Refined prognostic role of CD68-positive tumor macrophages in the context of the cellular micromilieu of classical Hodgkin lymphoma

Spindle-shaped CD163+ rosetting macrophages replace CD4+ T-cells in HIV-related classical Hodgkin lymphoma

Combination antiretroviral therapy is highly effective in HIV infection, leading to decreased incidences of AIDS-defining neoplasms. However, HIV patients still have a 10-fold increased risk of developing classical Hodgkin lymphoma compared with the general population. As Hodgkin- and Reed-Sternberg cells represent only a minority in the tumor infiltrate, the aim of the present study was to characterize the microenvironment of HIV-related classical Hodgkin lymphoma and compare it with classical Hodgkin lymphoma cases of immunocompetent individuals. The major morphologic differences were the presence of necrotic foci and the absence of epithelioid cell formation in HIV-related Hodgkin lymphoma. We observed a significantly decreased number of CD4+ T-cells and a significantly increased number of CD163+ macrophages in HIV-related Hodgkin lymphoma. Cases exhibiting a 'sarcomatoid' pattern of the reactive infiltrate exhibited significantly greater numbers of macrophages, associating the 'sarcomatoid' pattern to the presence of spindle-shaped macrophages. Whereas, rosetting of CD4+ T-cells around Hodgkin- and Reed-Sternberg cells was frequently observed in classical Hodgkin lymphoma in immunocompetent persons; rosetting in a subset of HIV-related Hodgkin lymphoma cases appeared to involve cytoplasmic protrusions of spindle-shaped macrophages. HIV-related Hodgkin lymphoma, therefore, is characterized by unique morphologic features, which should be recognized by pathologists.

Prognostic role of tumor-associated macrophages and angiogenesis in classical Hodgkin lymphoma

We studied by immunohistochemistry CD68 + tumor-associated macrophages (TAMs) and angiogenesis in 121 consecutive cases of uniformly treated classical Hodgkin lymphoma (cHL). High TAM count showed a significant correlation with age ≥ 45, mixed cellularity subtype and high β₂-microglobulin level. Vessel density (VD) was unrelated to clinicopathological features, while a significant correlation was found between TAM count and VD. Patients with high TAMs showed a trend toward reduced progression-free survival and significantly shorter overall survival (OS). No correlation was found between VD and survival. At multivariate analysis, bulky disease was an independent predictor of reduced progression-free survival, while independent adverse prognostic factors for OS were male sex, age ≥ 45, advanced stage and bulky disease. High TAM count results in an adverse overall outcome in cHL and is significantly correlated to VD. Since VD has no prognostic relevance, the adverse effect of TAMs is presumably unrelated to angiogenesis.

Tumor-associated macrophages as a prognostic parameter in multiple myeloma

The interaction between multiple myeloma (MM) cells and the bone marrow stroma constitutes the basis of myeloma pathogenesis and has led the way for the corresponding therapeutic strategies. The aim of this study is to evaluate tumor-associated macrophages (TAMs) which is an important element of bone marrow stroma and its prognostic relevance in newly diagnosed MM patients. We also wanted to determine the association between TAMs and microvessel density (MVD). Sixty-eight patients, who were diagnosed with MM at the Department of Hematology, Gazi University Hospital, between January 2000 and January 2011, were reviewed retrospectively. Tumor-associated macrophages were evaluated by staining with anti-CD68 and anti-CD163 monoclonal antibodies, and MVD was evaluated by factor VIII staining. Median age was 60 (range, 40-84) years with 36 males and 32 females. The number of both CD 68+ and CD 163+ cells had a negative impact on OS at 6 years (p = 0.013 vs. 0.036; p = 0.015 vs. 0.039) in univariate and multivariate analysis in which age, sex, ISS, the induction treatment, and response to induction treatment are included as variables. High-grade MVD was found to be associated with increased CD163+ cell count. In conclusion, TAMs seems to be a promising prognostic histopathological marker in newly diagnosed MM patients.

Aberrant T-cell antigen expression in classical Hodgkin lymphoma is associated with decreased event-free survival and overall survival

Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) rarely express T-cell-associated antigens (TCA), but the clinical significance of this finding is uncertain. Fifty cHLs expressing any TCA on the HRS cells (TCA-cHL) were identified in two cohorts (National Cancer Institute, n = 38; Basel, n = 12). Diagnostic pathology data were examined in all cases with additional T-cell receptor γ rearrangements (TRG@) polymerase chain reaction (PCR) in a subset of cases. The outcome data were compared with a cohort of cHLs negative for TCA (n = 272). Primary end points examined were event-free survival (EFS) and overall survival (OS). The median age in the TCA-cHL group was 40 years (range, 10-85 years). Seventy percent presented in low stage (stage I/II) at presentation with nodular sclerosis (NS) histology predominating in 80% of cases. Among the TCA, CD4 and CD2 were most commonly expressed, seen in 80.4% and 77.4% of cases, respectively. TRG@ PCR was negative for clonal rearrangements in 29 of 31 cases. During a median follow up of 113 months, TCA expression predicted shorter OS (adjusted hazard ratio [HRadj] = 3.32 [95% confidence interval (CI): 1.61, 6.84]; P = .001) and EFS (HRadj = 2.55 [95% CI: 1.45, 4.49]; P = .001). TCA-cHL often display NS histology, lack T-cell genotype, and are independently associated with significantly shorter OS and EFS compared with TCA-negative cHLs.

