Prognostic factors in low-grade non-Hodgkin lymphomas

Factors associated with bone marrow involvement in lymphoma staging bone marrow examination: A South African single-centre retrospective study

Background: Accurate detection of bone marrow involvement (BMI) in lymphoma is important as it signifies stage 4 disease. Staging bone marrow examination (BME), therefore, influences treatment decisions and prognostication. The prevalence of BMI depends on multiple factors at presentation including lymphoma subtype, age, sex, human immunodeficiency virus (HIV) status and haematological parameters.Aim: To determine risk factors for BMI in lymphoma staging.Setting: The study was conducted in the department of haematological pathology, Tygerberg Hospital, Cape Town, South Africa.Methods: Retrospective cross-sectional descriptive study in adult patients, reviewing BMI and associated parameters, during their initial lymphoma staging procedure between 2016 and 2019.Results: Of a total of 387 lymphoma staging cases that were evaluated, 30.0% of them showed BMI. Diffuse large B-cell lymphoma, Hodgkin lymphoma and high-grade B-cell lymphoma were the most frequent subtypes diagnosed. The highest prevalence of BMI was in low-grade lymphomas. There was a statistically significant association between BMI and advanced age, pancytopenia and bicytopenia (anaemia with leucopenia, anaemia with thrombocytopenia or leucopenia with thrombocytopenia). Bicytopenia and pancytopenia showed high positive predictive values of BMI, respectively, 61.0% and 69.0%. Human immunodeficiency virus positivity (34.6%) was not predictive of BMI across all lymphoma subtypes. Normal blood counts had a high negative predictive value for BMI.Conclusion: BME remains an important part of lymphoma staging with 30.0% of all lymphomas showing BMI.

Prognostic Factors in Patients with Low-Grade Nonhodgkin Lymphoma

Low-grade Nonhodgkin lymphoma (LG-NHL) is characterized by indolent clinical course, which consist of marginal zone lymphoma (MZL), follicular lymphoma (FL), chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma, waldenstrom macroglobulinemia (WM) as the most common subtypes. Factors affecting prognosis and treatment need in these patients have long been the subject of research. A retrospective study was conducted with patients diagnosed with LG-NHL in Hematology Departments of two centres between 2010 and 2018. At the time of diagnosis, demographic and disease characteristics, hematological and biochemical parameters were examined. Using these data, treatment requirements, response and survival rates were calculated. The effect of parameters on survival and need to treatment were analyzed. 93 LG-NHL patients were included in this study. 40 (43%) of these patients were MZL, 28 (30.1%) were FL and 25 (26.8%) were others. In comparison of patients required treatment with patients without treatment, there was significant difference among the number of comorbidity, platelet count, neutrophil count, disease subgroups and ferritin levels. Logistic regression analysis revealed that disease subgroup (other than MZL and FL) and ferritin levels were independent risk factors for need to treatment. Only ferritin level was found to be associated with overall survival. The current study demonstrated an association between serum ferritin levels and prognosis in patients with LG-NHL. Given that it is easily available and low-cost, the initial ferritin level can be used as a prognostic marker for patients with indolent lymphoma.

Current role of FDG PET/CT in lymphoma

The management approach in Hodgkin's (HL) and high-grade non-Hodgkin's lymphomas (NHL) has shifted towards reducing the toxicity and long-term adverse effects associated with treatment while maintaining favorable outcomes in low-risk patients. The success of an individualized treatment strategy depends largely on accurate diagnostic tests both at staging and during therapy. In this regard, positron emission tomography (PET) using fluorodeoxyglucose (FDG) with computed tomography (CT) has proved effective as a metabolic imaging tool with compelling evidence supporting its superiority over conventional modalities, particularly in staging and early evaluation of response. Eventually, this modality was integrated into the routine staging and restaging algorithm of lymphomas. This review will summarize the data on the proven and potential utility of PET/CT imaging for staging, response assessment, and restaging, describing current limitations of this imaging modality.

