John Raemaekers

Immunohistochemical Prognostic Markers in Diffuse Large B-Cell Lymphoma: Validation of Tissue Microarray As a Prerequisite for Broad Clinical Applications—A Study From the Lunenburg Lymphoma Biomarker Consortium

PURPOSE The results of immunohistochemical class prediction and prognostic stratification of diffuse large B-cell lymphoma (DLBCL) have been remarkably various thus far. Apart from biologic variations, this may be caused by differences in laboratory techniques, scoring definitions, and inter- and intraobserver variations. In this study, an international collaboration of clinical lymphoma research groups from Europe, United States, and Canada concentrated on validation and standardization of immunohistochemistry of the currently potentially interesting prognostic markers in DLBCL. PATIENTS AND METHODS Sections of a tissue microarray from 36 patients with DLBCL were stained in eight laboratories with antibodies to CD20, CD5, bcl-2, bcl-6, CD10, HLA-DR, MUM1, and MIB-1 according to local methods. The study was performed in two rounds firstly focused on the evaluation of laboratory staining variation and secondly on the scoring variation. RESULTS Different laboratory staining techniques resulted in unexpectedly highly variable results and very poor reproducibility in scoring for almost all markers. No single laboratory stood out as uniformly poor or excellent. With elimination of variation due to staining, high agreement was found for CD20, HLA-DR, and CD10. Poor agreement was found for bcl-6 and Ki-67. Optimization of techniques and uniformly agreed on scoring criteria improved reproducibility. CONCLUSION This study shows that semiquantitative immunohistochemistry for subclassification of DLBCL is feasible and reproducible, but exhibits varying rates of concordance for different markers. These findings may explain the wide variation of biomarker prognostic impact reported in the literature. Harmonization of techniques and centralized consensus review appears mandatory when using immunohistochemical biomarkers for treatment stratification.

A novel method to compensate for different amplification efficiencies between patient DNA samples in quantitative real-time PCR.

Quantification of residual disease by real-time polymerase chain reaction (PCR) will become a pivotal tool in the development of patient-directed therapy. In recent years, various protocols to quantify minimal residual disease in leukemia or lymphoma patients have been developed. These assays assume that PCR efficiencies are equal for all samples. Determining t(14;18) and albumin reaction efficiencies for sixteen follicular lymphoma patient samples revealed higher efficiencies for blood samples than for lymph node samples in general. However, within one sample both reactions had equivalent efficiencies. Differences in amplification efficiencies between patient samples (low efficiencies) and the calibrator in quantitative analyses result in the underestimation of residual disease in patient samples whereby the weakest positive patient samples are at highest error. Based on these findings for patient samples, the efficiency compensation control was developed. This control includes two reference reactions in a multiplex setting, specific for the beta-actin and albumin housekeeping genes that are present in a constant ratio within DNA templates. The difference in threshold cycle values for both reference reactions, ie, the Ct(2) value, is dependent on the amplification efficiency, and is used to compensate for efficiency differences between patient samples and the calibrator. The beta-actin reference reaction is also used to normalize for DNA input. Furthermore, the efficiency compensation control facilitates identification of patient samples that are so contaminated with PCR inhibitory compounds that different amplification reactions are affected to a different extent. Accurate quantitation of residual disease in these samples is therefore impossible with the current quantitative real-time PCR protocols. Identification and exclusion of these inadequate samples will be of utmost importance in quantitative retrospective studies, but even more so, in future molecular diagnostic analyses.

Comparison of CHOP chemotherapy with autologous bone marrow transplantation for slowly responding patients with aggressive non-Hodgkin's lymphoma

BACKGROUND High-dose chemoradiotherapy combined with autologous bone marrow transplantation can cure patients with disseminated, aggressive non-Hodgkins lymphoma in whom first-line chemotherapy has failed. In contrast, cure is rare with second-line chemotherapy. It has been suggested that patients with slow responses to the initial phase of first-line chemotherapy are at high risk for relapse. Therefore, such patients are potential candidates for early bone marrow transplantation. METHODS To investigate whether patients with slow responses, defined as only a partial response after three courses of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), would benefit from early transplantation, we conducted a prospective, randomized trial. The early application of high-dose chemoradiotherapy and autologous bone marrow transplantation was compared with the continuation of CHOP therapy for another five courses. Patients with complete responses after three courses of CHOP (fast responses) and patients who responded partially but still had tumor-positive marrow continued with another five courses of CHOP. The study end points were the response rate, overall survival, disease-free survival, and event-free survival. RESULTS Of 286 patients who could be evaluated for the rapidity of their response after three courses of CHOP, 38 percent had fast responses, 47 percent had slow responses, and 15 percent had no response. Among 106 patients with slow responses who had lymphoma-negative marrow, 69 patients (65 percent) were randomized. Seventy-four percent of the CHOP group and 68 percent of the transplantation group had complete remissions (P = 0.54). At four years the rates of overall, disease-free, and event-free survival were 85, 72, and 53 percent, respectively, in the CHOP group and 56, 60, and 41 percent in the transplantation group (P > 0.10). The disease-free survival in both groups did not differ significantly from that of nonrandomized patients with fast responses (54 percent at four years). CONCLUSIONS The early application of high-dose, marrow-ablative chemoradiotherapy with autologous bone marrow transplantation does not improve the outcome in patients with aggressive non-Hodgkins lymphoma that responds slowly to first-line CHOP chemotherapy.

