Applicability of the International Index for aggressive lymphomas to patients with low-grade lymphoma

A novel prognostic index for sporadic Burkitt lymphoma in adult patients: a real-word multicenter study

Background

Adult sporadic Burkitt lymphoma (BL) is a rare but highly aggressive subtype of lymphoma which lacks its own unique prognostic model. Systemic inflammatory biomarkers have been confirmed as prognostic markers in several types of malignancy. Our objective was to explore the predictive value of pretreatment inflammatory biomarkers and establish a novel, clinically applicable prognostic index for adult patients with sporadic BL.

Methods

We surveyed retrospectively 336 adult patients with newly diagnosed sporadic BL at 8 Chinese medical centers and divided into training cohort (n = 229) and validation cohort (n = 107). The pretreatment inflammatory biomarkers were calculated for optimal cut-off value. The association between serum biomarkers and overall survival (OS) was analyzed by Kaplan–Meier curves and Cox proportional models. The risk stratification was defined based on normal LDH level, Ann Arbor stage of I and completely resected abdominal lesion or single extra-abdominal mass < 10 cm.

Results and conclusions

Univariate and multivariate analyses revealed that platelets< 254 × 10⁹/L, albumin< 40 g/L, lactate dehydrogenase≥334 U/L independently predicted unfavorable OS. We used these data as the basis for the prognostic index, in which patients were stratified into Group 1 (no or one risk factor), Group 2 (two risk factors), or Group 3 (three risk factors), which were associated with 5-year OS rates of 88.1, 72.4, and 45%, respectively. In the subgroup analysis for high-risk patients, our prognostic model results showed that high-risk patients with no more than one adverse factor presented a 5-year survival rate of 85.9%, but patients with three adverse factors had a 5-year survival rate of 43.0%. Harrell’s concordance index (C-index) of the risk group score was 0.768. Therefore, the new prognostic model could be used to develop risk-adapted treatment approaches for adult sporadic BL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09144-1.

Prognostic ability of five clinical risk scores in follicular lymphoma: A single-center evaluation

With the intention of identifying follicular lymphoma (FL) patients at higher risk of progression, early relapse (POD24), histological transformation (HT) or death, multiple risk scores (RS) have been proposed. However, it has not yet been established whether any of them globally outperforms the others. We evaluated the clinical utility and statistical performance of the five most widely used clinical scores (IPI, ILI, FLIPI, FLIPI2, PRIMA-PI) in a single-center series of 414 grade 1-3A FL patients diagnosed in the rituximab era. Overall concordance (proportion of patients allocated to the same risk category by all five RS) was 24%. FLIPI and FLIPI2 were predictive of time to first treatment. All five scores were predictive of response, POD24, progression-free, and OS, while only FLIPI predicted HT. IPI identified a small subset (7%) of truly high-risk patients (10-year OS of 16%). In subgroup analyses, we showed that ILI is useful in the prognostication of limited-disease patients, and PRIMA-PI is an age-independent score that can identify a high-risk subset of older patients. Performance metrics were slightly better for IPI in terms of calibration (Harrell's c-index 0.73), without major differences among RS regarding other parameters. Although the incorporation of molecular and imaging data will continue to refine the stratification of FL patients, FLIPI remains the most powerful clinical prognostic index in the rituximab era, predicting the greatest number of endpoints.

Past, present and future of prognostic scores in follicular lymphoma

Although most follicular lymphoma (FL) patients have prolonged survival, the identification of those at risk of early progression, multiple relapses or histological transformation is essential for the improvement of long-term outcomes. In this sense, a plethora of prognostic indexes have been developed in the last decades. However, determining which one is more accurate and clinically meaningful remains a challenge. Key factors for the external validity of available indexes include characteristics of the study population, treatment intervention, and design of the study. While initial risk scores were composed of clinical, biochemical, and hematological variables, genomic and imaging data have been incorporated in recent years. Despite an obvious step forward in the knowledge of the natural history and biology of FL, predictions remain inaccurate. Further research will likely incorporate information from circulating tumor DNA and artificial intelligence models to refine the prognostic classification of the heterogeneous FL population.

Clinical and Biological Prognostic Factors in Follicular Lymphoma

Follicular lymphoma comprises approximately 20-30% of all cases of B-cell lymphomas. Median survival has improved significantly in the modern era. Prognostic factors include histologic grade, cytogenetics, molecular mutations, the tumor microenvironment, and tumor burden. Clinical prognostic indices are available and increasingly incorporate genetic information. Prognostic factors also arise during the course of treatment. Early progression within 24 months of initial chemoimmunotherapy is an adverse prognostic marker of inferior survival. Other high-risk populations include those with double refractory disease or those with high risk of transformation to diffuse large B-cell lymphoma.

Prolonged survival in the absence of disease-recurrence in advanced-stage follicular lymphoma following chemo-immunotherapy: 13-year update of the prospective, multicenter randomized GITMO-IIL trial

A prospective trial conducted in the period 2000-2005 showed no survival advantage for high-dose chemotherapy with rituximab and autograft (R-HDS) versus conventional chemotherapy with rituximab (CHOP-R) as first-line therapy in 134 high-risk follicular lymphoma patients aged <60 years. The study has been updated at the 13-year median follow up. As of February 2017, 88 (66%) patients were alive, with overall survival of 66.4% at 13 years, without a significant difference between R-HDS (64.5%) and CHOP-R (68.5%). To date, 46 patients have died, mainly because of disease progression (47.8% of all deaths), secondary malignancies (3 solid tumor, 9 myelodysplasia/acute leukemia; 26.1% of all deaths), and other toxicities (21.7% of all deaths). Complete remission was documented in 98 (73.1%) patients and associated with overall survival, with 13-year estimates of 77.0% and 36.8% for complete remission versus no-complete remission, respectively. Molecular remission was documented in 39 (65%) out of 60 evaluable patients and associated with improved survival. In multivariate analysis, complete remission achievement had the strongest effect on survival (P<0.001), along with younger age (P=0.002) and female sex (P=0.013). Overall, 50 patients (37.3%) survived with no disease recurrence (18 CHOP-R, 32 R-HDS). This follow up is the longest reported on follicular lymphoma treated upfront with rituximab-chemotherapy and demonstrates an unprecedented improvement in survival compared to the pre-rituximab era, regardless of the use of intensified or conventional treatment. Complete remission was the most important factor for prolonged survival and a high proportion of patients had prolonged survival in their first remission, raising the issue of curability in follicular lymphoma. (Registered at clinicaltrials.gov identifier: 00435955)

Risk Factors for Transformation to Higher-Grade Lymphoma and Its Impact on Survival in a Large Cohort of Patients With Marginal Zone Lymphoma From a Single Institution

PURPOSE

Given the paucity of data on higher-grade transformation (HGT) to aggressive lymphoma in patients with marginal zone lymphoma (MZL), we report on a large cohort of patients, identify risk factors, and determine HGT impact on overall survival (OS).

