Abstract 2371: The number of CD163-positive cells in the microenvironment and peripheral blood lymphocyte-to-monocyte-ratio (LMR) is associated with poor outcome in patients with diffuse large B-cell lymphoma (DLBCL)

Purpose: Despite advances in treatment, 30-40% of the DLBCL patients succumb to their disease. The prognostic role of peripheral blood absolute monocyte count (AMC), LMR and tumor-associated macrophages (TAM) in DLBCL has previously been suggested. However, information on the association of LMR/AMC and TAM is limited. We performed this study to evaluate the association and prognostic role of LMR/AMC and TAM in patients with DLBCL treated at our institute. Patients and Method: 76 patients with newly diagnosed DLBCL were selected. CD163 expression was assessed by immunohistochemistry using tissue microarray. The number of CD163 positive nucleated cells at objective magnification of 40x were counted and were divided into 4 categories: score 0 (0-25 cells); score 1 (26-50); score 2 (51-75); score 3 (>75). Results: The median age of the patients was 62 (range: 27-87) years-old. 38 patients (52.4%) were advanced stage (stage 3/4), and 47.3% of patients had germinal center (GC) phenotype. The median AMC at the time of diagnosis was 408 (range: 42-1,107)/mm 3 , and the median LMR was 2.94 (0.64-14.06). CD163 staining was scored as follows: score 0: 13 patients (17.1%), score 1: 7 patients (9.2%), score 2: 6 patients (7.9%), score 3: 50 patients (65.8%). There was a trend for higher stage (p = 0.08) and non-GC type histology (p = 0.05) in patients with CD163 score 3. Although there was no difference in AMC between those with CD163 score 0-2 and 3, CD163 score 3 was significantly associated with lower LMR (LMR Of the patients who received treatment (n = 68), 43.4% of the patients were treated with a rituximab containing regimen (R(+)). 16 (R(+):5, R(-):11) patients died after a median observation of 6.2 (0.1-21.6) years. LMR Conclusion: We have confirmed in our patients with newly diagnosed DLBCL who received chemotherapy without rituximab, that LMR and the number of CD163-positive cells are significant prognostic factors. Contrary to previous reports, neither TAM as characterized by CD163-positive cells in the microenvironment or LMR/AMC were prognostic factors in R(+) patients. Of interest, higher number of TAM was associated with lower LMR. Further evaluation is needed to confirm this finding and its clinical relevance. Citation Format: Eri Matsuki, Olga L. Bohn, Janine Pichardo, Andrew Zelenetz, Anas Younes, Julie Teruya-Feldstein. The number of CD163-positive cells in the microenvironment and peripheral blood lymphocyte-to-monocyte-ratio (LMR) is associated with poor outcome in patients with diffuse large B-cell lymphoma (DLBCL). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2371. doi:10.1158/1538-7445.AM2015-2371