The Effectiveness and Tolerance of TS-1 a Monotherapy for Relapsed Thymic Cancer Patient Who could not Tolerate Platinum Compounds

Background: The optimal chemotherapeutic regimens for thymic cancers still remain controversial, although systemic chemotherapy is an important therapeutic modality for unresectable thymic cancer. In general, platinumbased regimens such as CODE and ADOC are widely used. However, several serious side effects of the platinum therapy may significantly restrict its efficacy for clinical application. We herein describe a case with a good response to TS-1 treatment for relapsed thymic cancer in a patient who could not tolerate platinum compounds. Case report: A 73-year-old woman was diagnosed with thymic cancer, Masaoka stage IVa, in May 2009. She underwent the concurrent chemoradiation therapy. In September 2011, lung metastasis of the thymic cancer was noted in the right upper lobe. It was difficult to continue platinum-based chemotherapy due to various life-threatening side effects of the treatment. In June 2013, the chest CT scan revealed the growth of the right upper lobe metastatic tumor and left upper lobe atelectasis due to a metastatic polyploidy lesion in the left upper bronchus. The patient underwent partial resection of the lesion and repeat resections in June and September 2014. At the same time, the right upper lobe metastatic tumor had continued to grow. The patient received chemotherapy with TS-1 monotherapy. There were no severe toxicities and the right upper lobe metastatic tumor showed a marked reduction in size. At present, TS-1 therapy has been continued and the patient remains well with an excellent performance status. Conclusion: TS-1 may be a good alternative treatment for patients who cannot tolerate platinum compounds.