METHODS

We analyzed 453 patients with biopsy-proven MZL seen at our institution between 1995 and 2016. Kaplan-Meier, Cox proportional hazards regression, and competing risk methods were used in analyses of time-to-event outcomes.

RESULTS

Thirty-four patients (7.5%) had biopsy-proven HGT to diffuse large B-cell lymphoma, including seven (21%) diagnosed at the time of initial MZL diagnosis. Among 27 incident patients, median time to HGT was 29 months (range, 1.3 to 135 months). Higher risk of HGT was observed in those with nodal/splenic MZL (subdistribution hazard ratio [SHR], 2.60; P = .023). On multivariable competing risk analysis, elevated lactate dehydrogenase (SHR, 2.71), more than four nodal sites (SHR, 2.97), and failure to achieve complete remission (CR) after initial treatment (SHR, 3.76) conveyed significantly higher risk for HGT ( P < .02). International Prognostic Index (IPI), Follicular Lymphoma IPI, and Mucosa-Associated Lymphoid Tissue Lymphoma IPI were only significant predictors of HGT univariably. Patients with HGT had shorter OS (5-year rate, 65% v 86%; P < .001). Patients who presented with HGT within 12 months since MZL diagnosis had shorter OS than those with HGT at MZL diagnosis combined with those with HGT more than 12 months later (4-year rate, 43% v 81%, P < .001). Non-CR and higher scores of IPI, Follicular Lymphoma IPI, and Mucosa-Associated Lymphoid Tissue Lymphoma IPI were the main significant predictors for shorter progression-free survival and OS.

CONCLUSION

Failure to achieve CR after initial treatment, elevated lactate dehydrogenase, and more than four nodal sites at the time of MZL diagnosis are the main predictors of increased risk of HGT. Patients with HGT have shorter OS.

Unmet needs in the first-line treatment of follicular lymphoma

For the majority of patients with newly diagnosed follicular lymphoma (FL), current treatments, while not curative, allow for long remission durations. However, several important needs remain unaddressed. Studies have consistently shown that ∼20% of patients with FL experience disease progression within 2 years of first-line treatment, and consequently have a 50% risk of death in 5 years. Better characterization of this group of patients at diagnosis may provide insight into those in need of alternate or intensive therapies, facilitate a precision approach to inform clinical trials, and allow for improved patient counseling. Prognostic methods to date have employed clinical parameters, genomic methods, and a wide assortment of biological and biochemical markers, but none so far has been able to adequately identify this high-risk population. Advances in the first-line treatment of FL with chemoimmunotherapy have led to a median progression-free survival (PFS) of approximately 7 years; creating a challenge in the development of clinical trials where PFS is a primary end point. A surrogate end point that accurately predicts PFS would allow for new treatments to reach patients with FL sooner, or lessen toxicity, time, and expense to those patients requiring little to no therapy. Quality of response to treatment may predict PFS and overall survival in FL; as such complete response rates, either alone or in conjunction with PET imaging or minimal residual disease negativity, are being studied as surrogates, with complete response at 30 months after induction providing the strongest surrogacy evidence to date. A better understanding of how to optimize quality of life in the context of this chronic illness is another important focus deserving of further study. Ongoing efforts to address these important unmet needs are herein discussed.

A simplified scoring system in de novo follicular lymphoma treated initially with immunochemotherapy

In follicular lymphoma (FL), no prognostic index has been built based solely on a cohort of patients treated with initial immunochemotherapy. There is currently a need to define parsimonious clinical models for trial stratification and to add on biomolecular factors. Here, we confirmed the validity of both the follicular lymphoma international prognostic index (FLIPI) and the FLIPI2 in the large prospective PRIMA trial cohort of 1135 patients treated with initial R-chemotherapy ± R maintenance. Furthermore, we developed a new prognostic tool comprising only 2 simple parameters (bone marrow involvement and β₂-microglobulin [β₂m]) to predict progression-free survival (PFS). The final simplified score, called the PRIMA-PI (PRIMA-prognostic index), comprised 3 risk categories: high (β₂m > 3 mg/L), low (β₂m ≤ 3 mg/L without bone marrow involvement), and intermediate (β₂m ≤ 3 mg/L with bone marrow involvement). Five-year PFS rates were 69%, 55%, and 37% in the low-, intermediate-, and high-risk groups, respectively (P < .0001). In addition, achieving event-free survival (EFS) or not at 24 months (EFS24) was a strong posttreatment prognostic parameter for subsequent overall survival, and the PRIMA-PI was correlated with EFS24. The results were confirmed in a pooled external validation cohort of 479 patients from the FL2000 LYSA trial and the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence Molecular Epidemiology Resource. Five-year EFS in the validation cohort was 77%, 57%, and 44% in the PRIMA-PI low-, intermediate-, and high-risk groups, respectively (P < .0001). The PRIMA-PI is a novel and easy-to-compute prognostic index for patients initially treated with immunochemotherapy. This could serve as a basis for building more sophisticated and integrated biomolecular scores.

Platelet to lymphocyte ratio (PLR) retains independent prognostic significance in advanced stage marginal zone lymphoma patients treated with rituximab, cyclophosphamide, vincristine, and prednisone combination chemotherapy (R-CVP): Consortium for Improving Survival of Lymphoma trial

Background

Rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP) is one of the effective chemotherapeutic regimens for patients with advanced stage marginal zone lymphoma (MZL). However, prognostic factors that affect the outcome of treatment for MZL are not well understood.

