Response to low-dose involved-field radiotherapy in patients with non-Hodgkin's lymphoma

Two-year Outcomes of Ultra-low-dose Radiotherapy in the Treatment of Ocular Adnexal B-cell Lymphomas

BACKGROUND

This study focuses on the efficacy and 2-year outcomes of ultra-low-dose radiotherapy (RT) in treating primary and secondary ocular adnexal lymphoma (OAL).

METHODS

A retrospective analysis was conducted on patients with OAL between 2017 and 2022, treated with 4 Gy of RT. The primary and secondary outcomes assessed were response rate, progression-free survival, and lymphoma-related death.

RESULTS

Twenty-one patients with primary and secondary OAL of diverse, presentations, subtypes, and stages were included. The orbital tumors had an average size of 17 × 16 × 16 mm. Of the 14 primary OAL cases, 3 (14%) had T1N0M0 disease, 8 (38%) T2N0M0, and 3 (14%) T3N0M0 (AJCC 8th edition staging); of the 7 secondary OALs, 4 (19%) were stage IE, 2 (10%) stage IIE, and 1 (5%) stage IIIE (Ann Arbor staging). Ultra-low-dose RT yielded a 95% complete response rate and 100% progression-free survival rates, both locally and systemically at 2 years. Mild dry eyes were reported in 14% of patients as a late treatment toxicity.

CONCLUSIONS

Ultra-low-dose RT emerges as an effective and well-tolerated treatment approach for OAL. Our findings support the use of 4 Gy, showcasing high complete response rates (95%) and durable disease control without significant local relapses over an average follow up of 27 months. Our results align with earlier investigations, validating the curative potential of ultra-low-dose RT and reinforcing the concept of achieving favorable outcomes with minimal intervention. This approach may potentially alleviate the burden of long-term ocular side effects associated with higher radiation doses, enhancing the overall quality of life for OAL patients.

Multicenter phase II study of moderate low-dose radiotherapy in indolent non-Hodgkin lymphoma: CLCG-iNHL-01 protocol

Background: Radiotherapy is an effective treatment for indolent non-Hodgkin lymphoma (iNHL); however, the optimal radiotherapy dose remains to be determined. We hypothesize that a suitable dose may exist between 4 and 24 Gy. Methods: This prospective multicenter phase II trial intends to recruit 73 sites of iNHL patients, who will receive involved-site radiotherapy of 12 Gy in four fractions. The primary objective is the 6-month clinical complete response rate. Tumor tissue, blood and conjunctival specimens will be collected to identify potential predictive biomarkers. Discussion: The CLCG-iNHL-01 trial will evaluate the efficacy and toxicity of 12 Gy in patients with iNHL and provide information on a novel hypofractionation regimen of low-dose radiotherapy. Clinical Trial Registration: NCT05543070 (ClinicalTrials.gov).

Radiotherapy of Orbital and Ocular Adnexa Lymphoma: Literature Review and University of Catania Experience

Orbital and ocular adnexa lymphomas are rare neoplasms confined to the orbital region. The prognosis is generally favorable, with a high proportion of localized disease, indolent clinical course, prolonged disease-free intervals, and low lymphoma-related mortality rate. We report our experience on eleven patients with confirmed histological diagnosis of lymphoma stage IE-IIE, treated between 2010 and 2021 with radiotherapy alone or in association with chemotherapy or immunotherapy. Eight patients were treated with primary radiotherapy only, while three received previous systemic treatments. Six patients were treated with Proton beam therapy (PBT), and five with external beam radiotherapy (EBRT). The five-year local control rate was 98%; only one patient developed an out-of-field recurrence. We also conducted a comprehensive literature review using electronic databases (PubMed, EMBASE, and Cochrane Library). Articles were selected based on their pertinence to treatment of the ocular and adnexal lymphoma focusing on radiotherapy techniques (electron beam radiotherapy, photon beam radiotherapy, or proton beam radiotherapy), treatment total dose, fractionation schedule, early and late radio-induced toxicities, and patient's clinical outcome. Radiotherapy is an effective treatment option for orbital lymphoma, especially as standard treatment in the early stage of orbital lymphoma, with excellent local control rate and low rates of toxicity.

Personalised therapy in follicular lymphoma - is the dial turning?

Follicular lymphoma is the most common indolent lymphoma accounting for approximately 20%-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Whilst outcomes are mostly favorable, the spectrum of clinical phenotypes includes high-risk groups with significantly inferior outcomes. This review discusses recent updates in risk stratification and treatment approaches from upfront treatment for limited and advanced stage follicular lymphoma to the growing options for relapsed, refractory disease with perspectives on how to approach this from a personalized lens. Notable gaps remain on how one can precisely and prospectively select optimal treatment for patients based on varying risks, with an anticipation that an increased understanding of the biology of these different phenotypes and increasing refinement of imaging- and biomarker-based tools will, in time, allow these gaps to be closed.

