Prognostic Factors In Follicular Lymphoma Research Articles

BIOM-09. CLINICAL EFFECT OF CD25 ON THE MTX-BASED CHEMOSENSITIVITY OF PRIMARY CENTRAL NERVUS SYSTEM LYMPHOMA

Abstract INTRODUCTION Primary central nervous system diffuse large B-cell lymphoma (PCNSL) is treated with chemotherapy, mainly with high-dose methotrexate (HD-MTX), but some cases are resistant to treatment and relapse in a short period. However, a biomarker that predicts the chemosensitivity and recurrence has not yet been identified. In this study, we used surface marker analysis of tumor tissue using flow cytometry to search for biomarkers related to chemosensitivity and early recurrence. METHODS From 2017 to 2023, 25 patients were diagnosed with PCNSL by biopsy in Kobe University Hospital, and flow cytometry of the biopsy tissues were performed. Cerebrospinal fluid (CSF) examination including sIL2R, β2MG, and IL-10 was performed in all cases before surgery, and treatment based on methotrexate was administered postoperatively. We retrospectively analyzed patient characteristics, flow cytometry data, treatment details, response rate, time to recurrence, and overall survival. RESULTS The mean age of the patients was 71 (range, 37-80) years. In univariate analysis, high expression level of CD25 (interleukin-2 receptor, IL-2R) in the tissue was associated with a lower response rate to MTX-based chemotherapy (Fisher’s exact test, p=0.0072) and had a tendency of shorter time to recurrence. However, there were no significant differences in progression-free survival and overall survival. There was no correlation between expression level of CD25 in tissue and sIL-2R in CSF. Expression level of sIL-2R in CSF was independent of CD25 expression in tissue. CONCLUSION There are some reports that CD25 can be a prognostic factor in follicular lymphoma, but no reports in PCNSL. Here, we suggested that high expression level of CD25 in PCNSL tissue was associated to chemoresistance and early recurrence. In cases of PCNSL with high CD25 expression level, additional whole-brain irradiation and transition to tirabrutinib be considered because there are possibilities of chemoresistance and early recurrence.

Small sized centroblasts as poor prognostic factor in follicular lymphoma - Based on artificial intelligence analysis

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists.We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The ‘excellent prognosis’ group were without recurrence or progression of follicular lymphoma within 60 months, the ‘poor prognosis’ group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the ‘indeterminate prognosis’ group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 μm2 had poorer event-free survival than those with a mean nuclear area of ≥55 μm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

Prognostic value of the combination of volume, massiveness and fragmentation parameters measured on baseline FDG pet in high-burden follicular lymphoma

The prognostic value of radiomic quantitative features measured on pre-treatment 18F-FDG PET/CT was investigated in patients with follicular lymphoma (FL). We conducted a retrospective study of 126 FL patients (grade 1-3a) diagnosed between 2006 and 2020. A dozen of PET/CT-derived features were extracted via a software (Oncometer3D) from baseline 18F-FDG PET/CT images. The receiver operating characteristic (ROC) curve, Kaplan–Meier method and Cox analysis were used to assess the prognostic factors for progression of disease within 24 months (POD24) and progression-free survival at 24 months. Four different clusters were identified among the twelve PET parameters analyzed: activity, tumor burden, fragmentation-massiveness and dispersion. On ROC analyses, TMTV, the total metabolic tumor volume, had the highest AUC (0.734) followed by medPCD, the median distance between the centroid of the tumors and their periphery (AUC: 0.733). Patients with high TMTV (HR = 4.341; p < 0.001), high Tumor Volume Surface Ratio (TVSR) (HR = 3.204; p < 0.003) and high medPCD (HR = 4.507; p < 0.001) had significantly worse prognosis in both Kaplan–Meier and Cox univariate analyses. Furthermore, a synergistic effect was observed in Kaplan–Meier and Cox analyses combining these three PET/CT-derived parameters (HR = 12.562; p < 0.001). Having two or three high parameters among TMTV, TVSR and medPCD was able to predict POD24 status with a specificity of 68% and a sensitivity of 75%. TMTV, TVSR and baseline medPCD are strong prognostic factors in FL and their combination better predicts disease prognosis.