Methods

Between August 2006 and June 2013, patients with newly diagnosed stage III and IV MZL treated with R-CVP as a first-line therapy from 15 institutions were retrospectively analyzed. Patients' clinical and laboratory data at diagnosis were collected by review of medical records.

Results

A total of 80 patients were analyzed. Bone marrow involvement was observed in 30% cases. Twelve patients (15%) had nodal MZL, and 41.3% patients exhibited multiple mucosa-associated lymphoma tissue sites. Overall response rate was 91.3%, including 73.8% achieving complete response. Advanced MZL patients treated with R-CVP showed a 3-year progression-free survival (PFS) rate of 69.6%. Prognostic markers significantly affecting PFS in univariate analysis were platelet to lymphocyte ratio (PLR, <95 vs. ≥95, P=0.014), serum albumin (≤3.9 vs. >3.9 g/dL, P=0.008), and the International Prognostic Index (IPI) score (1 vs. 2–4, P=0.032). In multivariate analysis, only PLR (<95 vs. ≥95, HR 0.367, 95% CI, 0.139–0.971, P=0.043) was an independent risk factor for PFS.

Conclusion

PLR ≥95 at diagnosis is an independent prognostic marker for PFS in advanced stage MZL patients treated with R-CVP. This marker may aid clinicians in predicting the response to R-CVP chemotherapy in stage III and IV MZL patients.

A MALT lymphoma prognostic index

There are no widely accepted prognostic indices for extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). This study aimed to develop and validate a specific prognostic tool to personalize and optimize treatment of patients with MALT lymphoma. A prognostic index was built by Cox regression (stepwise selection) using data from 401 patients enrolled in the international randomized International Extranodal Lymphoma Study Group 19 (IELSG-19) trial (NCT 00210353). A validation set, including 633 patients, was obtained by merging 3 independent cohorts of MALT lymphoma patients. The 3 individual features maintaining the greatest prognostic significance for event-free survival (EFS, the main endpoint of the IELSG-19 trial) were age ≥70 years (hazard ratio [HR], 1.72; 95% confidence interval [CI], 1.26-2.33), Ann Arbor stage III or IV (HR, 1.79; 95% CI ,1.35-2.38), and an elevated lactate dehydrogenase level (HR, 1.87; 95% CI, 1.27-2.77). The prognostic index (MALT-IPI) constructed using these 3 parameters identified 3 groups: low, intermediate, and high risk (corresponding to the presence of 0, 1, or ≥2 of these factors, respectively). The 5-year EFS rates in the low-, intermediate-, and high-risk groups were 70%, 56%, and 29%, respectively. The MALT-lymphoma International Prognostic Index (MALT-IPI) also significantly discriminated between patients with different progression-free, overall, and cause-specific survival. The prognostic utility was retained in gastric and nongastric lymphomas, in each treatment arm (chlorambucil, rituximab, and rituximab plus chlorambucil), and was confirmed in the validation set. The new index, MALT-IPI, is a simple, accessible, and effective tool to identify MALT lymphoma patients at risk of poor outcomes. It may help define appropriate treatment approaches for individual patients.

Thirty-Month Complete Response as a Surrogate End Point in First-Line Follicular Lymphoma Therapy: An Individual Patient-Level Analysis of Multiple Randomized Trials

Purpose Follicular lymphoma (FL) is an indolent cancer, with effective but rarely curative treatment options. As a standard study end point for first-line FL therapy, progression-free survival (PFS) requires extended follow-up (median PFS, > 7 years). To provide patients with earlier access to newer therapies, an earlier end point to expedite clinical trials is needed. Our objective was to formally assess the complete response rate at 30 months (CR30) after initiation of induction therapy as a potential surrogate end point for PFS in first-line FL therapy. Patients and Methods We analyzed individual patient data from 13 randomized multicenter trials of induction and maintenance regimens in first-line FL therapy published after 1990 and with sufficient data to evaluate whether CR30 could predict treatment effects on PFS. Correlation of the CR30 odds ratio with the PFS hazard ratio was evaluated by both linear regression (R²_WLS) and bivariate copula (R²_Copula) models. Prespecified criteria for surrogacy required either R²_WLS or R²_Copula ≥ 0.80, with a lower-bound 95% CI > 0.60. Results Data from eight induction and five maintenance randomized trials in 3,837 evaluable patients were analyzed. The prespecified surrogacy threshold was met, with an R²_WLS of 0.88 (95% CI, 0.77 to 0.96) and an R²_Copula of 0.86 (95% CI, 0.72 to 1.00). Multiple sensitivity and supplemental analyses supported the robustness of the findings. A minimum 11% absolute improvement in CR30 from a 50% control rate predicted a significant treatment effect on PFS (hazard ratio, 0.69). Conclusion This large, prospective, pooled analysis of randomized chemotherapy, immunotherapy, and chemoimmunotherapy trials demonstrates that CR30 is a surrogate end point for PFS in first-line FL treatment trials. Use of this end point may expedite therapeutic development with the intent of bringing novel therapies to this patient population years before PFS results are mature.

Integration of gene mutations in risk prognostication for patients receiving first-line immunochemotherapy for follicular lymphoma: a retrospective analysis of a prospective clinical trial and validation in a population-based registry

BACKGROUND

Follicular lymphoma is a clinically and genetically heterogeneous disease, but the prognostic value of somatic mutations has not been systematically assessed. We aimed to improve risk stratification of patients receiving first-line immunochemotherapy by integrating gene mutations into a prognostic model.

METHODS

We did DNA deep sequencing to retrospectively analyse the mutation status of 74 genes in 151 follicular lymphoma biopsy specimens that were obtained from patients within 1 year before beginning immunochemotherapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). These patients were recruited between May 4, 2000, and Oct 20, 2010, as part of a phase 3 trial (GLSG2000). Eligible patients had symptomatic, advanced stage follicular lymphoma and were previously untreated. The primary endpoints were failure-free survival (defined as less than a partial remission at the end of induction, relapse, progression, or death) and overall survival calculated from date of treatment initiation. Median follow-up was 7·7 years (IQR 5·5-9·3). Mutations and clinical factors were incorporated into a risk model for failure-free survival using multivariable L1-penalised Cox regression. We validated the risk model in an independent population-based cohort of 107 patients with symptomatic follicular lymphoma considered ineligible for curative irradiation. Pretreatment biopsies were taken between Feb 24, 2004, and Nov 24, 2009, within 1 year before beginning first-line immunochemotherapy consisting of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP). Median follow-up was 6·7 years (IQR 5·7-7·6).

