AB014. Effective somatostatin analogs in a case of advanced thymoma with no uptake in the octreotide scan

Background Management of advanced malignant thymoma is very challenging due to the lack of evidence from randomized trials. Despite advanced and non-curable status, most patients achieve long survival and they usually receive several treatment lines along their disease. There is no standard second line, and toxicity of chemotherapy (CT) should be considered for these long survivors. Treatment with somatostatin analogs showed efficacy in patients with refractory recurrent and/or metastatic thymomas. Case Description In January 2010, a 31-year-old woman was diagnosed of a mass in the anterior mediastinum with a biopsy compatible with thymoma B3 and myasthenia gravis. Thymoma was resected after 2 cycles of neoadjuvant CT with acronym: cisplatin, doxorrubicin, vincristine and cyclophosphamide (ADOC) schedule, then she received additional adjuvant ADOC. Disease progressed on November 2012 with pleural implants and lung nodule in upper right lobe. After 6 cycles of systemic CT with carboplatin and etoposide and major partial response, she was operated on twice on November 2013 and March 2014 with resection of residual disease in lung and pleura. After new pleural disease progression 14 months later (May 2015), new surgical resection was dismissed and received several rounds of retreatment with carboplatin and etoposide with rest periods between them. After each course of this CT, the patient presented a tumor response, but in the last cycles she began to present significant bone marrow toxicity. After the last significant progression in November 2021, it was decided to assess a low-toxic treatment alternative to CT, and despite no uptake in the octreotide scan, octreotide 30 mg IM every 28 days was started achieving stable disease according to RECISTv1 criteria (progression-free interval of 9 months to date) and good tolerance. Diagnosis: long survivor patient with advanced thymoma with pleural relapsing disease treated with several rounds of chemotherapy and response to octreotide instead of no uptake in the octreotide scan. Conclusions Somatostatin analogs can be a low-toxic treatment option in pretreated advanced thymoma patients regardless the octreotide scan uptake. This treatment should be studied in prospective clinical trials.