Subsets of Follicular Lymphoma (FL) 3B Have Divergent Biological Behavior and Clinical Outcome: Results from the Prospective Multicenter MER and LEO Cohorts
Background: FL3B is the least common among FL subtypes, accounting for 5-10% of cases. Almost half of FL3B tumors have concurrent diffuse large B cell lymphoma (DLBCL) in the diagnostic tissue biopsy, while FL3B rarely coexists with FL1-2 or FL3A. Several lines of evidence suggest that FL3B displays distinct biological and clinical characteristics resembling aggressive DLBCL rather than the indolent FL1-3A. Accordingly, DLBCL anthracycline-containing regimens, such as R-CHOP, are the mainstay of therapy for FL3B with or without coexisting DLBCL. However, while some studies show that R-CHOP therapy in FL3B was associated with 5-year overall survival (OS) rate of 54%, others report outcomes comparable to FL3A with 79-90% survival. Additional controversy involves the clinical implication of pure FL3B (FL3Bp) vs FL3B with concurrent DLBCL (FL3Bc). Thus, it remains unclear if FL3B clinically resembles DLBCL or lower-grade FL and whether FL3Bp has a different prognosis from FL3Bc. To address these questions, we performed a pooled study of two large prospective multicenter study cohorts to compare the clinical characteristics and outcomes of newly diagnosed FL3B with FL1-2, FL3A and DLBCL patients, all of whom were uniformly treated with frontline R-CHOP. Patients and Methods: Weevaluated 469 newly diagnosed patients with FL1-2 (n=216), FL3A (n=170) and FL3B (n=83) who received R-CHOP within 6 months of diagnosis and 739 de novo DLBCL (GCB n=455 and non-GCB n=284) who were prospectively enrolled into the Molecular Epidemiology Resource (MER) and the Lymphoma Epidemiology of Outcomes (LEO) cohorts between 2002 and 2021. FL3B cases were designated as FL3Bc and FL3Bp based on the presence or absence of coexisting DLBCL, respectively. Histologic diagnosis was determined by an expert pathologist at each participating center and centrally reviewed. Event free survival (EFS) and OS were defined as time from diagnosis to progression, relapse, retreatment or death, and early progression defined as failing to achieve EFS at 24 months (EFS24). Associations between clinical features and EFS or OS were evaluated using Kaplan Meier curves and Cox proportional hazards models unadjusted and adjusted for age and FLIPI (comparisons with FL1-2 and FL3A) or IPI (comparisons with DLBCL). Results: The median age was 61 years (range, 18-94 years). Among FL3B patients, 21 (25%) had FL3Bc and 62 (75%) FL3Bp. Baseline characteristics and outcomes were broadly similar between the two FL3B subtypes. We then compared all FL3B patients to those with lower-grade FL. Patients with FL3B showed similar clinical features to those with FL1-2 and FL3A, with exception for a lower tumor burden. After R-CHOP, FL1-2 patients had an inferior EFS (HR 2.13 95%CI 1.31-3.46) than those with FL3B, whereas there was no difference compared to FL3A. OS was similar across all FL grades. Although FL1-2 patients failed to achieve EFS24 more frequently than FL3B and FL3A (34% vs 18% and 15%, p<0.001), FL3B patients who did fail EFS24 had almost three folds higher risk of subsequent mortality (HR 2.84 95%CI 1.35-6.01) than other FLs. At 5-year follow-up, FL3B patients had twice the risk of relapse with an aggressive subtype (i.e., DLBCL, high-grade B-cell lymphoma) than those with FL1-2 and FL3A, who instead often recurred with indolent disease (i.e., FL1-2, FL3A; p<0.001). We further compared FL3B patients to those with DLBCL classified based on cell-of-origin into GCB and non-GCB subtypes. At diagnosis, patients with FL3B had more favorable clinical features than those with GCB and non-GCB DLBCL. Compared to FL3B, patients with non-GCB DLBCL had an inferior EFS (HR 1.73 95%CI 1.07-2.79) and OS (HR 2.04 95%CI 1.11-3.75), while those with GCB DLBCL did not show a significant difference in EFS (HR 1.41 95%CI 0.88-2.25) or OS (HR 1.69, 95%CI 0.93-3.06) likely due to insufficient statistical power. Patients with FL3B failed EFS24 less frequently than patients with GCB or non-GCB DLBCL (17% vs 25% and 32%; p=0.01). Among patients who failed EFS24, those with FL3B had a similar subsequent OS as both GCB (HR 1.41 95%CI 0.73-2.72) and non-GCB DLBCL (HR 1.27 95%CI 0.65-2.47). Conclusions: We report that FL3Bp and FL3Bc appear clinically similar. While most FL3B patients have a prognosis comparable to FL1-2 and FL3A, 18% exhibit aggressive behavior with poor outcome reminiscent of DLBCL. Future studies with a larger population will be needed to confirm our findings.