FINDINGS

We established a clinicogenetic risk model (termed m7-FLIPI) that included the mutation status of seven genes (EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP, and CARD11), the Follicular Lymphoma International Prognostic Index (FLIPI), and Eastern Cooperative Oncology Group (ECOG) performance status. In the training cohort, m7-FLIPI defined a high-risk group (28%, 43/151) with 5-year failure-free survival of 38·29% (95% CI 25·31-57·95) versus 77·21% (95% CI 69·21-86·14) for the low-risk group (hazard ratio [HR] 4·14, 95% CI 2·47-6·93; p<0·0001; bootstrap-corrected HR 2·02), and outperformed a prognostic model of only gene mutations (HR 3·76, 95% CI 2·10-6·74; p<0·0001; bootstrap-corrected HR 1·57). The positive predictive value and negative predictive value for 5-year failure-free survival were 64% and 78%, respectively, with a C-index of 0·80 (95% CI 0·71-0·89). In the validation cohort, m7-FLIPI again defined a high-risk group (22%, 24/107) with 5-year failure-free survival of 25·00% (95% CI 12·50-49·99) versus 68·24% (58·84-79·15) in the low-risk group (HR 3·58, 95% CI 2·00-6·42; p<0.0001). The positive predictive value for 5-year failure-free survival was 72% and 68% for negative predictive value, with a C-index of 0·79 (95% CI 0·69-0·89). In the validation cohort, risk stratification by m7-FLIPI outperformed FLIPI alone (HR 2·18, 95% CI 1·21-3·92), and FLIPI combined with ECOG performance status (HR 2·03, 95% CI 1·12-3·67).

INTERPRETATION

Integration of the mutational status of seven genes with clinical risk factors improves prognostication for patients with follicular lymphoma receiving first-line immunochemotherapy and is a promising approach to identify the subset at highest risk of treatment failure.

FUNDING

Deutsche Krebshilfe, Terry Fox Research Institute.

Long-term outcomes and patterns of relapse of early-stage extranodal marginal zone lymphoma treated with radiation therapy with curative intent

PURPOSE

To report the long-term outcome and patterns of relapse of a large cohort of marginal zone lymphoma (MZL) patients treated with curative-intent radiation therapy (RT) alone.

PATIENTS AND METHODS

We reviewed the charts of 490 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to our institution. Of those, 244 patients (50%) were treated with RT alone. Pathology was confirmed by hematopathologists at our institution. Patient and disease factors were analyzed for association with relapse-free survival (RFS) and overall survival (OS).

RESULTS

Median age of the cohort was 59 years, and median follow-up was 5.2 years. Ann Arbor stage was IE in 92%. Most common disease sites were stomach (50%), orbit (18%), non-thyroid head-and-neck (8%), skin (8%), and breast (5%). Median RT dose was 30 Gy. Five-year OS and RFS were 92% and 74%, respectively. Cumulative incidence of disease-specific death was just 1.1% by 5 years. Sixty patients (24%) developed relapse of disease; 10 were in the RT field. Crude rate of transformation to pathologically confirmed large-cell lymphoma was 1.6%. On multivariable analysis, primary disease site (P=.007) was independently associated with RFS, along with age (P=.04), presence of B-symptoms (P=.02), and International Prognostic Index risk group (P=.03). All disease sites except for head-and-neck had worse RFS relative to stomach.

CONCLUSION

Overall and cause-specific survival are high in early-stage extra-nodal MZL treated with curative RT alone. In this large cohort of 244 patients, most patients did not experience relapse of MZL after curative RT; when relapses did occur, the majority were in distant sites. Stomach cases were less likely to relapse than other anatomic sites. Transformation to large-cell lymphoma was rare.

Prognostic assessment in patients with indolent B-cell lymphomas

Follicular lymphoma (FL) is an indolent lymphoma with long median survival. Many studies have been performed to build up prognostic scores potentially useful to identify patients with poorer outcome. In 2004, an international consortium coordinated by the International Follicular Lymphoma Prognostic Factor project was established and a new prognostic study was launched (FLIPI2) using progression-free survival (PFS) as main endpoint and integrating all the modern parameters prospectively collected. Low-grade non-Hodgkin lymphomas were once considered as a heterogenous group of lymphomas characterized by an indolent clinical course. Each entity is characterized by unique clinicobiologic features. Some studies have been focused on prognostic factors in single lymphoma subtypes, with the development of specific-entity scores based on retrospective series, for instance splenic marginal zone lymphoma (SMZL). A widely accepted prognostic tool for clinical usage for indolent non-follicular B-cell lymphomas is largely awaited. In this paper we summarized the current evidence regarding prognostic assessment of indolent follicular and non-follicular lymphomas.

Prognostic significance of biochemical markers in African Burkitt's lymphoma

BACKGROUND AND PURPOSE Endemic Burkitt's lymphoma (eBL) remains the prevalent form of paediatric cancer in tropical Africa with subtle pathological differences. This calls for intensified efforts to validate the global prognostic markers within local settings for improved cancer treatment and survival. This study proposes prognostic markers for enhanced eBL treatment and management. PATIENTS AND METHOD One hundred and eighty histologically and/or clinically diagnosed BL patients at Komfo Anokye Teaching Hospital, Kumasi, Ghana were eligible for this cross-sectional eight-year retrospective study. Biochemical, clinical and demographic data, before chemotherapy administration, were documented and examined for their progression-free (PFS) and overall survival (OS) significance. RESULTS A mean age of 6 (SD=2.7, range: 1-16) years was observed with general male dominance (M:F=1.69:1). Total serum lactate dehydrogenase (HR=2.04; 95% CI, 1.25-3.32; log rank=8.3; p=0.004), serum creatinine (HR=3.59; 95% CI, 1.62-7.98; log rank=15.4; p=0.002) and St. Jude stage (HR=1.74; 95% CI, 1.11-2.73; log rank=8.0; p=0.015) were important independent prognostic biochemical markers for both PFS and OS. Age, serum calcium, uric acid, potassium, sodium and phosphorus were non-prognostic. CONCLUSION The better monitoring of these prognostic indices coupled with risk-stratification treatment may improve patients' survival, especially in resource-limited settings.

