A study, led by Dr. Joan Blad?, researcher of the Haematooncology Group of Hospital Cl?nic-IDIBAPS (Barcelona), in collaboration with Dr. Laura Rosi?ol, researcher of the same group, assessed the efficiency in terms of response and survival of autologous bone marrow transplantation in patients suffering from refractory myeloma previously having undergone high-dose chemotherapy (HDT).
Results were conclusive; in patients suffering from resistant myeloma, neither did transplantation show any benefits nor increased survival.
This research work, conducted within the frame of the PETHEMA network, was carried out from October 1999 to December 2000. It was coordinated from Hospital Cl?nic, Barcelona and had the participation of the six following Spanish hospitals: Hospital Cl?nico de Salamanca, Hospital de Sant Pau, Hospital Son Dureta Palma de Mallorca, Hospital Universitario de Salamanca, Hospital Ram?n y Cajal de Madrid, Hospital La Fe de Valencia. A total of 829 patients under 65 years and suffering from newly diagnosed multiple myeloma underwent 6 chemotherapy treatment cycles.
Firstly, researchers observed that approximately 10% of patients treated with chemotherapy did not respond to the therapy. The group of treated patients suffering from refractory myeloma was divided into two separately investigated subgroups. The first, formed by 62 % of the total number of patients, consisted of refractory patients presenting a stable, non-progressing disease. The second group, the remaining 38%, suffered from progressive disease. Until now, it was believed that the fraction of patients which did not show any response to prior treatment was the most benefited group from subsequent transplantations. Nevertheless, results obtained by this trial unveiled a different idea. After conducting subsequent autologous bone marrow transplantations in all patients, researchers observed that refractory patients suffering from progressive myeloma did not show any benefit regarding survival. The disease progressed despite of the transplantation. On the other hand, the second group suffering from stable, non-progressive myeloma responded slightly and showed a life time expectancy of 5 more years. This last survival piece of data, a priori interesting, is very similar that obtained from the group of 718 patients which showed response to chemotherapy (HDT). Thus, it still remains to determine whether this improvement of survival in the second group is due to the transplantation, the chemotherapy treatment or to patient?s indolent myeloma.