Discovery and Validation of a Simplified Scoring System (the PRIMA-Prognostic Index) in De Novo Follicular Lymphoma Treated Initially with Immunochemotherapy

Introduction. In follicular lymphoma (FL), no prognostic index has been built based on a cohort of patients treated only with initial immunochemotherapy. Given the emergence of new biomolecular and metabolic prognostic factors in FL, an easy-to-compute and reliable scoring system utilizing such variables could aid in trial stratification and routine clinical evaluation. Methods. The primary endpoint for model building was progression-free survival (PFS). For discovery, we used the large prospective PRIMA trial cohort of 1,135 patients treated with initial R-chemotherapy +/- R-maintenance. Variables considered for model building included age, sex, performance status, B symptoms, stage, number of nodal and extranodal sites involved, LDH, hemoglobin, longest diameter of the largest lymph node, presence of effusion and compression syndrome, circulating lymphoma cells, platelet count, serum albumin, bone marrow involvement, and s2m. For validation, we combined 175 patients with high tumor burden FL from the R-CHVP+interferon arm of treatment from the FL2000 trial and 304 patients prospectively enrolled in the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE) who were treated upfront with immunochemotherapy. Event-free survival (EFS) was the endpoint available in the validation cohort. For model building, we used a two-step approach based on resample Cox regression and conditional inference trees analyses to identify 3 patient groups of approximately equal size and experiencing differential outcome in terms of PFS. For comparison with the FLIPI, model9s discrimination was computed using theConcordance Probability Estimates (CPE) based upon Harrell9s c-index. All statistical tests were 2-sided. A P value Results. The final simplified score based on the discovery set was called the PRIMA-PI (PRIMA-prognostic index) and comprised 3 risk categories: high (s2m > 3 mg/L), low (s2m ≤ 3 mg/L without bone marrow involvement) and intermediate (≤ 3 mg/L with bone marrow involvement). In the discovery cohort, the PRIMA-PI was highly discriminatory with 5-year PFS of 69% (95%CI: 64-73%), 55% (49-60%) and 37% (32-42%) in the low-, intermediate- and high-risk groups respectively (P In the validation cohort, the PRIMA-PI remained highly discriminatory: 5-year EFS was 77% (69-83%), 57% (48-66%) and 44% (35-52%) in the low-, intermediate- and high-risk groups respectively (P Conclusion. We developed and validated a new prognostic tool comprising only 2 parameters (bone marrow involvement and s2m) which are easily measured clinically. The PRIMA-PI is a new and easy-to-compute prognostic index for patients treated upfront with immunochemotherapy. This could serve as a basis for building more sophisticated and integrated biomolecular scores. Disclosures Bachy: Amgen: Honoraria; Sandoz: Consultancy, Honoraria; Mundipharma: Research Funding; Roche/Genentech: Consultancy, Honoraria, Research Funding. Estell: Janssen: Membership on an entity9s Board of Directors or advisory committees. Delmer: Abbvie: Consultancy, Honoraria; Janssen: Honoraria; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Belada: Roche: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel grants , Research Funding, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel grants , Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel grants , Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau. Ansell: Celldex: Research Funding; Seattle Genetics: Research Funding; Bristol-Myers Squibb: Research Funding; Merck: Research Funding; Affimed: Research Funding. Lamy: Roche: Consultancy, Honoraria. Cerhan: Janssen: Other: Scientific Advisory Board (REMICADELYM4001); Janssen: Other: Multiple Myeloma Registry Steering . Salles: Gilead: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Servier: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding; MSD: Consultancy, Honoraria; Kite: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Morphosys: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees.

Good prognosis for follicular lymphoma with estrogen receptor α-positive follicular dendritic cells.

Follicular lymphoma (FL) has a meshwork of follicular dendritic cells (FDCs). We previously demonstrated the presence of estrogen receptor alpha (ERα)+CD23+ FDCs in grades 1‐2 FL. The significance of FDCs as a prognostic factor in FL remains unknown. The current study aimed to compare clinicopathological features, including prognosis, between FL with and without ERα+ FDCs. This study evaluated the clinicopathological significance of ERα expression in 70 FL patients by immunostaining. The presence of ERα mRNA on FDCs from 5 FL patients was confirmed by CD21/ERα double staining (immunohistochemistry and in situ hybridization). We defined patients with frequent ERα expression as the ERαhigh group and those with infrequent ERα expression as the ERαlow group. Thirty‐two patients were assigned to the ERαhigh group (45.7%), and 38 patients were assigned to the ERαlow group (54.3%). Both overall survival (OS) and progression‐free survival (PFS) were significantly better in the ERαhigh group than in the ERαlow group (OS, log‐rank, P = .0465; PFS, log‐rank, P = .0336). Moreover, high ERα expression on FDCs was an independent prognostic factor for OS in both the univariate ([hazard ratio] HR, 0.163; P = .0260) and multivariate (HR, 0.050; P = .0188) analyses and for PFS in both the univariate (HR, 0.232; P = .0213) and multivariate (HR, 0.084; P = .0243) analyses. ERα mRNA expression was detected in CD21+ FDCs within the neoplastic follicles of FL patients. In conclusion, a neoplastic follicular microenvironment with ERα‐positive FDCs might affect the grade and presence of the follicular pattern of FL and improve patient prognosis.