Prognostic value of serum CD44, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 levels in patients with indolent non-Hodgkin lymphomas

Elevated serum CD44, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) have been linked to poor prognosis in aggressive lymphomas, but their utility in low grade lymphomas remains undefined. We evaluated serum CD44, VCAM-1 and ICAM-1 levels in 100 patients with newly diagnosed indolent NHL. The median pre-treatment values of the markers were as follows: CD44 540 ng/mL (range 156-1201), ICAM-1 311 ng/mL (range 102-1222) and VCAM-1 1165 ng/mL (range 248-4779). On univariate analysis, elevated sCD44, sICAM-1 and sVCAM-1 were significantly associated with worse overall (OS) and progression-free survival (PFS). In a subset analysis of patients with stage IV disease, the effects of sCD44 and sICAM-1 on OS persisted (p<0.05), as did the effect of sCD44 on PFS (p<0.01). In a multivariate analysis that included conventional prognostic factors and the Follicular Lymphoma International Prognostic Index (FLIPI) model, sICAM-1 demonstrated prognostic value for OS and PFS. We conclude that serum CD44, ICAM-1 and VCAM-1 can potentially be prognostic in patients with indolent NHL. Though the FLIPI model remains the gold standard for prognosis, these quantitative serologic markers may be useful as adjunct tools in assessing disease risk.

Prognostic tools in follicular lymphomas

Despite significant improvements in treatment modalities over the 10 years, the clinical course of patients with follicular lymphoma (FL) remains heterogeneous. Thus, prognostic indexes are still required to direct treatment choices and for the design of clinical trials. Investigators have conducted a variety of studies aimed at integrated assessment of biological and clinical features in order to identify novel prognostic factors and scoring systems. Genetic studies focused on tumor cells and the tumor microenvironment represent a step forward in understanding the biology of FL and are likely to provide new prognostic tools for future clinical use. Several prognostic factors have been identified and are currently used in combination to establish prognostic scores and to support therapeutic decisions. The FL International Prognostic Index (FLIPI) is currently used for defining individual risk of death. More recently, FLIPI2 was developed by the same group that built FLIPI as a new model for prognostic definition of patients with FL. The model was defined using prospectively collected data from patients who also received the monoclonal therapeutic antibody rituximab and stratifies patients into three risk categories for disease progression. Since many biological factors are not yet clinically validated or easily assessable, clinical data still represent the major source of prognostic information. The progressive development of new and more effective therapies for the treatment of FL makes the study of prognosis a dynamic and evolving area of clinical research.

Non-gastric marginal zone B-cell lymphoma in Korea: clinical features, treatment, and prognostic factors

Marginal zone B-cell lymphoma (MZL) is the second most common subtype of non-Hodgkin's lymphoma in Korea (17.3%). Mucosa-associated lymphoid tissue (MALT) can develop in almost any organ as a result of exposure to a persistent stimulus, such as chronic infection or certain autoimmune processes. Under conditions of prolonged lymphoid proliferation, a malignant clone may emerge, which is followed by the development of a MALT lymphoma. Whereas MALT lymphoma of the stomach is the most common and the most extensively studied, we focus on non-gastric MZL studies conducted in Korea that highlight the most recent advances with respect to MZL definition, etiology, clinical characteristics, natural history, treatment approaches, outcomes, and prognostic factors. Moreover, we discuss current organ-specific considerations and controversies, and identify areas for future research.

Follicular lymphoma prognostic factors in the modern era: what is clinically meaningful?

Follicular lymphomas (FL) account for 30% of non-Hodgkin's lymphomas (NHL). Their evolution is heterogeneous. Some patients present with indolent forms undergoing several relapses while in other patients the disease evolves abruptly toward aggressive NHL. This is why accurate prognostic indices are required so that treatment strategies may be optimized for each patient and so that trials may be conducted in groups of patients that are as homogeneous as possible. The Follicular Lymphoma International Prognostic Index (FLIPI) has been designed to separate patients into 3 groups with significantly different hazard ratios for death. Its accuracy has been confirmed in several studies. The FLIPI2 was designed more recently to separate patients with significantly different hazard ratios for progression/relapse in the era of anti-CD20 monoclonal antibody treatments. Gene profile studies have shown that the prognosis of FL is mainly related to the type, number, and activation of immune cells in the microenvironment of lymphomatous follicles. Immunohistochemical studies suggest that macrophages, CD4+ T cells and among them T-regulatory cells (T-regs) and programed death-1 cells (PD-1 cells) play a major role in the outcome of FLs. However, additional confirmatory studies are required due to discrepancies in results. Up to now, these biological study results are more useful for approaching the pathophysiology of FL rather than to be used as prognostic tools in clinical practice.

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.

The addition of oral idarubicin to a chlorambucil/dexamethasone combination has a significant impact on time to treatment failure but none on overall survival in patients with low grade non-Hodgkin's lymphoma: Results of the Scotland and Newcastle Lymphoma Group randomized NHL VIII trial

Two hundred untreated patients with low grade NHL (KIEL), including 155 follicular NHL, were randomized to six courses of treatment with chlorambucil 20 mg m-2 for 3 days and dexamethasone 4 mg bd for 5 days (CD) vs the same regimen plus oral idarubicin 10 mg m-2 for 3 days (CID). Responding patients could be randomized to no further treatment or maintenance treatment for up to 36 months with alpha interferon. Complete remissions/CRu were more frequent in the CID arm (35% vs 24%) but the overall response rate was similar; 87/91 (96%) vs 86/92 (93%). Overall survival (OS) did not differ between the two arms. Time to treatment failure (TTTF) was prolonged in the CID arm, p = 0.03; median time 28 vs 19 months. TTTF for the B-cell follicular group alone was for CID (77 patients) 33 months vs 18 months for CD (78 patients). Interferon conferred no apparent benefit. The Follicular Lymphoma International Prognostic Index (FLIPI) is confirmed as a good predictor of risk groups including a group of 23% with shorter survival. The addition of the oral anthracycline, idarubicin, led to a significant improvement in TTTF with low toxicity. The use of radiotherapy in this sub-group may have contributed to this result. CID is a potential for combination with antibody therapy particularly in older patient groups.

