The influence of red blood cell transfusions on the progression-free survival of patients with localized squamous cell carcinoma of the anus treated with definitive chemoradiation

Background: Red blood cells transfusions (RBCT) have been associated with worse oncological outcomes in distinct tumor types. Inhibition of the activities of Natural Killer (NK) and cytotoxic T cells are the supposed mechanisms underlying a transfusion-related immune modulation. Because the impact of RBCT on the outcomes of patients with squamous cell carcinoma of the anus (SCCA) is uncertain, we aimed to evaluate its influence on the progression-free survival of patients with SCCA treated with definitive chemoradiation (ChRT). Method: ology: This was a retrospective study of consecutive SCCA patients treated with definitive ChRT. The primary endpoint was progression-free survival according to receipt of at least one unit of RBCT. Univariate and multivariate Cox regression analyses for progression-free survival were performed to evaluate prognostic factors. Results: : From February 2003 to April 2018, 136 patients were included. The median age was 59 years, 77.2% was female and 13.9% had HIV infection. Transfused patients were more frequently female and had stage III tumors. Thirty-one (22.8%) patients received a RBCT, increasing the mean hemoglobin levels from 7.6 to 8.5g/dl. With a median follow-up time of 48 months, the median progression-free survival was 36.5 versus 146.9 months for transfused and non-transfused, respectively. In the multivariate analysis, RBCT ([HR]: 6.7 [IC] 95% 3.4-13.2, p<0.001) and stage III (HR: 3.0 [IC] 95% 1.4-6.5, p =0.005) were associated with inferior progression-free survival as compared to non-transfused and stage I-II, respectively. While the rates of complete responses and persistent local disease were similar between the groups, receipt of RBCT was significantly associated with progression (69.2% versus 14.9%; p < 0.00001). Conclusion: Our study suggests that the receipt of RBCT and clinical stage III disease were significantly associated with inferior progression free survival. RBCT or persistent anemia after transfusion did not influence the rates of complete response, but patients who received RBCT presented significantly higher rates of tumor progression.