Clinical significance of sIL-2R levels in B-cell lymphomas

Elevated soluble interleukin-2 receptor (sIL-2R) in sera is observed in patients with malignant lymphoma (ML). Therefore, sIL-2R is commonly used as a diagnostic and prognostic marker for ML, but the mechanisms responsible for the increase in sIL-2R levels in patients with B-cell lymphomas have not yet been elucidated. We first hypothesized that lymphoma cells expressing IL-2R and some proteinases such as matrix metalloproteinases (MMPs) in the tumor microenvironment can give rise to increased sIL-2R in sera. However, flow cytometric studies revealed that few lymphoma cells expressed IL-2R α chain (CD25) in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), and most CD25-expressing cells in the tumor were T-cells. Distinct correlations between CD25 expression on B-lymphoma cells and sIL-2R levels were not observed. We then confirmed that MMP-9 plays an important role in producing sIL-2R in functional studies. Immunohistochemical (IHC) analysis also revealed that MMP-9 is mainly derived from tumor-associated macrophages (TAMs). We therefore evaluated the number of CD68 and CD163 positive macrophages in the tumor microenvironment using IHC analysis. A positive correlation between the levels of sIL-2R in sera and the numbers of CD68 positive macrophages in the tumor microenvironment was confirmed in FL and extranodal DLBCL. These results may be useful in understanding the pathophysiology of B-cell lymphomas.

90Yttrium-Ibritumomab-Tiuxetan as First-Line Treatment for Follicular Lymphoma: 30 Months of Follow-Up Data From an International Multicenter Phase II Clinical Trial

Purpose

We report on a multicenter phase II trial of 90yttrium-ibritumomab-tiuxetan (90YIT) as first-line stand-alone therapy for patients with follicular lymphoma (FL).

Patients and Methods

Fifty-nine patients with CD20+ FL grade 1 to 3a in stages II, III, or IV, age 50 years old or older requiring therapy were enrolled. They received 90YIT according to standard procedure. If complete response (CR) or unconfirmed complete response (CRu) without evidence for minimal residual disease (MRD) 6 months after application of 90YIT was achieved, patients were observed without further intervention. The same applied to patients with partial response (PR) or with stable disease (SD). Patients with CR but with persisting MRD were to receive a consolidation treatment with rituximab. Primary end point was the clinical and molecular response rate. Secondary end points were time to progression, safety, and tolerability.

Results

Six months after treatment with 90YIT, 56% of the patients showed a CR or CRu and 31% achieved a PR. After a median follow-up of 30.6 months, the progression-free survival (PFS) was 26 months. There was a trend for shorter PFS in patients with increased lactate dehydrogenase (LDH). Of the 26 patients who had CR 12 months after 90YIT, only three had relapsed. Median time to next treatment has not been reached. The most common toxicities were transient thrombocytopenia and leukocytopenia. Nonhematologic toxicities never exceeded grade 2 according to Common Terminology Criteria for Adverse Events (CTCAE v2.0).

Conclusion

90YIT is well tolerated and achieves high response rates. Patients with increased LDH tend to relapse earlier, and individuals in remission 1 year after 90YIT appear to have long- lasting responses.

Therapeutic cancer vaccines: the latest advancement in targeted therapy

Therapeutic cancer vaccines represent an emerging therapeutic modality that may play a more prominent role in cancer treatment in the future. Therapeutic cancer vaccines are designed to generate a targeted, immune-mediated antitumor response. There are 2 main types of therapeutic vaccines: patient-specific (generated either from a patient's own cells or tumor) and patient- nonspecific, where a peptide- or vector-based vaccine induces an immune response in vivo against specific tumor-associated antigens. Studies are currently underway to investigate methods to enhance vaccine strategies, including combinations with standard anticancer therapies or immune-modulating agents. Cancer vaccines are usually well tolerated, with minimal toxicity compared with chemotherapy. This review summarizes selected therapeutic cancer vaccines in late clinical development.

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.