[Mini-transplantation for solid tumors]

With the hypothesis that RIST might be useful to induce immunological antitumor effect without excessive toxicities, we evaluated 27 patients(median age 38 years, range 4-59) with refractory non-renal solid tumors, who underwent RIST from the family donors. The primary and secondary endpoints included achievement of complete chimerism, and exploratory evaluation of graft-versus-tumor(GVT) effect, respectively. The conditioning regimen comprised purine analogue and busulfan with or without antithymocyte globulin. All patients achieved complete donor chimerism. These data demonstrate that RIST is a sufficient way to induce immune competent cells to patients with solid tumors. Although cases experienced probable GVT effect were observed in selective patients, total benefit for each tumor should be carefully evaluated in specific phase II-III trials.