Prognostic factors for non-Hodgkin's lymphoma patients treated with chemotherapy may not predict outcome in patients treated with rituximab

Several factors predict outcome for patients with non-Hodgkin's lymphoma (NHL) after chemotherapy. However, predictors of response to rituximab have not been identified. Baseline characteristics for 166 NHL patients (130 follicular) in a phase III trial of rituximab were analysed by univariate and multivariate methods to determine whether any of 27 factors predict response and/or response duration. In a univariate analysis, response to rituximab was associated with follicular histology, no prior fludarabine therapy, prior autologous bone marrow transplantation (ABMT), lack of bone marrow involvement or extranodal disease, positive bcl-2 in blood, and fewer relapses. By univariate analysis, longer median time to progression (TTP) and/or duration of response (DR) after rituximab therapy was associated with International Prognostic Index lower-risk group, multiagent chemotherapy, and low/normal serum lactate dehydrogenase (LDH) or beta2 microglobulin. In the multivariate analysis, response to rituximab correlated with follicular histology, prior ABMT, multiagent chemotherapy, and no bone marrow involvement; longer TTP and/or DR correlated with low/normal serum LDH or beta2 microglobulin, high CD3+ cells, and response to last chemotherapy. The follicular lymphoma international prognostic index (FLIPI) did not correlate consistently with response to rituximab or response duration. Several factors associated with prognosis following chemotherapy did not correlate with response to rituximab or response duration. NHL patients can respond to rituximab despite having factors associated with a poor outcome to chemotherapy.

Follicular lymphoma: the case for timely intervention

After decades of slow progress in the management of follicular lymphoma (FL), important strides are occurring. An aim for cure is realistic and appropriate for some patients, including those with stage I-II disease, some histologic subtypes of FL (e.g., FL grade 3b) and even some relapsing patients following allogeneic stem cell transplantation approaches. Survival outcomes are improving, probably in large part related to the inclusion of anti-CD20 monoclonal antibodies in current treatment strategies.

Anti-idiotype antibody response after vaccination correlates with better overall survival in follicular lymphoma

Previous studies demonstrated that vaccination-induced tumor-specific immune response is associated with superior clinical outcome in patients with follicular lymphoma. Here, we investigated whether this positive correlation extends to overall survival (OS). We analyzed 91 untreated patients who received CVP chemotherapy (cyclophosphamide, vincristine, and prednisone) followed by idiotype vaccination. Idiotype proteins were produced either by the hybridoma method or by expression of recombinant idiotype-encoding sequences in mammalian or plant-based expression systems. We found that achieving a complete response/complete response unconfirmed (CR/CRu) to CVP and making an anti-idiotype antibody are 2 independent factors that each correlated with longer OS at 10 years (89% vs 68% with or without a CR/CRu, P = .024; 90% vs 69% with or without tumor-specific antibody production; P = .027). In the subset of patients who received hybridoma-generated vaccines, we found that anti-idiotype production was even more highly associated with superior OS (P < .002); this was the case even in patients with a partial response (PR) to CVP (P < .001).

Follicular lymphoma: clinical features and treatment

Follicular lymphoma (FL) is the second most common subtype of non-Hodgkin's lymphoma (NHL) in the Western world, constituting up to 22% of the total cases of NHL. This article describes the clinical characteristics of FL, its prognostic indicators, and its clinical course, including transformation to an aggressive lymphoma. Primary management and therapies for recurrent FL are detailed.

Follicular lymphomas

Follicular lymphomas constitute approximately 30% of all non-Hodgkin lymphomas. These lymphomas are characterized by at least partially follicular growth pattern, but diffuse areas may be present. The proportions of follicular or diffuse areas vary also from case to case, which seems to be associated with prognosis. Follicular lymphomas should not be divided into distinct subtypes, but rather shows a continuous gradation in the number of large cells. On the bases of this grading, three groups have been defined: grades 1-3. There is a consensus that grade 3 follicular lymphomas, namely grade 3b, should be discriminated from lower-grade cases. The cells of follicular lymphomas express surface immunoglobulin, more frequently IgM+/-IgD>IgG>IgA, B-cell-associated antigens, CD10+/-; they are CD5-, CD23-/+, CD43-, and CD11c-. Follicular lymphomas express bcl-2 proteins, which is useful in distinguishing reactive from neoplastic follicles. t(14;18) is present in 70-95% of follicular lymphomas, involving rearrangement of bcl-2 gene. Clinical behavior of follicular lymphomas is heterogeneous and differs according to the histologic grade and extension of disease. Moreover, the evaluation of these malignancies is conditioned by therapeutic decision, which is also determined by main prognostic factors. The International Prognostic Index for aggressive lymphomas is not optimal for follicular lymphomas. Conversely, the Italian Lymphoma Intergroup Index and, more recently, the Follicular Lymphoma International Prognostic Index (FLIPI), designed in pre-rituximab era, seem to correlate well with outcome. Several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with follicular lymphoma. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histologic grade, tumor burden, and risk-predicting factors.

Follicular lymphoma: today's treatments and tomorrow's targets

Over the past two decades, the incidence of follicular lymphoma has increased. Contemporary treatments include combinations of chemotherapy and monoclonal antibodies, radioimmunotherapy, new targeted agents and stem-cell transplantation. Prognostic tools are becoming more important in helping clinicians and patients decide on the most appropriate therapeutic regimens. Gene expression profiling and biomarkers are promising additions to this armamentarium. When patients do require therapy, the addition of rituximab to chemotherapy seems to improve remission duration and may improve overall survival. Radioimmunotherapy capitalises on the capacity to target radiation directly to malignant cells, and is currently approved for the treatment of relapsed/refractory follicular lymphoma. Further investigation is needed to clarify the role of stem-cell transplantation in follicular lymphoma. Only well-designed clinical trials can provide answers to the many questions that remain regarding the optimal treatment and sequence of treatments for patients with follicular lymphoma.

