Prognostic influence of blood transfusion on minimal residual disease in resected gastric cancer patients.

Background: The effect of blood transfusion on prognosis of resected cancer patients has been debated controversially. Therefore, we raised the hypothesis that transfusion-associated immunomodulation affects minimal residual disease after curative tumour resection, an unknown and uncontrolled phenomenon in all former studies which might significantly influence long-term prognosis.

Patients And Methods: 104 patients of a prospective study with curatively resected gastric cancer were stratified according to the immunocytochemical detection of disseminated tumour cells in bone marrow and the prognostic impact of allogeneic blood transfusion was tested. Multiple sequential bone marrow aspirations during follow-up were performed in 74 patients to investigate the blood transfusion effect on long-term development of this systemic disease component.

Results: Whereas in patients with tumour cell detection in bone marrow a significant association of blood transfusion and survival was seen (P = 0.048; relative risk 2.91; 95% CI 1.51-5.61), this was not found in patients without disseminated tumour cells (P = 0.129). Quantitative development of tumour cells in bone marrow during follow-up demonstrated a significant quantitative increase of tumour cells in transfused patients only (P = 0.028).

Conclusion: These findings might explain the contradictory results of recent studies and suggest that the prognostic effect of transfusion is mediated through an impact on minimal residual disease in resected cancer patients.