Removal of tumour cells from bone marrow: an evaluation of the available techniques.

Autologous bone marrow transplantation has offered a way of increasing the dose of drugs and radiotherapy which can be used to treat patients with malignant disease in an attempt to eradicate tumour. Bone marrow is taken prior to treatment and returned to the patient to 'rescue' haemopoietic function after ablative therapy is completed. Bone marrow removed for autograft may be contaminated with tumour cells at the time of harvest, and it is undesirable to return these to patients even though there are little data available concerning the number of tumour cells necessary to reseed various malignancies. This review considers the various methods available for removing tumour cells from bone marrow destined for autologous transplantation, and evaluates their advantages and disadvantages.