Fractionated TBI and methotrexate-cyclosporin do not seem to increase relapses in BMT for first chronic phase CML patients: results of a single centre study.

Fractionated total body irradiation (FTBI) and methotrexate-cyclosporin A(MTX-CSA) have been found useful in reducing interstitial pneumonia (IP) and acute graft-versus-host-disease (GVHD) in bone marrow transplantation patients, but an increase in relapse rate has been observed by some authors when these strategies are used. To evaluate this relapse risk, we performed a retrospective analysis in 24 consecutive first chronic phase chronic myeloid leukemia patients who received an HLA-identical non-T cell-depleted graft in a single institution. All were conditioned with cyclophosphamide plus FTBI (12 Gy in six fractions delivered twice daily for 3 days) (CY-FTBI) and received MTX-CSA as GVHD prophylaxis. Serial hematologic and cytogenetic bone marrow analysis were performed at least three times (days +30, +100, +360) and at variable intervals thereafter in long-term survivors. Actuarial probabilities of developing IP and acute GVHD greater than or equal to II were respectively 5.9% and 44.2%, with a GVHD-associated mortality of 33%. Four-year actuarial relapse and disease-free survival rates were 7.7% and 48.2% respectively. No exclusively cytogenetic relapses were observed. Our results suggest that CY-FTBI and MTX-CSA are not associated with an increase in relapse rate in 1CP-CML patients.