadjuvant and adjuvant chemotherapy with cisplatin, epidoxorubicin, and etoposide followed by radiotherapy and surgery.[3]

Patients with Stage IV disease are treated with chemotherapy. Platinum and anthracyclines compounds and etoposide appear to be the main chemotherapy drugs used to treat disseminated thymomas. Some thymomas appear to respond to prednisone, and there have been reports of responses to the newer targeted agents.

Thirty patients in the current study had Stage IVA or IVB thymoma without prior therapy. Patients with thymic carcinoma, carcinoid, and lymphoma were excluded from this study. Patients received nine weeks of therapy with vincristine, doxorubicin, and etoposide supported by granulocyte colony-stimulating factor (G-CSF).  Etoposide and doxorubicin were given on weeks 1, 3, 5, 7, and 9, while vincristine was given on weeks 1, 2, 4, 6, and 8. The overall response rate was 59% with no complete responses. Median progression-free survival was 0.79 years. Progression-free survival at two years was 15%. Overall survival at two years was 89%, and the five-year survival was 65%. These authors concluded: “In Stage-IV thymoma patients, weekly dose-dense chemotherapy offers similar activity to conventional regimens.”

Comments: These data suggest that a combination chemotherapy is effective palliation for patients with disseminated thymoma. The dose-dense regimen described here appeared to be well tolerated with G-CSF support without treatment-related mortality.

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