Outcomes in Early Relapse of Follicular Lymphoma Versus Early Histologic Transformation Following Firstline Immunochemotherapy in Follicular Lymphoma
Background: Approximately20% of patients with follicular lymphoma (FL) will experience disease progression or death within two years of years (POD24) of immunochemotherapy (IC) (Casulo et al, JCO 2015). A proportion of patients with POD24 have histologic transformation (HT), which heightens the risk of lymphoma-related death (Freeman et al, Blood 2019). To clarify the impact of HT on prognosis in POD24, we analyzed data from the Lymphoma Epidemiology of Outcomes (LEO) Consortium of Real-World Evidence (CReWE) to compare differences in outcomes among patients with POD24 with retained FL histology versus POD24 with HT. Methods: This was a multicenter study among 8 academic cancer centers. Eligible patients hadgrade 1-3a FL at diagnosis between 2003 and 2022, with POD24 following first line IC treatment with BR, R-CHOP, or R-CVP. POD24 was defined as disease recurrence within 24 months of IC. Patients with prior lines of treatment for FL were excluded. Patients with HT at first line IC were excluded. Biopsy at POD24 was obtained at the discretion of the treating physician. Three groups of POD24 were defined: POD24 with biopsy-proven retained FL histology (POD24_FL), POD24 with biopsy-proven HT to aggressive lymphoma (POD24_HT), and POD24 either without a biopsy or indeterminate histology on biopsy (POD24_I). We evaluated second-line treatments at time of POD24. Survival probabilities from second-line treatment initiation were estimated by the Kaplan-Meier method. Results A total of1,122 patients with FL were screened and308 patients with POD24 were identified.Median age at POD24 was 58 years (IQR 50-65).Among available data, race and ethnicity was reported as 76% non-Hispanic White, 3% non-Hispanic Black/African American, 9% Hispanic/Latino (any race), and 1% other minorities. First line therapy was R-CHOP in45% (140/308), BR in 33% (102/308) and R-CVP in 21% (66/308). Most patients (52%) had biopsy-proven retained FL at POD24 (162/308); 30% had no biopsy or indeterminate histology at POD24 (94/308), and 17% had biopsy-proven HT at POD24 (52/308). In the POD24_HT group, 52% received R-CHOP and 21% received intensive salvage chemotherapy as second line therapy. Patients with POD24_FL and POD24_I had similar rates of salvage chemotherapy (21% and 18%), BR (13% and 18%), R-CHOP (19% and 24%), and targeted therapies (8% and 5%), respectively, at second line. Consolidative autologous stem cell transplant was more common in POD24_HT patients at 21% versus 16% in POD24_FL and 6% in POD24_I. Patients with POD24_HT had significantly worse overall survival (OS) compared to POD24_FL (ref), with a hazard ratio of 3.79 (95% confidence interval [CI] 2.46-5.84), even after adjusting for age, FLIPI score, and first-line IC treatment. At 5 years, patients with POD24_HT had OS of 31% compared with an OS of 71% for patients with POD24_FL. Patients with POD24_I had similar outcomes to those with POD24_FL (5-year OS 75% versus 71%, respectively). Event-free survival (EFS) was also significantly lower in POD24_HT compared to POD24_FL: At 2 years, EFS was 27% for POD24_FL (21-35%) and 10% for POD24 _HT (4-23%). At 5 years, lymphoma remained the leading cause of death among patients with POD24, with 20% probability of lymphoma-related death in those with POD24_FL (95% CI 14.2-27.8) compared to 53% probability of lymphoma-related death in patients with POD24_HT (95% CI 40.6-70.7). Conclusions: In our multicenter cohort, we identified remarkable differences between the two biopsy-demonstrated entities of POD24 (i.e., with and without HT). Patients without a biopsy or indeterminate histology had similar outcomes as those with POD24_FL. Patients withearlyrelapse of FL after first-line IC remain a heterogeneous group with poor outcomes and a heightened risk of lymphoma-related mortality particularly compared with nonPOD24 groups. Even with retained FL histology, patients with POD24 had 20% probability of lymphoma-related death within 5 years of second-line treatment initiation. We demonstrate that poor survival is driven in part, but not entirely, by HT. Despite most patients receiving appropriate aggressive treatment, those with POD24_HT represent a distinctly vulnerable population warranting further study in directed prospective studies of both FL biology and clinical trials.
