Abstract 5791: Blood transfusions may adversely affect survival outcomes of patients with lung cancer: A systematic review and meta-analysis

Background: Lung cancer has the highest mortality rate among tumor entities in the United States. Patients with lung cancer may require transfusions due to blood loss during surgery or bone marrow suppression caused by chemoradiation. Despite common use in practice, however, the impact of blood transfusions on prognosis among patients with lung cancer remains unclear. There have been long-standing concerns on the associated risk, including possible contamination by undetected malignant cells. The concept of transfusion-related immunomodulation (TRIM) has also been highlighted, which hypothesizes that transfusions may suppress the anti-tumor immune surveillance and promote growth of cancer cells. In spite of these concerns, scholarly efforts elucidating the relationship between transfusions and cancer recurrence have focused primarily on other cancers such as colorectal cancer. We thus performed an updated systematic review and meta-analysis to evaluate the influence of blood transfusions on survival outcomes of lung cancer patients. Methods: We searched PubMed, Embase, Cochrane Library, and Ovid MEDLINE for publications illustrating the association between blood transfusions and prognosis among people with lung cancer from inception to 11/28/2019. Overall survival (OS) and disease-free survival (DFS) were the outcomes of interest. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using the random-effects model. Study heterogeneity was evaluated with the I2 test. Publication bias was explored via funnel plot and trim-and-fill analyses. Results: We identified 843 citations initially and four studies were added after reviewing references of the searched articles. By assessing titles and abstracts, we excluded 393 duplicates and 414 irrelevant articles. 16 studies were removed given that they were review or correspondence articles or lacked the outcome of interest. As a result, 24 cohort studies with 13,036 patients (3,098 cases and 9,938 controls) were included for meta-analysis. Among these records, 23 studies investigated the effect of perioperative transfusions, while one examined that of transfusions during chemotherapy. Two studies suggested the possible dose-dependent effect in accordance with the number of transfused units. In pooled analyses, blood transfusions deleteriously influenced both OS (HR=1.36, 95% CI=1.14-1.62, P=0.0005, I2=0%) and DFS (HR=1.46, 95% CI=1.16-1.84, P=0.0013, I2=0%) of people with lung cancer. No evidence of significant publication bias was detected in funnel plot and trim-and-fill analyses (OS: HR=1.26, 95% CI=1.07-1.48, P=0.0052; DFS: HR=1.36, 95% CI=1.10-1.69, P=0.0053). Conclusion: Blood transfusions were associated with decreased survival of lung cancer patients. Citation Format: Sukjoo Cho, Jonghanne Park, Misuk Lee, Dongyup Lee, Horyun Choi, Gahyun Gim, Leeseul Kim, Cyra Y. Kang, Young Kwang Chae. Blood transfusions may adversely affect survival outcomes of patients with lung cancer: A systematic review and meta-analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5791.