Expression of FOXP3, CD68, and CD20 at diagnosis in the microenvironment of classical Hodgkin lymphoma is predictive of outcome

PURPOSE

The immune microenvironment is key to the pathophysiology of classical Hodgkin lymphoma (CHL). Twenty percent of patients experience failure of their initial treatment, and others receive excessively toxic treatment. Prognostic scores and biomarkers have yet to influence outcomes significantly. Previous biomarker studies have been limited by the extent of tissue analyzed, statistical inconsistencies, and failure to validate findings. We aimed to overcome these limitations by validating recently identified microenvironment biomarkers (CD68, FOXP3, and CD20) in a new patient cohort with a greater extent of tissue and by using rigorous statistical methodology.

PATIENTS AND METHODS

Diagnostic tissue from 122 patients with CHL was microarrayed and stained, and positive cells were counted across 10 to 20 high-powered fields per patient by using an automated system. Two statistical analyses were performed: a categorical analysis with test/validation set-defined cut points and Kaplan-Meier estimated outcome measures of 5-year overall survival (OS), disease-specific survival (DSS), and freedom from first-line treatment failure (FFTF) and an independent multivariate analysis of absolute uncategorized counts.

RESULTS

Increased CD20 expression confers superior OS. Increased FOXP3 expression confers superior OS, and increased CD68 confers inferior FFTF and OS. FOXP3 varies independently of CD68 expression and retains significance when analyzed as a continuous variable in multivariate analysis. A simple score combining FOXP3 and CD68 discriminates three groups: FFTF 93%, 62%, and 47% (P < .001), DSS 93%, 82%, and 63% (P = .03), and OS 93%, 82%, and 59% (P = .002).

CONCLUSION

We have independently validated CD68, FOXP3, and CD20 as prognostic biomarkers in CHL, and we demonstrate, to the best of our knowledge for the first time, that combining FOXP3 and CD68 may further improve prognostic stratification.

Gene expression profiling of microdissected Hodgkin Reed-Sternberg cells correlates with treatment outcome in classical Hodgkin lymphoma

In classical Hodgkin lymphoma (CHL), 20%-30% of patients experience relapse or progressive disease after initial treatment. The pathogenesis and biology of treatment failure are still poorly understood, in part because the molecular phenotype of the rare malignant Hodgkin Reed-Sternberg (HRS) cells is difficult to study. Here we examined microdissected HRS cells from 29 CHL patients and 5 CHL-derived cell lines by gene expression profiling. We found significant overlap of HL-specific gene expression in primary HRS cells and HL cell lines, but also differences, including surface receptor signaling pathways. Using integrative analysis tools, we identified target genes with expression levels that significantly correlated with genomic copy-number changes in primary HRS cells. Furthermore, we found a macrophage-like signature in HRS cells that significantly correlated with treatment failure. CSF1R is a representative of this signature, and its expression was significantly associated with progression-free and overall survival in an independent set of 132 patients assessed by mRNA in situ hybridization. A combined score of CSF1R in situ hybridization and CD68 immunohistochemistry was an independent predictor for progression-free survival in multivariate analysis. In summary, our data reveal novel insights into the pathobiology of treatment failure and suggest CSF1R as a drug target of at-risk CHL.

Tumor-associated macrophages predict inferior outcomes in classic Hodgkin lymphoma: a correlative study from the E2496 Intergroup trial

Increased tumor-associated macrophages (TAMs) are reported to be associated with poor prognosis in classic Hodgkin lymphoma (CHL). We investigated the prognostic significance of TAMs in the E2496 Intergroup trial, a multicenter phase 3 randomized controlled trial comparing ABVD and Stanford V chemotherapy in locally extensive and advanced stage CHL. Tissue microarrays were constructed from formalin-fixed, paraffin-embedded tumor tissue and included 287 patients. Patients were randomly assigned into training (n = 143) and validation (n = 144) cohorts. Immunohistochemistry for CD68 and CD163, and in situ hybridization for EBV-encoded RNA were performed. CD68 and CD163 IHC were analyzed by computer image analysis; optimum thresholds for overall survival (OS) were determined in the training cohort and tested in the independent validation cohort. Increased CD68 and CD163 expression was significantly associated with inferior failure-free survival and OS in the validation cohort. Increased CD68 and CD163 expression was associated with increased age, EBV-encoded RNA positivity, and mixed cellularity subtype of CHL. Multivariate analysis in the validation cohort showed increased CD68 or CD163 expression to be significant independent predictors of inferior failure-free survival and OS. We demonstrate the prognostic significance of TAMs in locally extensive and advanced-stage CHL in a multicenter phase 3 randomized controlled clinical trial.