Understanding the Patient Perspective on Treatment Preferences for Follicular Lymphoma
Background: Due to recent advances, patients with follicular lymphoma (FL) have multiple treatment options with high response rates and durability. However, there is a gap in understanding how patient preferences influence treatment selection. To close this gap, we conducted a qualitative study using focus groups of adults with FL to understand their knowledge of treatment options, priorities, and decision-making process. We designed this study to inform the content of a planned discrete choice experiment in a larger population of patients with FL to better understand patient preferences and trade-offs around treatment delivery, side effects, outcomes, and quality of life. Methods: We conducted focus groups lasting 60-90 minutes, each with 3-5 participants recruited from the Lymphoma Epidemiology of Outcomes (LEO) Cohort Study. The LEO Cohort Study is a multi-institutional prospective cohort study of newly diagnosed adults with non-Hodgkin lymphoma from July 2015 to present. Each focus group was co-led by two investigators (U.D. and M.T.) and conducted using Zoom video technology. Participants were asked to comment on their understanding about FL and available treatments, their ideal treatment, their decision-making process about prior therapies, and quality of life and side effects associated with treatment. We performed exploratory content analysis of participant understanding of FL and their treatment preferences. We will continue to conduct focus groups until we reach thematic saturation, which we anticipate will occur with one additional focus group. Themes from all focus groups were identified and agreed upon by both investigators (U.D. and M.T.) and were verified by additional investigators (J.D., M.L, M.H., B.K.L, C.C., M.M.). Results: To date, we conducted five focus groups with a total of N=21 participants (median age 60 [range 41-88], 66.7% female, 71.4% non-Hispanic White, 14.3% Hispanic, 9.5% Asian, 4.8% Black/Hispanic). We identified the following themes and representative quotes: 1) Holistic approach:Participants wanted their oncologists to view their care from a holistic perspective, discussing their individual priorities and options that would accommodate their fitness routine and ability to work. “[I wish] if doctors can consider not just the physical choices, but also the mental and emotional choices as well, the holistic person.” - Participant 13 “There's zero chance I can go back to working in the type of career where other people rely on me for things. I can't keep things straight.” - Participant 16 2) Ideal treatment:An ideal treatment would limit impact on fatigue, cognitive function, and have minimal toxicity to preserve quality of life and an active lifestyle. “I would say something that has minimal impact on daily life would be ideal and something that would make you feel better.” - Participant 6 3) Shared decision-making: Participants wanted to be better informed about available treatment options and often utilized second opinions to inform their decisions. “It helped to get the second opinion versus not. It would've been a completely different set of events.” - Participant 17 4) Treatment burden:Financial impact and effort required by patients to receive care (e.g., travel, number of office visits, and duration of therapy) were key factors in patient decision-making. “Part of my quality of life went down because I had to fight with my insurance company consistently, and we pay a lot of money.” - Participant 11 “Really explain the time options and calendarize the treatment and be more specific about the amount of time that you're going to spend at the hospital and the process.” - Participant 20 5) Representation: Minority participants raised concerns about not knowing if the available treatment data pertained to them. “[My end-goal would be] having an understanding of how the treatment is going to be for minority people. Many times the treatments are tested, they are not tested for minorities.” - Participant 21 Conclusions: The patient perspective is critical for treatment decision-making and education. People living with FL expressed a desire for a holistic and individualized approach to treatment decision-making that incorporated their lifestyle, minimized side effects, and limited overall treatment burden. These focus groups identified emerging themes that warrant further investigation for survivors with FL.
