Revisiting the immune microenvironment of diffuse large B-cell lymphoma using a tissue microarray and immunohistochemistry: robust semi-automated analysis reveals CD3 and FoxP3 as potential predictors of response to R-CHOP.

Gene expression studies have identified the microenvironment as a prognostic player in diffuse large B-cell lymphoma. However, there is a lack of simple immune biomarkers that can be applied in the clinical setting and could be helpful in stratifying patients. Immunohistochemistry has been used for this purpose but the results are inconsistent. We decided to reinvestigate the immune microenvironment and its impact using immunohistochemistry, with two systems of image analysis, in a large set of patients with diffuse large B-cell lymphoma. Diagnostic tissue from 309 patients was arrayed onto tissue microarrays. Results from 161 chemoimmunotherapy-treated patients were used for outcome prediction. Positive cells, percentage stained area and numbers of pixels/area were quantified and results were compared with the purpose of inferring consistency between the two semi-automated systems. Measurement cutpoints were assessed using a recursive partitioning algorithm classifying results according to survival. Kaplan-Meier estimators and Fisher exact tests were evaluated to check for significant differences between measurement classes, and for dependence between pairs of measurements, respectively. Results were validated by multivariate analysis incorporating the International Prognostic Index. The concordance between the two systems of image analysis was surprisingly high, supporting their applicability for immunohistochemistry studies. Patients with a high density of CD3 and FoxP3 by both methods had a better outcome. Automated analysis should be the preferred method for immunohistochemistry studies. Following the use of two methods of semi-automated analysis we suggest that CD3 and FoxP3 play a role in predicting response to chemoimmunotherapy in diffuse large B-cell lymphoma.

What determines therapeutic choices for elderly patients with DLBCL? Clinical findings of a multicenter study in Portugal.

BACKGROUND: Age is a negative prognostic factor in lymphomas, and elderly patients are often undertreated because of toxicity concerns. The pattern of treatment in elderly patients with diffuse large B-cell lymphoma (DLBCL) in Portugal has not been previously described. PATIENTS AND METHODS: We conducted a multicenter retrospective study including 378 elderly patients with DLBCL receiving alkylating agent-containing regimens between 2003 and 2010. We compared the outcome of patients aged 60 to 79 years with patients > 79 years and analyzed the second group according to treatment. RESULTS: R-CHOP (rituximab, cyclophosphamide, doxorubicin [hydroxydaunorubicin], vincristine [Oncovin], prednisolone) was prescribed in only 60% of patients and was prescribed significantly less in patients > 79 years, despite no significant differences being found in comorbidities between the 2 age groups. Similarly, dose reductions frequently were instituted because of chronologic age and not always because of toxicity. When different regimens were compared, multivariate analysis showed an independent beneficial effect of R-CHOP in treatment outcomes. Additionally, treatment with anthracyclines and rituximab predicted a better progression-free survival (PFS) and time to progression (TTP) in patients > 79 years. CONCLUSION: This was the first characterization of the clinical care of elderly Portuguese patients with DLBCL. We showed that R-CHOP is effective even in patients > 79 years, emphasizing that treatment decisions based on age alone can compromise treatment efficacy and outcome in fit patients.

Poor concordance among nine immunohistochemistry classifiers of cell-of-origin for diffuse large B-cell lymphoma: implications for therapeutic strategies.

PURPOSE: The opportunity to improve therapeutic choices on the basis of molecular features of the tumor cells is on the horizon in diffuse large B-cell lymphoma (DLBCL). Agents such as bortezomib exhibit selective activity against the poor outcome activated B-cell type (ABC) DLBCL. In order for targeted therapies to succeed in this disease, robust strategies that segregate patients into molecular groups with high reliability are needed. Although molecular studies are considered gold standard, several immunohistochemistry (IHC) algorithms have been published that claim to be able to stratify patients according to their cell-of-origin and to be relevant for patient outcome. However, results are poorly reproducible by independent groups. EXPERIMENTAL DESIGN: We investigated nine IHC algorithms for molecular classification in a dataset of DLBCL diagnostic biopsies, incorporating immunostaining for CD10, BCL6, BCL2, MUM1, FOXP1, GCET1, and LMO2. IHC profiles were assessed and agreed among three expert observers. A consensus matrix based on all scoring combinations and the number of subjects for each combination allowed us to assess reliability. The survival impact of individual markers and classifiers was evaluated using Kaplan-Meier curves and the log-rank test. RESULTS: The concordance in patient's classification across the different algorithms was low. Only 4% of the tumors have been classified as germinal center B-cell type (GCB) and 21% as ABC/non-GCB by all methods. None of the algorithms provided prognostic information in the R-CHOP (rituximab plus cyclophosphamide-adriamycin-vincristine-prednisone)-treated cohort. CONCLUSION: Further work is required to standardize IHC algorithms for DLBCL cell-of-origin classification for these to be considered reliable alternatives to molecular-based methods to be used for clinical decisions.