Non-myeloablative allogeneic stem cell transplantation in patients with solid tumours and patients with a haematological malignancy

Allogeneic stem cell transplantation (allo-SCT) is a treatment option for several haematological tumours, not only to regain haematopoiesis after myeloablative chemotherapy and/or radiotherapy, but also for its apparent antitumour effect. This so-called graft-versus-tumour effect might not only be effective against haematological tumours, where it has best been proven, but also against solid tumours. To reduce morbidity and treatment-related mortality of allo-SCT, efforts are being made to establish engraftment of allogeneic stem cells after a non-myeloablative conditioning regimen and create a 'mini transplantation'. Such a therapy relies more heavily on the graft-versus-malignancy effect than on the antitumour effect exerted by the chemotherapy/ radiotherapy. Here, we report the outcomes of 15 patients with haematological disease or solid tumours who underwent an SCT in the University Hospital Maastricht after a non-myeloablative fludarabine/cyclophosphamide conditioning regimen. Although results are promising, adjustments will be needed to ensure long-term stable engraftment and optimise the antitumour effect.