A single unit lymphoma experience: outcome in a Cape Town academic centre

To document outcome in Hodgkin and other lymphomas from a privately based academic centre the clinical records from 253 consecutive referrals were analysed. Diagnosis was according to World Health Organization criteria, prognosis assigned by the international index and therapy risk-stratified with results subject to appropriate statistical methodology. None of these patients underwent transplantation. For the cohort the median age was 55 years (range 11-94) and 63% were male. Constitutional symptoms were present in 22%; a quarter had previous chemotherapy and a third some form of irradiation prior to referral. Fifty-seven percent were stage I or II and 21% had nodal disease above and below the diaphragm whilst in the remainder cells were present in the circulation and this included the subset of chronic lymphocytic leukaemia -- small lymphocytic lymphoma. Positron emission scanning was not available for these studies. Median survival for the cohort is 3.2 years and reduced to 1.3 years by the presence of unexplained fever, sweating or inappropriate weight loss. Further adverse factors included any prior treatment, intermediate or high-grade histopathology, risk factors defined by the International Prognostic Index as well as late Rai stages. Analysed by disease category Hodgkin lymphoma (n=17) when managed according to the German Study Group protocols and hairy cell leukaemia (n=10) treated with two chlorodeoxyadenosine -- both had a stable plateau in excess of 90%. The corresponding figures for follicular variants (n=31) was 72% in the low risk and 58% in the remainder when treated with cyclophosphamide, vincristine and prednisone. Curves for the aggressive or diffuse large B-cell lymphoma (n=44) fell initially to 48%, but relapse continued in stages III and IV to the current level of 18% when receiving cyclophosphamide, hydroxydaunorubicin, vincristine and prednisone on the 21-day schedule. Chronic lymphocytic leukaemia -- small lymphocytic lymphoma (n=58) were initially given pulsed chlorambucil and sustained response was over 90% with low bulk, but declined to reach 30% as prognostic score rose. The miscellaneous categories (n<5 each) managed variably, but using the same criteria, were pooled and are presently at 62% and 30% for high and low grades. It is concluded that precise diagnosis, accurate staging and therapy on standardised risk-stratified programmes, delivered uniformly by a single multidisciplinary group, creates the all-important centre effect; matching figures are unlikely to apply outside these disciplined circumstances. The expectation from patients and referring physicians alike is that, since lymphomas are potentially curable, such an approach to comprehensive management will be regarded as standard even in an under resourced or Third World country. It follows that late referral and prior therapy will adversely affect performance status and compromise life span: These alternative approaches are inappropriate and strongly discouraged.

Do recent reports of prolonged survival in patients with follicular lymphoma suggest that deferral of therapy is no longer justifiable?

After an era in which it was unclear whether available systemic therapies for follicular lymphoma (FL) had influenced the survival of patients, several recent reports now suggest that survival of FL patients has improved over the past 25 years, presumably owing to expansion of therapeutic options. Has the pendulum swung so far that it is no longer justifiable to defer therapy in selected patients with FL? To date, the strongest evidence in support of treating all patients comes from randomized studies of different regimens suggesting that one offers a survival advantage over the other. The strongest evidence in support of deferring therapy for select patients comes from a few problematic randomized trials showing no difference between initial therapy and deferred therapy. The subset of patients with early-stage FL presents special but still inconclusive considerations. Accrual to prospective randomized trials is needed to answer the question.

Is the follicular lymphoma international prognostic index better than the international prognostic index to identify high-risk follicular lymphoma patients?

The aims of this study are to validate follicular lymphoma international prognostic index (FLIPI) prognostic score and to compare it with the international prognostic index (IPI) in a cohort of 57 Brazilian patients. According to IPI, 24 patients (42%) were in the low-risk, 28 (49%) in the intermediate-risk, and 4 (7%) in the high-risk group. The distribution according to FLIPI was: 20 (35%) in the low-risk, 8 (14%) in the intermediate-risk, and 29 (51%) in the high-risk group. According to IPI score, median OS was not reached for the low-risk, it was 45 months for the intermediate-risk and 25 months for the high-risk group (p < 0.001). When FLIPI score was applied, median OS was not reached for the low and intermediate-risk, and was 42 months for the high-risk group (p = 0.0064). These findings suggest that: (1) FLIPI score could be validated in a Brazilian population; (2) FLIPI is more accurate than IPI to identify FL patients having worse prognosis (51%); (3) IPI seems to be a better tool for clinical decisions because it selected a smaller high-risk group (7%) having worse prognosis. In our opinion, IPI high-risk patients are the real candidates for more aggressive therapies, avoiding unnecessary over-treatment.

The impact of Epstein-Barr virus status on clinical outcome in diffuse large B-cell lymphoma

To define prognostic impact of Epstein-Barr virus (EBV) infection in diffuse large B-cell lymphoma (DLBCL), we investigated EBV status in patients with DLBCL. In all, 380 slides from paraffin-embedded tissue were available for analysis by EBV-encoded RNA-1 (EBER) in situ hybridization, and 34 cases (9.0%) were identified as EBER-positive. EBER positivity was significantly associated with age greater than 60 years (P = .005), more advanced stage (P < .001), more than one extranodal involvement (P = .009), higher International Prognostic Index (IPI) risk group (P = .015), presence of B symptom (P = .004), and poorer outcome to initial treatment (P = .006). The EBER(+) patients with DLBCL demonstrated substantially poorer overall survival (EBER(+) vs EBER(-) 35.8 months [95% confidence interval (CI), 0-114.1 months] vs not reached, P = .026) and progression-free survival (EBER(+) vs EBER(-) 12.8 months [95% CI, 0-31.8 months] vs 35.8 months [95% CI, 0-114.1 months], respectively (P = .018). In nongerminal center B-cell-like subtype, EBER in situ hybridization positivity retained its statistical significance at the multivariate level (P = .045). Nongerminal center B-cell-like patients with DLBCL with EBER positivity showed substantially poorer overall survival with 2.9-fold (95% CI, 1.1-8.1) risk for death. Taken together, DLBCL patients with EBER in situ hybridization+ pursued more rapidly deteriorating clinical course with poorer treatment response, survival, and progression-free survival.

Predictive value of prognostic indices in patients with follicular lymphomas

PURPOSE

The aim of this study was to compare which of three indices--International Prognostic Index (IPI), Italian Lymphoma Intergroup (ILI) index, Follicular Lymphoma adapted International Prognostic Index (FLIPI)--is the most useful in predicting outcome in follicular lymphoma (FL) patients and to identify other clinical and laboratory prognostic factors that influence survival.

