Molecular Diagnosis and Outcome Prediction in Diffuse Large B-Cell Lymphoma and Other Subtypes of Lymphoma

Epidemiologic and Clinical Patterns of Malignant Lymphoma in Qatar 2013-2017: A Population-Based Cohort Study

INTRODUCTION

Lymphoma, encompassing common non-Hodgkin lymphoma (NHL) and less common Hodgkin lymphoma (HL), represents significant hematological malignancies. Advancements in treatment modalities have reshaped survival rates, particularly in NHL. This complexity results in varying outcomes, some requiring extended observation periods and multiple chemotherapy treatments. The primary objective was to explore and compare the overall survival (OS) of HL and NHL at 1, 3, and 5-year follow-ups among adult lymphoma patients in Qatar during January 2013-December 2017. Further objectives encompass comparing the most prevalent histological types, clinical and epidemiological traits of HL and NHL, as well as secondary aims of assessing clinical features, treatment, response, disease-free survival, and OS.

METHODS

A retrospective, descriptive study of consecutive cases was conducted at Qatar's NCCCR between 2013 and 2017. Inclusion criteria involved patients ≥18 years old, of any gender and clinical stage at diagnosis, who received chemotherapy and had known outcomes. Descriptive statistics were applied, and survival analysis utilized Kaplan-Meier curves. STATA version 13.0 facilitated data analysis.

RESULTS

Between 2013 and 2017, 414 individuals in Qatar were diagnosed with lymphoma. The median age at diagnosis was 49 years (IQR 36-95 years; p < 0.001) across all patients. Males exhibited a higher likelihood of developing HL and NHL, comprising 74% and 70% of cases, respectively, though this difference was statistically insignificant (p = 0.45). Among NHL-B subtypes, mature B-cell neoplasms (60%) predominated, while lymphocyte-rich subtype (49%) was prominent in HL cases. With a median follow-up of 17.3 months, OS rates at 1, 3, and 5 years were 99%, 82%, and 64%, respectively for all lymphoma patients. Subtype stratification revealed trends in 3-year follow-up OS (94 vs. 82%) for HL and NHL, with 5-year OS of 67% and 60%, respectively. HL demonstrated higher OS throughout the study period compared to NHL (p < 0.001), though median OS remained unreached.

CONCLUSIONS

Diffuse large B-cell lymphoma emerged as the most prevalent subtype among lymphomas in Qatar. Generally, HL exhibited superior survival rates, at 67% compared to 60% for NHL. Minor deflation in survival rates, particularly for HL, might be attributed to Qatar's immigration patterns.

Results of a multicentre UK-wide retrospective study evaluating the efficacy of pixantrone in relapsed, refractory diffuse large B cell lymphoma

Relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in those unfit or ineligible for autologous stem cell transplantation is associated with a poor outcome and new treatment approaches are needed. Pixantrone is a novel aza-anthracenedione which is structurally similar to anthracyclines and is licenced in R/R DLBCL and National Institute for Health and Care Excellence (NICE)-approved following the PIX301 trial. No data exist post-NICE approval. We performed a UK-wide retrospective multi-centre study of 92 R/R DLBCL who received pixantrone. Eighty-five per cent had refractory disease and 72% had an international prognostic index (IPI) 3-5 at commencement of pixantrone. The median progression-free survival (PFS) was 2·0 months (95% confidence interval (CI) 1·5-2·4) and the median overall survival was 3·4 months (95% CI 2·7-4·5). The overall response rate was 24% (complete response 10%; partial response 14%). We demonstrate that pixantrone has limited activity in a cohort of high risk, predominantly refractory DLBCL. Multivariate Cox regression revealed that patients who relapsed >12 months after first line treatment, those with fewer prior lines of therapy and relapsed (non-refractory) DLBCL had improved PFS. The major population of unmet need are those with refractory DLBCL who are poorly represented within trials and in whom pixantrone appears less efficacious compared to relapsed DLBCL.

