B lymphocyte changes induced by peri-operative blood transfusions and surgery in patients with colorectal cancer.

Seventy patients with Duke's C adenocarcinoma scheduled to undergo surgery were divided into two groups, those who received no peri-operative transfusion (Group I, 26 patients) and those who received an average of 2.1 units of packed red blood cells per person peri-operatively (Group II, 44 patients). Immunological parameters were tested 1 week before and 1 and 5 weeks after surgery in order to determine the influence of the transfusion of these parameters. Comparison of the mean values obtained before operation with those obtained one week post-operatively revealed a significant change in the number of B cells (P = 0.014), with a decrease in Group I and an increase in Group II, which was seen to persist for the mean values obtained 5 weeks after surgery. The higher rates of recurrence and the lower rates of survival reported in patients who received transfusion may be related to an as yet unidentified role of B cells or a subpopulation in the immune system, manifested in the suppression of activity of those components responsible for destroying micrometastases. In relation to the site of the tumor no definite conclusions can yet be drawn as to the prognostic importance of our findings concerning the immunological parameters.