Indolent Lymphoma and Vitamin D (ILyAD): A Double-Blind, Randomized, Placebo-Controlled Trial to Evaluate the Supplemental Effect of Vitamin D on Event-Free Survival in Patients with Low Tumor Burden Indolent Non-Hodgkin Lymphoma Treated with Rituximab

Indolent Lymphoma and Vitamin D (ILyAD): A Double-Blind, Randomized, Placebo-Controlled Trial to Evaluate the Supplemental Effect of Vitamin D on Event-Free Survival in Patients with Low Tumor Burden Indolent Non-Hodgkin Lymphoma Treated with Rituximab

New Treatment Options in Advanced Stage Follicular Lymphoma.

Follicular lymphoma is one of the most common non-Hodgkin's lymphomas with an expected survival of more than 20 years for the majority of patients. This impressive outcome has been achieved with the introduction of immunochemotherapy, as first line treatment with remissions lasting over 8 years, followed by other treatment options at first or subsequent relapse. However, certain groups of patients still have a poor prognosis. In recent years the efficacy of chemotherapy regimens has been augmented by new compounds selectively targeting the cell surface, intracellular pathways, and/or the microenvironment. Some of these are beginning to change the therapeutic landscape. This review summarizes prognostic factors in follicular lymphoma in order to identify patients with greatest medical need for these new treatment options and reviews recent data from prospective clinical studies testing new agents in first-line and relapsed follicular lymphoma. Finally, we assess the current role of immunochemotherapy and discuss the requirements for future clinical trials.

Hepatitis C virus infection is an independent prognostic factor in follicular lymphoma.

Hepatitis C virus (HCV) is a single-stranded RNA virus that not only affects hepatocytes, by B cells as well. It is thought that HCV is involved in the onset of B-cell lymphoma. The clinicopathological characteristics of HCV-positive diffuse large B-cell lymphoma (DLBCL) and HCV-positive splenic marginal zone lymphoma (SMZL) are known, but there has been no report on HCV-positive follicular lymphoma (FL). In this study, the clinicopathological characteristics of HCV-positive FL were examined in 263 patients with FL who were classified into a HCV-positive group with HCV antibody and negative groups without one. The number of patients with HCV-positive FL and HCV-negative FL was 10 (3.8%) and 253 (96.2%), respectively. The patients with HCV-positive FL commonly had more than one region of lymphadenopathy, Ann Arbor stage III/IV, hemoglobin <120 g/l, elevated lactate dehydrogenase level, and high-risk categorization of Follicular Lymphoma International Prognostic Index (FLIPI) than in patients with HCV-negative FL. Overall survival and progression-free survival were poorer in patients with HCV-positive FL than in those with HCV-negative FL (p < 0.0001 and 0.006, respectively). Also, multivariate analysis revealed that positive HCV antibody was a poor prognostic factor of OS. In conclusion, HCV-positive FL has unique clinical features and may have a great impact on the overall survival of affected patients.

Prognostic value of lymphocyte-to-monocyte ratio and neutrophil-to-lymphocyte ratio in follicular lymphoma: a retrospective cohort study

ObjectivesThe clinical course and prognosis of follicular lymphoma (FL) are diverse and associated with the patient’s immune response. We investigated the lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) as prognostic...

Fc-Epsilon Receptor (CD23) Expressing Follicular Dendritic Cells as a Main Prognostic Factor in Follicular Lymphoma

Fc-epsilon receptor (CD23)-expressing follicular dendritic cells is a main prognostic factor in follicular lymphoma. Falaleeva N. A., Osmanov E. A., Tupitsyn N. N. Federal State Budgetary Institute N. N. Blokhin Russian Cancer Research Center, Health Ministry of Russian Federation, Moscow, Russia SUMMARY Follicular dendritic cells, expressing FcεRII or CD23 (FcεRIIFDCs) as a component of non-tumor environment have been studied in 232 follicular lymphoma (FL) patients. FcεRIIFDCs were found in 87.5% of follicular lymphoma cases and were associated with a nodular pattern of tumor growth (p = 0.000), but not the cytological grade of lymphoma. There were no associations of FcεRIIFDC with clinical prognostic factors (FLIPI indices) or with bone marrow involvement in FL patients by histology. The presence of FcεRIIFDCs in tumor tissue was an independent prognostic factor according to treatment results, i.e. frequency of CR, duration of OS and PFS. Bone marrow involvement significantly worsened the prognosis in FcεRIIFDC-positive group of patients. We suggest a new prognostic index (FDC-IP) that allows biochemical identification of the following patient groups: FcεRIIFDC-positive patients without bone marrow involvement (good prognosis), FcεRIIF-DC-positive patients with bone marrow involvement (intermediate prognosis), FcεRIIFDC-negative patients (poor prognosis). These 3 groups significantly differ (p = 0.000) both in OS and in PFS. This is the first evidence of the possibility to assess tumor behavior and treatment results in FL according to lymphoma biochemical and other than clinical parameters.