Omitting Radiotherapy in Early Positron Emission Tomography–Negative Stage I/II Hodgkin Lymphoma Is Associated With an Increased Risk of Early Relapse: Clinical Results of the Preplanned Interim Analysis of the Randomized EORTC/LYSA/FIL H10 Trial

PURPOSE Combined-modality treatment is standard treatment for patients with clinical stage I/II Hodgkin lymphoma (HL). We hypothesized that an early positron emission tomography (PET) scan could be used to adapt treatment. Therefore, we started the randomized EORTC/LYSA/FIL Intergroup H10 trial evaluating whether involved-node radiotherapy (IN-RT) could be omitted without compromising progression-free survival in patients attaining a negative early PET scan after two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) as compared with standard combined-modality treatment. PATIENTS AND METHODS Patients age 15 to 70 years with untreated clinical stage I/II HL were eligible. Here we report the clinical outcome of the preplanned interim futility analysis scheduled to occur after documentation of 34 events in the early PET-negative group. Because testing for futility in this noninferiority trial corresponds to testing the hypothesis of no difference, a one-sided superiority test was conducted. RESULTS The analysis included 1,137 patients. In the favorable subgroup, 85.8% had a negative early PET scan (standard arm, one event v experimental arm, nine events). In the unfavorable subgroup, 74.8% had a negative early PET scan (standard arm, seven events v experimental arm, 16 events). The independent data monitoring committee concluded it was unlikely that we would show noninferiority in the final results for the experimental arm and advised stopping random assignment for early PET-negative patients. CONCLUSION On the basis of this analysis, combined-modality treatment resulted in fewer early progressions in clinical stage I/II HL, although early outcome was excellent in both arms. The final analysis will reveal whether this finding is maintained over time.

Gene-Expression and Immunohistochemical Study of Specific T-Cell Subsets and Accessory Cell Types in the Transformation and Prognosis of Follicular Lymphoma

PURPOSE Despite the generally favorable clinical course in follicular lymphoma (FL), a minority of patients have a poor prognosis-with death within 3 years of diagnosis-most often due to transformation to aggressive disease. PATIENTS AND METHODS In this study, we analyzed the potential of predicting early transformation on the basis of gene expression and immunologic parameters in FL biopsy samples taken at diagnosis. RESULTS At the gene-expression level, FL is a highly uniform disease at the time of diagnosis, precluding the detection of sufficiently validated prognostic gene-expression profiles suitable for a clinical setting. Combinations of differentially expressed genes indicate that immunologic mechanisms play a differential role in the risk of early transformation. Using immunohistochemistry for specific cell populations, the spatial distribution to neoplastic follicles and the activation of CD4-positive T-helper cells (P = .002) and specifically T-helper 1 (P = .004) were shown to be highly discriminatory to predict early transformation. A role for functional modulation of follicular dendritic cells could also be supported (P = .04). Other cell populations, including CD68-positive macrophages and regulatory T cells, were not differentially present. CONCLUSION These results support the identification of FL as an immunologically functional disease in which an interaction of the tumor cells and the functional composition of the microenvironment determines the clinical behavior.

Combined-Modality Therapy for Clinical Stage I or II Hodgkin's Lymphoma: Long-Term Results of the European Organisation for Research and Treatment of Cancer H7 Randomized Controlled Trials

