[Azacitidine for Therapy-Related Myelodysplastic Syndrome Following Oxaliplatin (L-OHP)Therapy for Metastatic Rectal Cancer].

Therapy-related myelodysplasticsyndrome(t-MDS)has been reported to occur after treatment with cytotoxic agents and radiation. Here, we report a case of t-MDS following oxaliplatin(L-OHP)exposure, which was successfully treated with azacitidine(AZA). A 71-year-old man was referred to our department because of pancytopenia. He had been diagnosed with rectal cancer(cT4aNXM0, stage II B-III C, RAS gene status wild-type)3 years ago and had received 8 courses of capecitabine(CAP)and L-OHP(XELOX regimen), followed by 48 courses of CAP and bevacizumab. Before referral, recurrence of rectal cancer was detected using CT after the last course of chemotherapy. A bone marrow examination revealed multilineage dysplasia and 9.0%myeloblasts. Cytogenetic analysis disclosed a chromosome 7 abnormality. The diagnosis of t- MDS was made and treatment with AZA was initiated. Subsequently, temporary but significant hematological improvements were observed, which enabled the patient to receive additional palliative radiation therapy against the locally relapsed rectal cancer. AZA might be useful in t-MDS because of its efficacy and low toxicity.