Prognostic factors in follicular lymphoma: new tools to personalize risk.

Follicular lymphoma (FL) is the most common indolent lymphoma, and it has a long median overall survival (OS). However, the recent discovery of clinical and biological prognostic biomarkers in FL is shedding light on FL heterogeneity and the need for a precise and risk-stratified individual approach at diagnosis and relapse. Many FL patients who are asymptomatic with indolent disease can be vulnerable to the toxicity, emotional distress, and financial burden of overtreatment. Yet a subset of FL patients develop chemoresistance to standard chemoimmunotherapy, experience transformation to aggressive lymphoma and rapid progression, and represent the population most in need of novel therapies and curative approaches. Novel biomarkers that incorporate both clinical and genetic determinants of poor risk are being developed with the hope of identifying high-risk patients at diagnosis in order to offer biologically rational targeted therapies.

The Value of PET/CT in Detecting Bone Marrow Involvement in Patients With Follicular Lymphoma.

Follicular lymphoma (FL) is the 2nd most common type of lymphoma diagnosed in the Western World. Bone marrow (BM) involvement is an adverse prognostic factor in FL, routinely assessed by an arbitrary biopsy of the iliac crest. This study was aimed to investigate the role of positron emission tomography/computed tomography (PET/CT) in identifying BM involvement by FL.In this retrospective, single-center study we reviewed the records of consecutive patients with FL at diagnosis or relapse who underwent staging/restaging workup visual assessment of BM uptake was categorized as either normal, diffusely increased, or focally increased. Quantitative BM fluorine-18-fluro-deoxyglucose (FDG) uptake was measured using mean standardized uptake value (BM-SUVmean). The diagnosis of BM involvement was based on either BM histological findings or disappearance of increased uptake at end-treatment PET/CT in patients who responded to treatment.Sixty eight cases with FL were included. Sixteen (23.5%) had BM involvement, 13 (19.1%) had a biopsy proven involvement, and 3 (4.4%) had a negative BM biopsy, but increased medullary uptake that normalized post-treatment. BM FDG uptake in these patients was diffuse in 8 (50%) and focal in 8 (50%). Focal increased uptake was indicative of BM involvement; however, diffuse uptake was associated with 17 false positive cases (32.7%). Overall, visual assessment of BM involvement had a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 48.5%. On a quantitative assessment, BM-SUVmean was significantly higher in patients with BM involvement (SUVmean of 3.7 [1.7–6] vs 1.4 [0.4–2.65], P < 0.001). On receiver operator curve (ROC) analysis, BM-SUVmean > 2.7 had a PPV of 100% for BM involvement (sensitivity of 68%), while BM-SUVmean < 1.7 had an NPV of 100% (specificity of 73%).Visual assessment of PET/CT is appropriate for ruling out BM involvement by FL. Although focal increased uptake indicates marrow involvement, diffuse uptake is nonspecific. SUV measurement improves PET/CT diagnostic accuracy, identifying additional 19% of patients with BM involvement that would have been otherwise missed.

FilGAP, a Rac-specific Rho GTPase-activating protein, is a novel prognostic factor for follicular lymphoma.

FilGAP, a Rho GTPase-activating protein (GAP), acts as a mediator of Rho/ROCK (Rho-associated protein kinase)-dependent amoeboid movement, and its knockdown results in Rac-driven mesenchymal morphology. Herein, we focus on the possible roles of FilGAP expression in normal and malignant lymphocytes. Eighty-three cases of follicular lymphoma (FL), 84 of diffuse large B-cell lymphoma (DLBCL), and 25 of peripheral T-cell lymphoma (PTCL), as well as 10 of normal lymph nodes, were immunohistochemically investigated. In normal lymph nodes, FilGAP immunoreactivity was significantly higher in lymphocytes in the mantle zone as compared to those in the germinal center and paracortical areas. In contrast, the expression levels of both cytoplasmic and perinuclear Rac1 were significantly lower in the germinal center as compared to paracortical regions, suggesting that changes in the FilGAP/Rac axis may occur in B-cell lineages. In malignant lymphomas, FilGAP expression was significantly higher in B-cell lymphomas than PTCL, and the immunohistochemical scores were positively correlated with cytoplasmic Rac1 scores in FL and DLBCL, but not in PTCL. Patients with FL and germinal center B-cell-like (GCB)-type DLBCL showing high FilGAP scores had poor overall survival rates as compared to the low-score patients. Moreover, multivariate Cox regression analysis showed that a high FilGAP score was a significant and independent unfavorable prognostic factor in FL, but not in DLBCL. In conclusion, FilGAP may contribute to change in cell motility of B-lymphocytes. In addition, its expression appears to be useful for predicting the behavior of B-cell lymphoma, in particular FL.