Treatment patterns and outcomes in follicular lymphoma with POD24: an analysis from the LEO Consortium
Abstract Progression of disease within 24 months of initial immunochemotherapy (POD24) is a negative prognostic factor for patients with follicular lymphoma (FL). There is no standard treatment after POD24. Assembling an academic-based cohort from the Lymphoma Epidemiology of Outcomes Consortium for Real World Evidence, we evaluated patterns of care and outcomes for 220 patients with FL with POD24 and retained FL histology. Therapy after POD24 was heterogeneous, with no treatment category accounting for >25% of the total. Among patients initially treated with bendamustine-rituximab, rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) was the predominant second-line choice (48%). Among patients initially treated with R-CHOP, aggressive salvage therapy was the predominant second-line choice (38%). Overall response rate to therapy after POD24 was 64% (95% confidence interval [CI], 56-70); complete response rate was 39% (95% CI, 32-46). The median event-free survival for therapy after POD24 was 9.8 months (95% CI, 7.3-12.1); 5-year overall survival (OS) was 71% (95% CI, 65-78). OS was inferior for patients aged >70 years (hazard ratio [HR], 2.31; 95% CI, 1.27-4.20) and those with high-risk FL International Prognostic Index scores at diagnosis (HR, 2.10; 95% CI, 1.23-3.60). No treatment category stood out with more favorable results. Cause of death was predominantly lymphoma related. Patients with follicular histology at their POD24 event had a low cumulative incidence of transformation (1.1% at 5 years). Our study is among the largest cohorts describing contemporary patterns of care for patients with POD24, providing a focused data set useful for interpreting and designing prospective clinical trials in this population.
Transformation in marginal zone lymphoma: results from a prospective cohort and a meta-analysis of the literature
Abstract Marginal zone lymphoma (MZL) includes extranodal MZL (EMZL), splenic MZL (SMZL), and nodal MZL (NMZL) subtypes. Histologic transformation (HT) to large B-cell lymphomas is well documented but with a large variability in published cumulative incidence rates. We report results from the Molecular Epidemiology Resource (MER) cohort on the cumulative incidence of HT (with death as competing risk) and the associated risk factors and outcomes. We also conducted a meta-analysis of available studies on the cumulative incidence of HT. From 2002 to 2015, 529 patients with MZL were enrolled in the MER study (69% EMZL, 16% SMZL, and 15% NMZL). The 10-year overall survival (OS) from diagnosis was 66%. HT occurred in 21 patients with a 5-year and 10-year cumulative incidence of 2.7% (95% confidence interval [CI], 0.02-0.05) and 3.6% (95% CI, 0.02-0.06), respectively. HT was associated with an increased risk for death (subdistribution hazard ratio [HR], 3.95; 95% CI, 2.06-7.55). Predictors of HT were ≥2 extranodal sites and mucosa-associated lymphoid tissue International Prognostic Index score ≥2. The OS was 79% at 5 years and 55% at 10 years after HT. In the meta-analysis of 12 studies (6161 patients), the 5- and 10-year cumulative incidence of HT across all subtypes were 5% (95% CI, 0.05-0.06) and 8% (95% CI, 0.07-0.09), respectively. These rates were lower in EMZL (3% and 5%) than in SMZL (7% and 13%) and NMZL (9% and 13%). Although HT is relatively uncommon in the first decade after MZL diagnosis, it is associated with an inferior outcome and needs new approaches for prevention and management.
Real-world impact of differences in the WHO and ICC classifications of non-Hodgkin lymphoma: a LEO cohort study analysis
Abstract Recent introduction of 2 different lymphoma classifications has raised concerns about consistency in diagnosis, management, and clinical trial enrollment. Data from a large cohort reflecting real-world clinical practice suggest that differences between the classifications will affect <1% of non-Hodgkin lymphomas.