Tumor-associated macrophages in pediatric classical Hodgkin lymphoma: association with Epstein-Barr virus, lymphocyte subsets, and prognostic impact

PURPOSE

Tumor-infiltrating macrophages are associated with adverse outcome in adult classical Hodgkin lymphoma (cHL). We have previously shown age-related changes in the lymphocyte composition of pediatric cHL. We therefore hypothesized that the number, function, and prognostic impact of macrophages in pediatric cHL would be different from adult cases.

EXPERIMENTAL DESIGN

We analyzed the number of macrophages and dendritic cells (DC) in the tumor microenvironment of pediatric cHL by immunohistochemistry. Results were analyzed in context of age, histologic characteristics, Epstein-Barr virus (EBV) status, clinical follow-up, and our previous study of T-cell populations in these cases.

RESULTS

One hundred cHL cases were studied, including 69% nodular sclerosis and 23% mixed cellularity cases. A total of 44.8% of cases were EBV-positive. Patients ≤10 years displayed more CD14(+) cells (P = 0.025). In comparison with nodular sclerosis, mixed cellularity was characterized by higher numbers of CD14(+), (P = 0.003) and CD163(+) cells (P = 0.027). EBV(+) cases exhibited higher numbers of CD14(+) (P < 0.0005), CD68(+) (P = 0.005), and CD163(+) cells (P = 0.02). CD68-positive cells did not display an effect on outcome. Worse overall survival was observed in cases with CD163/CD8 ratio ≥2 (P = 0.007). High numbers of CD163(+) cells were associated with worse progression-free survival (PFS; P = 0.015). Furthermore, high numbers of CD163(+) and granzyme B(+) cells were associated with worse PFS in EBV-negative (P = 0.005) but not in EBV-positive cases.

CONCLUSION

Our results suggest that macrophage composition in pediatric cHL is distinct from adults. Functional status of macrophages and their value as prognostic indicators in pediatric cHL may depend on EBV status.

The ratio of the absolute lymphocyte count to the absolute monocyte count is associated with prognosis in Hodgkin's lymphoma: correlation with tumor-associated macrophages

BACKGROUND

Although most patients with classical Hodgkin's lymphoma (cHL) have a long survival duration, the current risk stratification is imperfect. A recent study suggested a prognostic role for the peripheral blood absolute lymphocyte count/absolute monocyte count (ALC/AMC) ratio at diagnosis in cHL. It is intriguing to investigate the significance of the ALC/AMC ratio in relation to tumor-associated macrophages (TAMs), yet another prognostic factor for cHL.

METHODS

We examined the prognostic impact of the ALC, AMC, and ALC/AMC ratio in 312 cHL patients (median age, 37 years) using receiver operating characteristic curve analysis for optimal cutoff values, and compared these with TAM content.

RESULTS

The median follow-up was 65 months (range, 0.1-245 months). On univariate analysis, a low ALC/AMC ratio (<2.9) was correlated with a poorer overall survival (OS) outcome. A subgroup analysis of patients with limited-stage disease showed that the ALC/AMC ratio was significantly correlated with the OS time. Multivariate analysis showed the ALC/AMC ratio to be an independent prognostic factor for OS outcome. A Spearman correlation test of TAM content showed a negative correlation with the ALC/AMC ratio and a positive correlation with the peripheral blood macrophage percentage.

CONCLUSIONS

This study suggests that the ALC/AMC ratio may be a simple, inexpensive, and independent prognostic factor for OS outcome in patients with cHL and may have a role in the stratification of cHL patients in addition to the International Prognostic Score and TAM content.

Immunohistochemical markers for tumor associated macrophages and survival in advanced classical Hodgkin's lymphoma

A subset of patients with advanced classical Hodgkin's lymphoma is refractory to standard therapies. Therefore, it is relevant to identify new biologically-based prognostic markers. Recently, tumor associated macrophages have been proposed as a factor that predicts survival, although contradictory results have also been reported. Here we analyzed four macrophage markers (CD68, CD163, LYZ, and STAT1) using immunohistochemistry and automated quantification, in two independent series of advanced classical Hodgkin's lymphoma (n=266 and 103 patients, respectively). Our results did not confirm that specific macrophage immunohistochemical markers could be used as surrogates for gene expression profiling studies. Survival analyses did not show correlation between CD163, LYZ or STAT1 and either failure-free or disease-specific survival. There was an association between CD68 and disease-specific survival, but it was not consistent in both series. In conclusion, individual tumor associated macrophage markers cannot be used to predict outcome before technical standardization and prospective validation in independent series of patients with comparable stages and treatments.

Identification and manipulation of tumor associated macrophages in human cancers

Evading immune destruction and tumor promoting inflammation are important hallmarks in the development of cancer. Macrophages are present in most human tumors and are often associated with bad prognosis. Tumor associated macrophages come in many functional flavors ranging from what is known as classically activated macrophages (M1) associated with acute inflammation and T-cell immunity to immune suppressive macrophages (M2) associated with the promotion of tumor growth. The role of these functionally different myeloid cells is extensively studied in mice tumor models but dissimilarities in markers and receptors make the direct translation to human cancer difficult. This review focuses on recent reports discriminating the type of infiltrating macrophages in human tumors and the environmental cues present that steer their differentiation. Finally, immunotherapeutic approaches to interfere in this process are discussed.