Association of tumor-associated macrophages of M2 subtype with outcome in follicular lymphoma.

8078 Background: Current methods used to prognosticate patients with follicular lymphoma (FL) include the Follicular Lymphoma International Prognostic Index (FLIPI) and tumor grade. However, they do not provide information on the biological and molecular features of FL. Recent data suggest that high tumor-associated macrophages (TAM) content may be an adverse prognostic factor in FL. However, TAM consists of two main subtypes, M1 and M2, with the former related to pro-inflammatory properties while the latter, anti-inflammatory functions. Currently, the prognostic impact of each individual subtype has not been elucidated and this may be more important than looking at TAM alone. Methods: Tumor specimens of 98 patients with FL diagnosed between 2005 and 2009 were investigated using immunohistochemistry and fluorescence in-situ hybridization (FISH) using break-apart FISH probes targeting BCL2, BCL6, MYC and IgH genes. Tumor specimens expressing a higher proportion of CD68+/CD163- in one high power field were defined as M1 subtype and those that expressed a greater proportion of CD68+/CD163+ were denoted as M2 subtype. Results: Amongst the 98 patients, 60 (61%) were of the M2 subtype, 59% presented with advanced disease, 47% were grade 3 and the median age was 59 years (21 – 88 years). Baseline characteristics including grade, stage and recurrent translocations did not significantly differ between the M1 and M2 groups. Similarly, there was also no difference in terms of treatment received (both Rituximab and chemotherapy) between the two groups. Despite these similarities, with a median follow-up of 3.2 years, the 3-year overall survival (OS) was significantly different (M1, 100% vs M2, 85%; p &lt; 0.01). All 11 patients who died were of the M2 subtype (p=0.009). Conclusions: Our findings show that despite similar patient characteristics and treatment, there was, however, a statistically significant difference in OS, with the M2 subtype demonstrating an inferior outcome. The M2 TAM subtype rather than TAM alone may be a more important prognostic marker in FL, which could possibly be explained by its known biological anti-inflammatory function.

The Absolute Monocyte Count Predicts Overall Survival In Patients Newly Diagnosed with Follicular Lymphoma

Abstract 85▪▪This icon denotes a clinically relevant abstract Background:Follicular lymphoma (FL) is an indolent non-Hodgkin lymphoma (NHL) with a highly variable natural history. Clinical variables describing either patient- or tumor-specific characteristics, many of which are included in the Follicular Lymphoma International Prognostic Index (FLIPI), are used to risk-stratify patients at the time of diagnosis. However, characteristics of non-malignant cells present within the tumor microenvironment provide important prognostic information. For example, both immunohistochemistry and gene expression profiling studies demonstrate that lymphoma-associated macrophages (LAMs) are prognostically important in FL. As LAMs are monocyte-derived, we sought to determine whether the absolute monocyte count (AMC) obtained from a CBC at diagnosis is an adverse prognostic factor in FL. Methods:Consecutive patients with FL who were evaluated and treated at the Mayo Clinic, Rochester between 1998 and 2007 were considered for study participation. Study approval was granted by the Mayo Clinic Institutional Review Board. The primary objective of the study was to determine the significance of the AMC, obtained at the time of diagnosis from a standard complete blood count with differential, in predicting overall survival. The secondary study objective was to determine whether the AMC is an independently significant prognostic factor when compared with the FLIPI. Results:The median follow-up was 4.2 years (range: 2 months to 11 years) for the 355 patients included in this study. At diagnosis, 43%, 34% and approximately 23% of patients were classified as low-, intermediate- or high-risk by the FLIPI. The median AMC at diagnosis was 510/μL, with 8% of patients presenting with an absolute monocytosis. At diagnosis, 45% of patients were initially observed, 42% received combination chemotherapy or immunochemotherapy alone, while the remaining 13% underwent surgery or radiation.The AMC was evaluated as both a continuous and dichotomized variable on univariate analysis. The optimal cut-point for the AMC was determined to be 570/μL by ROC analysis and was used when analyzing the AMC as a dichotomized variable. A relative elevation in the AMC was associated with inferior overall survival, whether analyzed as a continuous or dichotomized variable, with hazard ratios (HR) of 1.002 (HR per unit change in AMC; 95% confidence interval 1.001–1.002; p=0.0002) and 3.4 (95% confidence interval 2.0–6.0; p<0.0001), respectively. The median OS for patients with an AMC <570/μL at diagnosis has not been reached, whereas a median OS of 10.2 years (95% confidence interval 7.8–11.2 years; p<0.0001) was observed for those patients with an AMC ≥570/μL. For comparison, median OS has not been reached for high-risk patients identified by the FLIPI. Among those patients who were initially observed, the median time to progression (TTP) was 31 months (95% confidence interval 25–37 months) for those with an AMC <570/μL at diagnosis. In contrast, patients with an AMC ≥570/μL experienced a significantly shorter TTP following initial observation, with a median TTP of 18 months (95% confidence interval 8–28 months; p=0.03). When adjusting for prognostic factors included in the FLIPI on multivariate analysis, the association between the AMC as a dichotomized variable and survival remained significant with a HR of 2.6 (95% confidence interval 1.5–4.6; p=0.001). When the FLIPI alone (high vs. low/intermediate) was analyzed on multivariate analysis, the AMC remained an independent predictor of survival (p<0.0001). Furthermore, the AMC provided additional prognostic information when superimposed upon the FLIPI. For example, a subset of patients classified as high-risk by the FLIPI were observed to have an OS comparable to low/intermediate risk patients identified by the FLIPI upon further risk-stratification by the AMC, with a 6-year OS of 80%. In contrast, high-risk FLIPI patients with an AMC ≥570/uL were observed to have a median OS of 4.2 years (95% confidence interval 2.7–7.2) and 6-year OS of 47%. Conclusions:The AMC is associated with overall survival in FL and is independent from the FLIPI on multivariate analysis. While the AMC did not appear inferior to the FLIPI in identifying high-risk patients, it may be most helpful when used in conjunction with the FLIPI. These results further support the central role of nonneoplastic myeloid-lineage cells in FL biology. Disclosures:No relevant conflicts of interest to declare.