Transformation of marginal zone lymphoma to Hodgkin lymphoma
Abstract Underrepresentation of racial and ethnic subgroups in cancer clinical trials remains a persistent challenge. Restrictive clinical trial eligibility criteria have been shown to exacerbate this problem. We previously identified that up to 24% of patients treated with standard immunochemotherapy would have been excluded from recent first-line trials in diffuse large B-cell lymphoma (DLBCL) based on 5 laboratory-based criteria. These ineligible patients had worse clinical outcomes and increased deaths related to lymphoma progression, suggesting the potential exclusion of patients who could have benefited most from the novel therapies being evaluated. Using data from the prospectively enrolled Lymphoma Epidemiology Outcomes cohort study, with demographics broadly similar to the US patients diagnosed with lymphoma, we evaluated the impact of laboratory eligibility criteria from recent first-line DLBCL trials across various racial and ethnic backgrounds. There were significant differences in the baseline laboratory values by race/ethnicity with Black/African American (AA) patients having the lowest mean hemoglobin and highest creatinine clearance. Based on recent clinical trial eligibility criteria, AA and Hispanic patients had higher rates of laboratory-based ineligibility than non-Hispanic White patients. The largest gap in the clinical outcomes between eligible and noneligible patients was noted within AA patients with an overall survival hazard ratio based on POLARIX clinical trial criteria of 4.09 (95% confidence interval, 1.83-9.14). A thoughtful approach to the utility of each criterion and cutoffs for eligibility needs to be evaluated in the context of its differential impact across various racial/ethnic groups.
Abstract Patients with large B-cell lymphoma (LBCL) that fail to achieve a complete response (CR) or who relapse early after anthracycline-containing immunochemotherapy (IC) have a poor prognosis and are commonly considered to have “primary refractory disease.” However, different definitions of primary refractory disease are used in the literature and clinical practice. In this study, we examined variation in the time to relapse used to define refractory status and association with survival outcomes in patients with primary refractory LBCL in a single-center prospective cohort with validation in an independent multicenter cohort. Patients with newly diagnosed LBCL were enrolled in the Molecular Epidemiological Resource cohort (MER; N = 949) or the Lymphoma Epidemiology of Outcomes cohort (LEO; N = 2755) from September 2002 to May 2021. Primary refractory LBCL was defined as no response (stable disease [SD]) or progressive disease (PD) during, or by the end of, frontline (1L) IC (primary PD; PPD); partial response at end of treatment (EOT PR); or relapse within 3 to 12 months after achieving CR at EOT to 1L IC (early relapse). In the MER cohort, patients with PPD had inferior overall survival (OS; 2-year OS rate: 15% MER, 31% LEO) when compared with other subgroups considered in defining primary refractory disease, EOT PR (2-year OS rate: 38% MER, 50% LEO) and early relapse (2-year OS rate: 44% MER, 58% LEO). Among patients receiving 1L IC with curative intent, we identified that patients with PPD are the key subgroup with poor outcomes. We propose a definition of primary refractory LBCL as SD or PD during, or by the end of, 1L treatment.
The Lymphoma Epidemiology of Outcomes cohort study: Design, baseline characteristics, and early outcomes
AbstractTo address the current and long‐term unmet health needs of the growing population of non‐Hodgkin lymphoma (NHL) patients, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study (NCT02736357; https://leocohort.org/). A total of 7735 newly diagnosed patients aged 18 years and older with NHL were prospectively enrolled from 7/1/2015 to 5/31/2020 at 8 academic centers in the United States. The median age at diagnosis was 62 years (range, 18–99). Participants came from 49 US states and included 538 Black/African‐Americans (AA), 822 Hispanics (regardless of race), 3386 women, 716 age <40 years, and 1513 rural residents. At study baseline, we abstracted clinical, pathology, and treatment data; banked serum/plasma (N = 5883, 76.0%) and germline DNA (N = 5465, 70.7%); constructed tissue microarrays for four major NHL subtypes (N = 1189); and collected quality of life (N = 5281, 68.3%) and epidemiologic risk factor (N = 4489, 58.0%) data. Through August 2022, there were 1492 deaths. Compared to population‐based SEER data (2015–2019), LEO participants had a similar distribution of gender, AA race, Hispanic ethnicity, and NHL subtype, while LEO was underrepresented for patients who were Asian and aged 80 years and above. Observed overall survival rates for LEO at 1 and 2 years were similar to population‐based SEER rates for indolent B‐cell (follicular and marginal zone) and T‐cell lymphomas, but were 10%–15% higher than SEER rates for aggressive B‐cell subtypes (diffuse large B‐cell and mantle cell). The LEO cohort is a robust and comprehensive national resource to address the role of clinical, tumor, host genetic, epidemiologic, and other biologic factors in NHL prognosis and survivorship.