PATIENTS AND METHODS

Clinical and prognostic studies were carried out in 99 patients with FL.

RESULTS

The distribution of patients in IPI risk groups was 44.4%, 19.2%, and 36.4% of cases classified as low, intermediate, and high risk. According to ILI, low-, intermediate-, and high-risk scores were present in 34.3%; 27.3%, and 38.4% of FL patients. After applying the FLIPI index, the patients were divided into three risk groups: low (21.2% of cases), intermediate (39.4%), and high (39.4%) of FL patients. Survival curves demonstrated a high significant difference for the low- and high-risk group according to IPI and FLIPI (log rank=91.13 and 82.17 respectively; p < 0.0001). Difference in overall survival (OS) and failure-free survival (FFS) among low-, intermediate-, and high-risk groups according to ILI was statistically significant (log rank test p < 0.0001).

CONCLUSION

All three indices are important tools for prognostic evaluation of FL patients, as well as useful in identifying FL patients with poor outcome. IPI and FLIPI classify patients into two risk groups (low/intermediate- and high-risk groups) with significance difference in OS and FFS, but ILI is more reliable in stratifying patients in low-, intermediate-, and high-risk groups.

Clinical and molecular prognostic factors in follicular lymphoma

The observed variability in the clinical course of follicular lymphoma (FL), along with the diverse range of therapeutic options available, necessitates accurate prognostic stratification of the individual patient. A number of clinical, laboratory, and pathologic parameters have been associated with both good and poor risk disease; in some instances these have been incorporated into readily calculable prognostic indices. With new insights into disease biology and the resulting identification of biomarkers that have arisen from the analysis of both the genome and the transcriptome, more accurate individualization of prognosis will be realized. At present the clinical application of such biomarkers, however, remains largely in its infancy. This review examines the clinical and molecular prognostic features that have been identified as of value in FL.

Prolonged survival and low incidence of late toxic sequelae in advanced follicular lymphoma treated with a TBI-free autografting program: updated results of the multicenter consecutive GITMO trial

This study provides an updated report of the consecutive multicenter Gruppo Italiano Trapianto Midollo Osseo trial employing an intensified, purging-free, total body irradiation-free, high-dose sequential chemotherapy schedule with peripheral blood stem cell autograft (i-HDS) in advanced-stage follicular lymphoma (FL). Special interest has been devoted to late toxicities and outcome in terms of molecular status. Ninety-two untreated FL patients aged <or=60 were enrolled by 20 Italian centers and evaluated on an intention-to-treat basis. Main findings are as follows: (1) 5.5-years overall survival projection of 80% (median follow-up: 68 months), with no differences related to age-adjusted IPI score; (2) 46 (50%) of 92 patients presently in continuous complete remission; (3) projected long-term progression-free survival exceeding 80% for patients collecting PCR-negative stem cell harvests or achieving molecular remission within the first 2 years from the end of therapy; (4) actuarial 5-years risk of developing secondary myelodysplasia and acute myeloid leukemia of 3.7%, with most of these events occurring in patients re-treated for recurrent lymphoma. These results demonstrate that i-HDS is feasible, effective and safe even in terms of long-term outcome. As the HDS schedule can be easily supplemented with Rituximab, it is one of the best options for random comparison with Rituximab-supplemented conventional chemotherapy.

Prognosis of follicular lymphomas

Follicular lymphoma (FL) is as an indolent neoplasia with median survival measured in decades. Nevertheless, some patients have poor progression-free survival and overall survival. Several treatment approaches are proposed for patients with FL, however criteria to rationalize treatment decisions are lacking. Studies have been performed to build up prognostic indices that are useful for defining risk-adapted treatment recommendations. Available indices are based on parameters that have an independent role in predicting patient survival and that are variably correlated with the features of the disease, with the characteristics of the patient and with the effects of treatment. Two new prognostic indices have recently been proposed for FL: the Italian Lymphoma Intergroup (ILI) index and the Follicular Lymphoma International prognostic Index (FLIPI). Both indices are based on large series of patients and exhibit differences in their ability to discriminate between patients with different probabilities of survival. In recent years, with the advent of gene expression profile studies, our knowledge of the biology of FL is changing as novel data become available about the lymphoma cell and about the role of the microenvironment; these studies have already provided novel prognostic tools for identifying patients with more aggressive disease. Further data and large international cooperative studies are needed to translate into clinical practice the novel acquisitions of biology and therapeutics.

Case report: B-cell lymphoma of the maxillary sinus

The radiographic manifestation of malignant lesions of the maxillary sinus on dental radiographs may be nonspecific, making it difficult to differentiate the lesion from disease of odontogenic origin or more benign sinus pathoses. A radiopaque mass in the maxillary sinus, resulting from a malignant neoplasm growing within or extending into the sinus, can be easily confused with the mass of a mucous retention pseudocyst. Similarly, a malignant growth in the early stages of development can produce radiographic patterns in the alveolar process that may resemble inflammation of odontogenic origin. A case of B-cell lymphoma is reported. The lesion involved the maxillary alveolar process and sinus, producing such a radiographic pattern on the panoramic radiograph. Radiographic and clinical features that should be considered in establishing a differential diagnosis of malignant disease are discussed.

Current controversies in follicular lymphoma

Follicular lymphoma (FL) is characterized by its responsiveness to initial therapy, a pattern of repeated relapses, and a tendency for histologic progression to a process resembling diffuse, large B-cell lymphoma. Treatment decisions are complicated by the many effective options now available including combinations of conventional chemotherapy and monoclonal antibody, radioimmunotherapy, new targeted agents, and autologous and allogeneic stem cell transplantation. For selected patients, "watch and wait" or involved field irradiation may still be the most appropriate strategy. When therapy is required, a combination of rituximab and conventional chemotherapy results in improved outcomes compared to chemotherapy alone. Radioimmunotherapy alone or in combination with chemotherapy is an attractive strategy for patients with relapsed disease and may prove to be appropriate first line therapy. The role of stem cell transplant in FL requires further investigation. Novel agents with varied mechanisms of action continue to be developed. Enrollment of patients into clinical trials designed to address the many unanswered questions in FL is essential to improving clinical outcomes.