Therapy-related myelodysplastic syndrome as a late adverse event of definitive chemoradiotherapy for esophageal and oropharyngeal cancer

Abstract

The risks of myelodysplastic syndrome (MDS) and acute leukemia are increased in patients previously treated for other malignancies. Therapy-related MDS (t-MDS) occurs after exposure to certain cytotoxic agents or radiation used for cancer treatment. We report a case of t-MDS following curative chemoradiotherapy (CRT) for esophageal and oropharyngeal cancer. An 80-year-old male diagnosed with double cancers of the esophagus and oropharynx underwent definitive CRT and achieved a complete response. Six years later, he became anemic, and bone marrow examination showed 3.4% blast cells with fine chromatin structures and basophilic cytoplasm. Cytogenetic analysis indicated a complex karyotype that included chromosome 5 and 7 abnormalities. These findings were consistent with t-MDS. Subsequently, he developed acute myeloid leukemia and died 8 months later. This case indicates that long-term surveillance is needed to closely monitor the risk of t-MDS in patients treated with CRT.