Relationship between blood transfusion and tumour behaviour.

Blood transfusion results in significant alterations in some parameters of immune function. Because some human cancers appear to stimulate immune responses and may be influenced by host immunity, the possibility arises that transfusion could alter the behaviour of tumours. Experimental studies indicate that allogeneic transfusion can directly alter tumour growth in some circumstances, but at present studies of human cancers do not provide evidence of a causal association between transfusion and tumour growth.