Personalized medicine: marking a new epoch in cancer patient management

Personalized medicine (PM) is defined as "a form of medicine that uses information about a person's genes, proteins, and environment to prevent, diagnose, and treat disease." The promise of PM has been on us for years. The suite of clinical applications of PM in cancer is broad, encompassing screening, diagnosis, prognosis, prediction of treatment efficacy, patient follow-up after surgery for early detection of recurrence, and the stratification of patients into cancer subgroup categories, allowing for individualized therapy. PM aims to eliminate the "one size fits all" model of medicine, which has centered on reaction to disease based on average responses to care. By dividing patients into unique cancer subgroups, treatment and follow-up can be tailored for each individual according to disease aggressiveness and the ability to respond to a certain treatment. PM is also shifting the emphasis of patient management from primary patient care to prevention and early intervention for high-risk individuals. In addition to classic single molecular markers, high-throughput approaches can be used for PM including whole genome sequencing, single-nucleotide polymorphism analysis, microarray analysis, and mass spectrometry. A common trend among these tools is their ability to analyze many targets simultaneously, thus increasing the sensitivity, specificity, and accuracy of biomarker discovery. Certain challenges need to be addressed in our transition to PM including assessment of cost, test standardization, and ethical issues. It is clear that PM will gradually continue to be incorporated into cancer patient management and will have a significant impact on our health care in the future.

The WHO classification of lymphomas: cost-effective immunohistochemistry using a deductive reasoning "decision tree" approach: part II: the decision tree approach: diffuse patterns of proliferation in lymph nodes

The 2008 World Health Organization Classification of Tumors of the Haematopoietic and Lymphoid Tissues defines current standards of practice for the diagnosis and classification of malignant lymphomas and related entities. More than 50 different types of lymphomas are described. Faced with such a broad range of different lymphomas, some encountered only rarely, and a rapidly growing armamentarium of 80 or more pertinent immunohistochemical (IHC) "stains," the challenge to the pathologist is to use IHC in an efficient manner to arrive at an assured and timely diagnosis. This review uses deductive reasoning following a decision tree or dendrogram model, combining basic morphologic patterns and common IHC markers to classify node-based malignancies by the World Health Organization schema. The review is divided into 2 parts, the first addressing those lymphomas that produce a follicular or nodular pattern of lymph nodal involvement appeared in the previous issue of AIMM. The second part addresses diffuse proliferations in lymph nodes. Emphasis is given to the more common lymphomas and the more commonly available IHC "stains" for a pragmatic and practical approach that is both broadly feasible and cost-effective. By this method, an assured diagnosis may be reached in the majority of nodal lymphomas, at the same time developing a sufficiency of data to recognize those rare or atypical cases that require referral to a specialized center.

Pathophysiology of retinal lymphoma

Retinal lymphoma, the most common form of intraocular lymphoma, is a high-grade malignancy, usually of B-cell type, and is associated with a poor prognosis because of frequent central nervous system (CNS) involvement. The neoplastic B-cells of retinal lymphoma have a characteristic morphology and immunophenotype, express certain chemokines and chemokine receptors, and produce interleukins (IL), e.g. IL-10. Together with the cytological features of these tumors, the immunophenotype, presence of immunoglobulin rearrangements, and biochemical profile aid the diagnosis of retinal lymphomas. Immunophenotyping and somatic mutation analysis suggest derivation of most retinal lymphomas from an early post-germinal centre B-cell. Chromosomal translocation data would suggest, however, that a subgroup of these neoplasms may arise from germinal centre B-cells, and these could be associated with a better prognosis. Further investigations, such as gene expression profiling, are required to identify oncogenic pathways potentially involved in retinal lymphoma development, and to identify new prognostic/therapeutic markers for this tumor.

The critical role of histology in an era of genomics and proteomics: a commentary and reflection

The role of histologic examination in lymphoma diagnosis has been called into question by proponents of new technologies, such as genomics and proteomics. We review the history and salient features of morphologic evaluation in lymphoid diseases, and discuss the general and specific limitations of mature ancillary techniques, such as immunohistochemistry, flow cytometry, and molecular studies. We then speculate on the future relationship between morphology and the new genomic and proteomic technologies as they become integrated into clinical practice.

Grading of follicular lymphoma using flow cytometry

BACKGROUND

The treatment and prognosis of follicular lymphoma (FL) is dependant on the grade of the disease. In the World Health Organization classification of lymphoma, grading of FL into low grade (1 and 2) and high grade (3) is recommended. Grading of FL is possible in excision biopsy; histological grading is subjective and inconsistent. Grading is extremely difficult in needle core biopsies and fine needle aspirates. We attempted to grade FL using flow cytometry (FCM) and CD19/ forward scatter.

