EP1.15-20 Good Control by Re-Administration of Carboplatin and Paclitaxel Against Unresectable Thymic Carcinoma

Abstract

Many chemotherapy regimens have been administered for unresectable and recurrent thymic carcinoma. However, hightly effective standard regimens have not yet been developed. Although carboplatin-based chemotherapy is considered one of the effective options for thymic carcinoma, carboplatin can be used to treat thymic carcinoma up to only 4–6 cycles following guidelines. In addition, there is no scientific evidence for the usefulness of chemotherapy when thymic carcinoma relapses. A 48-year-old man who had an abnormal shadow on a chest radiograph obtained during a medical checkup was referred to our hospital. Chest computed tomography (CT) showed a mass measuring 9.3 cm in the anterior mediastinum. Positron emission tomography (PET)-CT showed significant abnormal uptake with a standardized uptake value of 24.5, and there was no evidence of metastasis. We performed median sternotomy, but found pleural dissemination in the right thoracic cavity. We then only obtained a biopsy. Pathologically he was diagnosed with thymic carcinoma. We administered carboplatin and paclitaxel for up to 6 cycles, combined with radiotherapy (60 Gy/30 fr). Six months later, abnormal uptake on PET-CT almost disappeared. However, one year after the chemoradiotherapy, PET-CT showed recurrence of thymic carcinoma. Therefore, we decided to administer the same regimen again for up to 13 cycles. After re-administration, PET-CT showed markedly decreased accumulation and regression of thymic carcinoma. No severe adverse effects were observed. We have subsequently continued monotherapy containing paclitaxel, and until currently there is no evidence of relapse 23 months after surgery. Carboplatin has no limitations on its cumulative dose according to its drug package insert, unlike in the case of anthracycline, and the total dose is only limited on the basis of increased side effects regardless of its antineoplasmatic effect. We herein report a case of re-administering carboplatin against unresectable thymic carcinoma beyond the dose suggested by guidelines and achieving good progress.