[Changes in the mean corpuscular volume during the cytotoxic treatment of cancer and risk of secondary leukemia. Preliminary results].

Changes in mean corpuscular volume (MCV) were studied in cancer patients. Vitamin B12 or erythrocyte folate deficiencies were observed in only 9% of macrocytic patients (MCV greater than or equal to 100 fl). Bone marrow study in seven macrocytic patients with normal hemograms and normal levels of vitamin B12 and folic acid, on per os daily cyclophosphamide single agent therapy, showed myelodysplastic features. The highest MCV and MCV increases during therapy among 203 patients were observed in those cancers and cytotoxic therapies most commonly followed by secondary leukemia: Hodgkin's disease treated with MOPP and radiotherapy, and multiple myeloma and ovarian cancer treated with Melphalan. 21 patients who developed secondary leukemia had a higher MCV and a greater MCV increment than the control patients. Differences were significant in Hodgkin's disease. This preliminary report strongly supports monitoring MCV changes during cytotoxic therapy to attempt identification of patients at high risk of secondary leukemia.