Follicular programmed death 1–positive lymphocytes in the tumor microenvironment are an independent prognostic factor in follicular lymphoma

We enumerated programmed death 1 (PD-1)-positive follicular helper T cells, a potentially important regulator of immune response, in the tumor microenvironment of a series of 91 newly diagnosed follicular lymphomas managed at a single institution. Clinical data were obtained for sex, age, Follicular Lymphoma International Prognostic Index (FLIPI) risk group, presence of bulky disease, presence of B symptoms, and overall survival. Immunohistochemical staining for PD-1 was performed on tissue microarray sections, and the mean number of follicular PD-1-positive cells per 9 high-power fields (1000×, 3 follicles with 3 fields per follicle) was quantified. B-cell CLL/lymphoma 2 (BCL-2) expression, CD68(+) extrafollicular lymphoma-associated macrophages, and forkhead box P3 (FOXP3)+ regulatory T cells were evaluated as reported previously. Ninety-one patients were evaluated, with a median age at diagnosis of 58 years and median survival of 11.6 years. PD-1-positive cells correlated with the number of FOXP3+ regulatory T cells (P = .01). On multivariate analysis, independent poor prognostic factors were age 55 years or greater (hazard ratio, 2.77; 95% confidence interval, 1.34-5.73; P = .006), bulky disease (hazard ratio, 2.27; 95% confidence interval, 1.03-5.00; P = .04), CD68(+) extrafollicular lymphoma-associated macrophages greater than 16.8 cells/high-power field (hazard ratio, 2.15; 95% confidence interval, 1.14-4.06; P = .02), and PD-1-positive cells greater than 35.6 cells/high-power field (hazard ratio, 1.98; 95% confidence interval, 1.09-3.60; P = .03). These factors allowed construction of a risk score defining 3 distinct prognostic groups with 10-year overall survival of 85%, 60%, and 15%. PD-1-positive follicular helper T cells and CD68(+) extrafollicular lymphoma-associated macrophages appear to predict overall survival in follicular lymphoma, and our findings support strategies aimed at modulating their function in follicular lymphoma. Future studies, performed prospectively on uniformly treated patient cohorts, should be performed to validate these findings.

Abstract 5043: Effects of a novel PI3 kinase/mTOR inhibitor on proliferation and pAKT signaling in canine lymphoma

