Prognostic influence of macrophages in patients with diffuse large B-cell lymphoma: a correlative study from a Nordic phase II trial

Abstract

impact in DLBCL. [14][15][16][17] Of the macrophages, classically activated M1 type TAM have been described as "good", acting to prevent the growth of tumor tissue, whereas the alternative M2 type TAM may have an opposite effect promoting angiogenesis and tumor development. [18][19][20] Importantly, however, studies in follicular lymphoma have demonstrated that the prognostic significance of the tumor microenvironment and especially macrophages is highly dependent on a given therapy. [21][22][23] In the present study, we investigated how the combination of rituximab with chemotherapy influences non-malignant inflammatory cell-associated clinical outcome in DLBCL. Among all studied markers for macrophages, dendritic, and lymphoid cells, we found that pretreatment gene expression of a macrophage marker CD68 and immunohistochemically defined CD68+ TAM content had a positive prognostic impact on the survival of DLBCL patients treated with chemoimmunotherapy, whereas in patients treated without rituximab, CD68 + TAM content was associated with a poor outcome. Methods Patients and samplesThe screening cohort consisted of prospectively collected DLBCL patients who were less than 65 years old and had primary high-risk (age-adjusted IPI score 2-3) disease. They were treated in the Nordic phase II NLG-LBC-04 protocol with dose-dense chemoimmunotherapy followed by systemic central nervous system prophylaxis. 24 The patients in this correlative study represent a subset of patients in the main clinical trial and were selected on the basis of DLBCL histology, the availability of fresh frozen tissue for RNA extraction and exon arrays (gene expression cohort; n=38) and formalin-fixed, paraffin-embedded lymphoma tissue containing adequate material for the preparation of tissue microarrays (TMA; immunohistochemistry cohort; n=59), and the patients' consent to correlative studies. Details of the screening cohort are provided in Table 1, the Online Supplementary Material and Online Supplementary Table S1.The clinical protocol and sampling were approved by Institutional Review Boards, National Medical Agencies and Ethics Committees in Denmark, Finland, Norway and Sweden, and the trial was registered at ClinicalTrials.gov, number NCT01502982.To validate the findings, three independent retrospective series of chemoimmunotherapy-treated DLBCL patients were used. In order to confirm gene expression data, we used RNA sequencing data from 92 patients generated by the Cancer Genome Characterization Initiative (CGCI; dbGaP database applied study accession: phs000532.v3.p1) 25,26 and oligonucleotide-based microarray data from 233 DLBCL patients generated by the Lymphoma/Leukemia Molecular Profiling Project (LLMPP; GEO dataset: GSE10846).10 Both cohorts are subsets of the original study populations treated with a R-CHOP-like regimen based on the availability of complete expression data and clinical information (Online Supplementary Table S2).In order to confirm the immunohistochemical data, an independent population-based series of ...

Tumor-associated macrophages in diffuse large B-cell lymphoma

“…6 The cohorts under study include patients with gene expression data from a Nordic phase II trial (dose-dense chemoimmunotherapy with central nervous system prophylaxis, n=38), 7 from the Cancer Genome Characterization Initiative (R-CHOP, n=92) and from the LLMPP (R-CHOP, n=233 and CHOP, n=181). Immunohistochemistry data were generated using the KP1 anti-human CD68 antibody and positive cells were counted manually.…”

Role of the tumor microenvironment in mature B-cell lymphoid malignancies

“…2,17,18 Riihijarvi et al found that both CD68 mRNA levels and CD68 + tumorassociated macrophages, detected by immunohistochemistry, were adverse prognostic factors for overall survival among patients treated uniformly with chemotherapy in a prospective clinical trial. 19 In contrast, among patients treated with chemo-immunotherapy, the impact of CD68 + tumor-associated macrophages was reversed, such that patients with high CD68 + tumor-associated macrophages had improved overall survival. This interesting observation led the authors to speculate that rituximab may alter the function of tumor-associated macrophages from having a pro-survival effect to an anti-tumor one.…”

Prediction of survival of diffuse large B‐cell lymphoma patients via the expression of three inflammatory genes

“…Recent studies demonstrated the important function of TAMs in the progression of cancers 15, 16, 17, 30. Hans et al.…”

“…It is demonstrated that macrophages possess anti‐tumor or tumor‐promotion effects, depending on their acquired immune‐phenotype (M1 or M2) which express different levels of chemokines, cytokines. TAMs (M2 phenotype) predict poor outcome in DBLCL patients‐treated with chemotherapy 15, 16, 17. Polymorphisms of host cytokines and immunity‐related genes were reported to play very important roles in predicting survival of DLBCL patients 7.…”