[Incidence of blood transfusion on the development of cancer]

It has been known since 1974 that blood transfusion can depress the immune system, which proved to be a benefit for future renal transplant recipients since transplants were found to be better tolerated after one or several pre-transplantation transfusions. Hence the idea that the immunodepression thus obtained could have deleterious effects on cancer patients operated upon and receiving a blood transfusion during surgery. The first retrospective study, carried out in 1982, showed that among patients with cancer of the colon 84 percent of those who had not been perfused and only 51 percent of those who had been perfused were alive and without recurrence at 5 years. Since this study, numerous reports have been published with conflicting results in patients with cancer of the colon and rectum, as well as uterine cervix, kidney, lung, breast, vulva, stomach, soft tissues and the E.N.T. region cancers. Several hypotheses have been formulated to explain the immunosuppression, ranging from the action of "substances" in the plasma-solution sampling mixe to disorders in eicosanoids metabolism induced by blood perfusion. Today, no firm and definite conclusion can be drawn from these reports, but labile components of blood must always be used with caution.