Abstract PF-04691503 is a dual inhibitor of both PI3K and mTOR, inhibits PI3K signaling in cancer cell lines, and exhibits in vitro and in vivo anti-proliferative activity in PI3K-pathway driven cell lines. It is a nanomolar inhibitor of all 4 isoforms of the catalytic subunit of PI3K and of both TORC1 and TORC2. Anti-cancer activity of the inhibitor is hypothesized to be through inhibition of survival, proliferative, and anti-apoptotic processes. Phosphorylation of the protein kinase, Akt, is associated with activation of the phosphatidyl 3-kinase (PI-3K)/mammalian target of rapamycin (mTOR) signaling pathway, which plays a role in cell proliferation (Witzig and Kaufmann 2006). Recent studies by Gulmann et al (2005) showed increased pAKT in human lymphoma samples, and those of Rassidakis et al (2005) suggested that inhibition of Akt phosphorylation (pAKT) may be of value in the treatment of lymphoma. Using flow cytometry we report that cells obtained from 10 of 11 lymph node biopsies of dogs with lymphoma exhibit detectable pAKT using a phospho-Akt (Ser473) antibody, compared to an IgG isotype control or a competative phospho-Akt (Ser473) blocking peptide. Cells from normal canine lymph nodes do not exhibit detectable pAKT. The majority of the pAKT signal was generated from lymphoblasts present in the malignant, but not in the normal, lymph nodes. In separate studies, lymph node cells obtained from healthy dogs and dogs with lymphoma were stimulated in vitro with the mitogen, Con A. The novel PI3K/mTOR dual inhibitor, PF-04691503, produced dose dependent inhibition of proliferation as exemplified in a dog with T-cell lymphoma (EC50 = 18 nM)) and in a normal dog (EC50 = 53 nM)). No pAKT signal could be detected in peripheral blood mononuclear cells, from normal or lymphoma patients stimulated with hu-IGF-1 (the endogenous ligand for PI3), Con-A or LPS. These data suggest that PI-3 kinase and pAKT (1) are activated in canine lymphoma, (2) play a role in the lymphoproliferation associated with this disease, (3) represent legitimate targets for therapeutic intervention in lymphoma, and (4) can be studied ‘translationally’ in dogs as a model for humans. Gulmann C, Espina V, Petricoin E, et al. Proteomic analysis of apoptotic pathways reveals prognostic factors in follicular lymphoma. Clin Cancer Res 11:5847-5855, 2005. Rassidakis GZ, Feretzaki M, Atwell C, et al. Inhibition of Akt increases p27 Kip1 levels and induces cell cycle arrest in anaplastic large cell lymphoma. Blood 105:827-829, 2005. Witzig TE and Kaufmann SH. Inhibition of phosphatidyl 3-kinase (PI-3K)/mammalian target of rapamycin (mTOR) pathway in hematologic malignancies. Current Treatment Options in Oncology 7:285-294, 2006. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5043.

Prognostic Factors in Follicular Lymphoma

Follicular lymphoma (FL) is one of the most common types of non-Hodgkin's lymphoma. It is usually diagnosed at an advanced stage, for which many treatment options exist, however, no curative standard therapy has been identified. The outcome is highly variable with a median survival of approximately 10 years. The life expectancy of patients with FL has been extended with the use of rituximab, a monoclonal antibody targeting the CD20 antigen on FL cells, but there remains a group of patients who fail to respond to chemoimmunotherapy and die early of their disease. Transformation of FL to an aggressive histology is an important event with high morbidity and mortality. The Follicular Lymphoma International Prognostic Index has become the clinically useful prognostic tool, but gives only a rough estimate of expected outcome. There is a need for useful biomarkers for prediction of the disease course of single patients to individualize therapy, especially in the new era of chemoimmunotherapy.

Follicular PD-1+ Lymphocytes in the Tumor Microenvironment Are An Independent Prognostic Factor in Follicular Lymphoma.

Abstract 134The tumor microenvironment has been recognized as important in the pathobiology of follicular lymphoma (FL). Indeed, the role of extrafollicular lymphoma-associated macrophages (ef-LAMs) and FOXP3+ regulatory T-cells (Tregs) as predictors of overall survival in FL was previously reported by our group and others. We sought to further evaluate the role of specific T-cell subsets in our patient series. To this end we enumerated PD-1+ follicular helper T-cells (Tfhs), a potentially important regulator of immune response, in the tumor microenvironment in a series of 91 newly diagnosed FLs. Initial biopsies from 91 FL patients diagnosed between 9/1/85 and 12/13/02 were evaluated. FL grade 3B cases were excluded. Clinical data was obtained for gender, age, FLIPI risk group, presence of bulky disease, presence of B-symptoms and overall survival (OS). Immunohistochemical staining for PD-1 was performed on tissue microarray sections and the mean number of follicular PD-1+ cells per 9 high power fields (1000x, 3 follicles with 3 fields per follicle) was quantified. Recursive partitioning analysis was then performed to determine an optimal break-point for PD-1. BCL2 expression, ef-LAMs and FOXP3+ Tregs were evaluated as reported by us previously. The Cox proportional hazards model was used to determine significant univariate and multivariate prognostic risk factors, using P≤ 0.10 as the criterion for inclusion and retention in the multivariate analysis. The Kaplan-Meier method was used to summarize OS. 54% of patients were male with a median age at diagnosis of 58 years (range 24–89 years). The distribution of FLIPI scores was 35% low, 27% intermediate, and 37% high. The number of PD-1+ Tfhs was variable (median number of PD-1+ cells = 35.6, range 4.4 – 91.2). Number of PD-1+ cells correlated with number of Tregs (P=.01) and marginally with lack of BCL2 (P=.07) but not with other clinical or pathologic variables. On univariate analysis, age ≥ 55 (P=0.004), increasing FLIPI risk group (P=0.03), bulky disease (>10 cm; P=0.05), lack of BCL2 (P=.01), high ef-LAMs (>16.8/hpf, P=.003), and high PD-1+ cells (>35.6/hpf, P=0.10) were all associated with decreased OS. On multivariate analysis, independent poor prognostic risk factors were: age ≥55 (hazard ratio[HR]=2.76, 95% confidence interval [CI] = 1.33–5.76, P=.007), high ef-LAMs (HR=2.13, 95%CI = 1.11–4.07, P=.02) bulky disease (HR=2.10, 95% CI 0.91–4.83, P=.08), and high PD-1+ cells (HR 2.04, 95% CI=1.11–3.75, P=.02). A prognostic model based on the number of risk factors present can be constructed with patients having 0, 1-2 or 3-4 risk factors defining 3 distinct prognostic groups (Figure 1). In summary, cellular constituents of the FL microenvironment play an important role in the biology of FL. A combination of standard clinical and biologic factors that include Tfhs and ef-LAMs appear to predict OS in FL. Given the putative role for Tfhs in down-regulating the immune response, these data support strategies aimed at modulating Tfh function in FL. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Elevated Serum sIL-2Ra Levels Facilitate IL-2 Signaling and Contribute to Impaired Tumor Immunity in B-Cell Non-Hodgkin Lymphoma (NHL).