PURPOSE In early-stage Hodgkins lymphoma (HL), subtotal nodal irradiation (STNI) and combined chemotherapy/radiotherapy produce high disease control rates but also considerable late toxicity. The aim of this study was to reduce this toxicity using a combination of low-intensity chemotherapy and involved-field radiotherapy (IF-RT) without jeopardizing disease control. PATIENTS AND METHODS Patients with stage I or II HL were stratified into two groups, favorable and unfavorable, based on the following four prognostic factors: age, symptoms, number of involved areas, and mediastinal-thoracic ratio. The experimental therapy consisted of six cycles of epirubicin, bleomycin, vinblastine, and prednisone (EBVP) followed by IF-RT. It was randomly compared, in favorable patients, to STNI and, in unfavorable patients, to six cycles of mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, and vinblastine (MOPP/ABV hybrid) and IF-RT. RESULTS Median follow-up time of the 722 patients included was 9 years. In 333 favorable patients, the 10-year event-free survival rates (EFS) were 88% in the EBVP arm and 78% in the STNI arm (P = .0113), with similar 10-year overall survival (OS) rates (92% v 92%, respectively; P = .79). In 389 unfavorable patients, the 10-year EFS rate was 88% in the MOPP/ABV arm compared with 68% in the EBVP arm (P < .001), leading to 10-year OS rates of 87% and 79%, respectively (P = .0175). CONCLUSION A treatment strategy for early-stage HL based on prognostic factors leads to high OS rates in both favorable and unfavorable patients. In favorable patients, the combination of EBVP and IF-RT can replace STNI as standard treatment. In unfavorable patients, EBVP is significantly less efficient than MOPP/ABV.

Second Cancer Risk Up to 40 Years after Treatment for Hodgkin’s Lymphoma

BACKGROUND Survivors of Hodgkins lymphoma are at increased risk for treatment-related subsequent malignant neoplasms. The effect of less toxic treatments, introduced in the late 1980s, on the long-term risk of a second cancer remains unknown. METHODS We enrolled 3905 persons in the Netherlands who had survived for at least 5 years after the initiation of treatment for Hodgkins lymphoma. Patients had received treatment between 1965 and 2000, when they were 15 to 50 years of age. We compared the risk of a second cancer among these patients with the risk that was expected on the basis of cancer incidence in the general population. Treatment-specific risks were compared within the cohort. RESULTS With a median follow-up of 19.1 years, 1055 second cancers were diagnosed in 908 patients, resulting in a standardized incidence ratio (SIR) of 4.6 (95% confidence interval [CI], 4.3 to 4.9) in the study cohort as compared with the general population. The risk was still elevated 35 years or more after treatment (SIR, 3.9; 95% CI, 2.8 to 5.4), and the cumulative incidence of a second cancer in the study cohort at 40 years was 48.5% (95% CI, 45.4 to 51.5). The cumulative incidence of second solid cancers did not differ according to study period (1965-1976, 1977-1988, or 1989-2000) (P=0.71 for heterogeneity). Although the risk of breast cancer was lower among patients who were treated with supradiaphragmatic-field radiotherapy not including the axilla than among those who were exposed to mantle-field irradiation (hazard ratio, 0.37; 95% CI, 0.19 to 0.72), the risk of breast cancer was not lower among patients treated in the 1989-2000 study period than among those treated in the two earlier periods. A cumulative procarbazine dose of 4.3 g or more per square meter of body-surface area (which has been associated with premature menopause) was associated with a significantly lower risk of breast cancer (hazard ratio for the comparison with no chemotherapy, 0.57; 95% CI, 0.39 to 0.84) but a higher risk of gastrointestinal cancer (hazard ratio, 2.70; 95% CI, 1.69 to 4.30). CONCLUSIONS The risk of second solid cancers did not appear to be lower among patients treated in the most recent calendar period studied (1989-2000) than among those treated in earlier periods. The awareness of an increased risk of second cancer remains crucial for survivors of Hodgkins lymphoma. (Funded by the Dutch Cancer Society.).

Prognostic significance of immunohistochemical biomarkers in diffuse large B-cell lymphoma: a study from the Lunenburg Lymphoma Biomarker Consortium

The Lunenburg Lymphoma Biomarker Consortium (LLBC) evaluated the prognostic value of IHC biomarkers in a large series of patients with diffuse large B-cell lymphoma (DLBCL). Clinical data and tumor samples were retrieved from 12 studies from Europe and North America, with patients treated before or after the rituximab era. Using tissue microarrays from 1514 patients, IHC for BCL2, BCL6, CD5, CD10, MUM1, Ki67, and HLA-DR was performed and scored according to previously validated protocols. Optimal cut points predicting overall survival of patients treated in the rituximab era could only be determined for CD5 (P = .003) and Ki67 (P = .02), whereas such cut points for BCL2, BCL6, HLA-DR, and MUM1 could only be defined in patients not receiving rituximab. A prognostic model for patients treated in the rituximab era identified 4 risk groups using BCL2, Ki67, and International Prognostic Index (IPI) with improved discrimination of low-risk patients. Newly recognized correlations between specific biomarkers and IPI highlight the importance of carefully controlling for clinical and biologic factors in prognostic models. These data demonstrate that the IPI remains the best available index in patients with DLBCL treated with rituximab and chemotherapy.

