Hematological Changes Mimicking Myelodysplastic Syndrome Following Treatment for Osteosarcoma

Therapy-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/AML) is a feared long-term complication of pediatric cancer. Few osteosarcoma patients develop t-MDS/AML, but the frequency of hematological abnormalities after therapy is unknown. We reviewed biochemistry from osteosarcoma patients up to 3 years posttreatment.

All children diagnosed with osteosarcoma at our department from 2006 to 2012 without relapse 1 month posttherapy were included (n=14). Serial blood counts posttherapy were analyzed.

The median increase of mean corpuscular volume (MCV) from baseline was 8 fL 6 months posttherapy and remained >5 throughout follow-up. All posttreatment levels of MCV were above 90 fL in 5 patients. Six months posttherapy, the median difference for platelets, white blood count, and absolute neutrophil count had decreased from baseline. They remained under baseline throughout follow-up. Hemoglobin remained stable. Ferritin level was associated with increased MCV. MDS with monosomy 7 was diagnosed in 1 patient. Hypoplastic refractory cytopenia was found in another patient showing spontaneous normalization of hematologic values.

More than a third of patients treated for osteosarcoma developed hematological abnormalities mimicking early MDS, but only 1 developed t-MDS/AML. Close hematological monitoring of patients recovering from osteosarcoma is essential and it is worth noting that hematological abnormalities are frequent and may be transitory.