Abstract 281Elevated serum levels of soluble interleukin-2 receptor alpha (sIL-2Ra) have been shown to be a poor prognostic factor in various malignancies and sIL-2Ra levels have generally correlated with tumor bulk and advanced stage of disease. In a clinical trial of single agent rituximab in previously untreated follicular lymphoma (FL) patients, we found that sIL-2Ra levels were elevated compared to controls and increased sIL-2Ra levels prior to treatment were associated with a poor outcome. The mean sIL-2Ra level (+/− standard deviation) in untreated FL patients (n=32) was 2.13 ng/ml (+/− 1.81) and 1.09 ng/ml (+/− 1.53) for normal controls (n=16). The time to progression for previously untreated FL patients after 4 doses of rituximab was 12 months for patients with sIL-2Ra levels above the mean compared to 40 months for patients with low sIL-2Ra levels (p=0.003) confirming that elevated sIL-2Ra is a poor prognostic factor in FL. To explore the mechanism by which sIL-2Ra may contribute to a poor prognosis, we determined the source of sIL-2Ra and whether sIL-2Ra facilitates interleukin-2 (IL-2) signaling. Based on our previous work showing that IL-2 induces Foxp3 expression, we particularly evaluated whether sIL-2Ra may bind IL-2 and contribute to impaired anti-tumor immunity by promoting Treg cell development.We found that sIL-2Ra could be detected by ELISA in the culture medium of IL-2Ra-expressing cell lines such as SuDHL1 and Karpas299 and that activation of these cells with PMA/Ionomycin significantly increased sIL-2Ra levels in the culture medium. Production of sIL-2Ra was associated with an attenuation of surface IL-2Ra expression on SuDHL1 and Karpas299 cells suggesting that surface IL-2Ra is the source of sIL-2Ra. Next, using histo-tagged sIL-2R, we tested whether the complex between sIL-2Ra and IL-2 was able to bind to IL-2R on the malignant cell. We found that sIL-2Ra bound IL-2 and that the complex could be detected on the surface of IL-2R-expressing cells. We then compared the signaling of the sIL-2Ra/IL-2 complex to that of IL-2 alone. As expected, we found that IL-2 stimulated cell proliferation, enhanced STAT5 phosphorylation and upregulated Foxp3 expression in CD4+ T cells in a dose-dependent manner. Administration of an anti-IL-2 antibody attenuated these effects. In contrast, sIL-2Ra alone had little effect on cell proliferation, STAT5 phosphorylation and Foxp3 expression. However, the addition of sIL-2Ra to IL-2 prior to incubation with IL-2R-expressing cells enhanced IL-2-mediated phosphorylation of STAT5 and Foxp3 expression in CD4+ T cells. Compared to IL-2 alone, treatment with sIL-2Ra (25ng/ml) and IL-2 (25ng/ml) increases the number of CD4+ T cells with phosphorylation of STAT5 from 7.9% to 17.4%.Taken together, these results indicate that sIL-2R plays an active biologic role in FL by binding IL-2 and promoting IL-2 signaling rather than depleting IL-2 and blocking its function. Given the findings that IL-2 strongly induces Foxp3 expression and promotes Treg cell development and that Treg cells suppress anti-tumor immunity, we conclude that elevated serum levels of sIL-2Ra facilitate IL-2 signaling and thereby contribute to a poor prognosis in FL. Disclosures:No relevant conflicts of interest to declare.