Impact of the tumor microenvironment on prognosis in follicular lymphoma is dependent on specific treatment protocols

The clinical behavior of follicular lymphoma is largely determined by properties of the non-malignant tumor microenvironment. The results of this study suggest that characteristic properties of the microenvironment in follicular lymphoma influence the response to treatment. See related perspective article on page 16. Background The clinical behavior of follicular lymphoma is largely determined by properties of the non-malignant tumor microenvironment. The precise nature of the cell populations is still unclear and published data on their prognostic significance are highly conflicting. This may be partly due to heterogeneous composition and treatments. Design and Methods Pre-treatment biopsy samples of patients with follicular lymphoma treated in an EORTC/BNLI trial comparing fludarabine to cyclophosphamide, vincristine and prednisone (CVP) chemotherapy could be retrieved for 61 patients in five European countries. Immunohistochemical investigations were performed evaluate tumor cell characteristics, T-cell subsets, follicular dendritic cells and macrophages and associations with clinical outcome were studied. Results Some markers showed a homogeneous prognostic impact, while others had a different nd sometimes opposite effect in the treatment arms. CD69 expression on tumor cells was a poor prognostic sign and an interfollicular infiltrate of FoxP3-positive T cells was a good prognostic sign irrespective of the treatment arm. It is suggestive that a dense infiltrate of FoxP3-positive T cells, dense and interfollicular infiltrate of CD68-positive macrophages and complete follicular dendritic meshworks were associated with a favorable time to progression in CVP-treated patients, while being poor prognostic sign in fludarabine-treated patients. Conclusions Our results suggest that characteristic properties of the microenvironment in follicular lymphoma determines the responses to essentially different chemotherapeutic approaches. These data may provide an explanation for the highly conflicting results on immunohistochemical markers and the prognostic role of the microenvironment in follicular lymphoma reported thus far and lay the basis for the development of predictive assays to tailor treatment in patients with follicular lymphoma.

Cardiovascular Disease After Hodgkin Lymphoma Treatment: 40-Year Disease Risk

IMPORTANCE Hodgkin lymphoma (HL) survivors are at increased risk of cardiovascular diseases. It is unclear, however, how long the increased risk persists and what the risk factors are for various cardiovascular diseases. OBJECTIVES To examine relative and absolute excess risk up to 40 years since HL treatment compared with cardiovascular disease incidence in the general population and to study treatment-related risk factors for different cardiovascular diseases. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study included 2524 Dutch patients diagnosed as having HL at younger than 51 years (median age, 27.3 years) who had been treated from January 1, 1965, through December 31, 1995, and had survived for 5 years since their diagnosis. EXPOSURES Treatment for HL, including prescribed mediastinal radiotherapy dose and anthracycline dose. MAIN OUTCOMES AND MEASURES Data were collected from medical records and general practitioners. Cardiovascular events, including coronary heart disease (CHD), valvular heart disease (VHD), and cardiomyopathy and congestive heart failure (HF), were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. RESULTS After a median follow-up of 20 years, we identified 1713 cardiovascular events in 797 patients. After 35 years or more, patients still had a 4- to 6-fold increased standardized incidence ratio of CHD or HF compared with the general population, corresponding to 857 excess events per 10,000 person-years. Highest relative risks were seen in patients treated before 25 years of age, but substantial absolute excess risks were also observed for patients treated at older ages. Within the cohort, the 40-year cumulative incidence of cardiovascular diseases was 50% (95% CI, 47%-52%). Fifty-one percent of patients with a cardiovascular disease developed multiple events. For patients treated before 25 years of age, cumulative incidences at 60 years or older were 20%, 31%, and 11% for CHD, VHD, and HF as first events, respectively. Mediastinal radiotherapy increased the risks of CHD (hazard ratio [HR], 2.7; 95% CI, 2.0-3.7), VHD (HR, 6.6; 95% CI, 4.0-10.8), and HF (HR, 2.7; 95% CI, 1.6-4.8), and anthracycline-containing chemotherapy increased the risks of VHD (HR, 1.5; 95% CI, 1.1-2.1) and HF (HR, 3.0; 95% CI, 1.9-4.7) as first events compared with patients not treated with mediastinal radiotherapy or anthracyclines, respectively. Joint effects of mediastinal radiotherapy, anthracyclines, and smoking appeared to be additive. CONCLUSIONS AND RELEVANCE Throughout their lives, HL survivors treated at adolescence or adulthood are at high risk for various cardiovascular diseases. Physicians and patients should be aware of this persistently increased risk.