MATERIALS AND METHODS

Cases of FL seen in our institution and submitted for FCM were evaluated for the percentage of cells detected beyond the 500-channel mark (on a 1024 scale) on a CD19/forward scatter dot plot. We hypothesized that these cells most likely represent centroblasts and their percentage would reflect the grade of the disease. Histological grading of the lymphoma on the open biopsies constituted the reference for FL grade.

RESULTS

Thirty-six cases of FL, including 22 males and 14 females, ranging in age from 19 to 92 years (median, 42 years), were studied. There were 17 cases of low grade (grade 1; n=10 and grade 2; n=7) and 19 cases of high grade (grade 3) FL. The percentage of cells identified beyond the 500-channel mark on CD19/forward scatter dot plot ranged from 0.12% to 12.55% (median, 4.9%) in low grade (grade 1 and 2) whereas the percentage of those cells in high grade FL ranged from 6.22% to 51.95% (median, 21%; P=0.00001).

CONCLUSION

Our findings suggest that using a CD19/forward scatter dot plot can help identify centroblasts in FL making grading possible on FCM, especially in small biopsies and fine needle aspirates.

Recent advances in the molecular diagnosis of diffuse large B-cell lymphoma

The field of molecular diagnostics is changing and adapting to new information obtained from genetic, genomic and proteomic profiling of diseases. One of the novel technologies that has made significant impact on the molecular diagnosis of lymphoid malignancies is DNA microarray technology. It has allowed the profiling of the most common types of lymphomas, identifying distinct molecular signatures of these diseases as well as novel subtypes that cannot otherwise be identified by conventional methods. In addition, it has also allowed the construction of molecularly defined prognostic models for various types of lymphomas and to better understand the molecular mechanisms that determine the behavior of the tumor. In this review, recent advances in the molecular diagnosis of diffuse large B-cell lymphoma are highlighted, using examples of how gene expression profiling has been used in disease classification and outcome predictions. The future development of this field and its applications in the clinical arena will also be discussed.

B Cell Lymphoma: A Case With Localized Involvement of the Prostate on F-18-FDG Examination

An 80-year-old man had symptoms of urinary retention. Biopsy of the prostate revealed B cell lymphoma. To evaluate the extent of the disease, an F-18 FDG study was performed with positron emission tomography/computed tomography (CT). One hour after intravenous administration of 18.5 mCi F-18 FDG, imaging was carried out from the skull base to the upper thigh. An area of moderately increased activity was noted within the prostate bed. A noncontrast CT, for attenuation correction and anatomic localization, revealed maintenance of fat planes around the prostate, indicating disease localized to that organ. Hence, a B cell lymphoma had been localized to the prostate.

Discovery and development of biomarkers of neurological disease

The identification of clinically relevant biomarkers for neurological diseases poses unique challenges. These include an historical lack of availability of relevant tissues from the site of pathology, relatively poorly matured techniques for disease diagnosis, the complexity and cellular heterogeneity of the brain, and a clear deficiency of models for functional validation of candidate biomarkers. Here, the unique challenges that neurological disorders introduce to biomarker discovery are described and how modern technological advances in genomics, proteomics and metabolomics are overcoming these obstacles and are driving the discovery of novel biomarkers to improve early diagnosis and therapeutic treatment is discussed.

Aggressive B-cell lymphomas: a review based on the workshop of the XI Meeting of the European Association for Haematopathology

The generic term aggressive B-cell lymphoma includes a variety of entities, each with particular diagnostic and therapeutic issues. To define these entities better and to help confront such issues, a workshop was organized by the European Association of Haematopathology (EAHP) and the Society of Haematology during the XI Meeting of the EAHP, held in Italy in May 2002. Participants were asked to submit cases under various categories and all cases submitted were examined and reviewed by the panel members. The panel's diagnoses formed the basis for discussion at the workshop and a limited number of cases were selected to be presented in more detail and discussed during the workshop. After the workshop the panel met again to discuss the outcome, summarized in this report, which describes the panel's proposals regarding diagnostic criteria, terminology, the definition of new entities and evaluation of biological differential and new prognostic parameters.