Development of Organ-Preserving Radiation Therapy in Gastric Marginal Zone Lymphoma

Simple Summary

Gastric marginal zone lymphoma of the stomach is a rare cancer type primarily treated with oral proton pump inhibitors. If the disease does not respond to this, radiation is the treatment of choice. This review presents the development of radiation therapy over the last decades. Earlier, the stomach was surgically removed and irradiation was performed using large-field techniques and high doses of radiation. Currently, the standard treatment is the use of small-volume radiation therapy (with few side effects) with the preservation of the stomach, which provides excellent outcomes. In addition, this paper provides an outlook on current studies and possible future developments.

Abstract

Gastric marginal zone lymphoma (gMZL) of mucosa-associated lymphoid tissue (MALT) may persist even after H. pylori eradication, or it can be primarily Helicobacter pylori (H. pylori) independent. For patients without the successful eradication of lymphoma, or with progressive disease, treatment options have historically included partial or total gastrectomy. Presently, in these instances, curative radiation therapy (RT) is the current standard of care. This review emphasizes the historically changing role of radiation therapy in gMZL, progressing from large-volume RT without surgery, to localized RT, on its own, as a curative organ-preserving treatment. This overview shows the substantial progress in radiation therapy during the recent two to three decades, from high-dose, large-field techniques to low-dose, localized target volumes based on advanced imaging, three-dimensional treatment planning, and advanced treatment delivery techniques. RT has evolved from very large extended field techniques (EF) with prophylactic treatment of the whole abdomen and the supradiaphragmatic lymph nodes, applying doses between 30 and 50 Gy, to involved-field RT (IF), to the current internationally recommended involved site radiation therapy (ISRT) with a radiation dose of 24–30 Gy in gMZL. Stage-adapted RT is a highly effective and safe treatment with excellent overall survival rates and very rare acute or late treatment-related toxicities, as shown not only in retrospective studies, but also in large prospective multicenter studies, such as those conducted by the German Study Group on Gastrointestinal Lymphoma (DSGL). Further de-escalation of the radiation treatments with low-dose 20 Gy, as well as ultra-low-dose 4 Gy radiation therapy, is under investigation within ongoing prospective clinical trials of the International Lymphoma Radiation Oncology Group (ILROG) and of the German Lymphoma Alliance (GLA).

Excellent response to very-low-dose radiation (4 Gy) for indolent B-cell lymphomas: is 4 Gy suitable for curable patients?

Two doses of VLDRT at 2 Gy are associated with an impressive overall response rate of 90% across diverse indolent B-cell lymphomas.

Patients with early-stage, potentially[AQ4] curable disease had outcomes similar to those treated with 4 Gy as part of a novel RT strategy.

Radiotherapy plays an important role in managing highly radiosensitive, indolent non-Hodgkin lymphomas, such as follicular lymphoma and marginal zone lymphoma. Although the standard of care for localized indolent non-Hodgkin lymphomas remains 24 Gy, de-escalation to very-low-dose radiotherapy (VLDRT) of 4 Gy further reduces toxicities and duration of treatment. Use of VLDRT outside palliative indications remains controversial; however, we hypothesize that it may be sufficient for most lesions. We present the largest single-institution VLDRT experience of adult patients with follicular lymphoma or marginal zone lymphoma treated between 2005 and 2018 (299 lesions; 250 patients) using modern principles including positron emission tomography staging and involved site radiotherapy. Outcomes include best clinical or radiographic response between 1.5 and 6 months after VLDRT and cumulative incidence of local progression (LP) with death as the only competing risk. After VLDRT, the overall response rate was 90% for all treated sites, with 68% achieving complete response (CR). With a median follow-up of 2.4 years, the 2-year cumulative incidence of LP was 25% for the entire cohort and 9% after first-line treatment with VLDRT for potentially curable, localized disease. Lesion size >6 cm was associated with lower odds of attaining a CR and greater risk of LP. There was no suggestion of inferior outcomes for potentially curable lesions. Given the clinical versatility of VLDRT, we propose to implement a novel, incremental, adaptive involved site radiotherapy strategy in which patients will be treated initially with VLDRT, reserving full-dose treatment for those who are unable to attain a CR.

Low grade, indolent lymphomas of the head and neck: Comparative toxicity of standard versus very low dose radiation therapy

National Comprehensive Cancer Network guidelines recommend radiation therapy (RT) for localized indolent non-Hodgkin lymphomas (iNHL). Many referring physicians avoid RT to the head and neck (HN) due to fears of toxicity. Very low-dose radiation (4 Gy) for select patients produces sustained local control and recently gained popularity. We compared early and late toxicities of standard 24-30 Gy to 4 Gy in patients with HN iNHL. We retrospectively analyzed 266 consecutive patients with HN iNHL receiving RT from 1994 to 2017. Patient characteristics, outcomes, and toxicities were collected from medical records. Early (≤2 months post-RT) and late (>2 months post-RT) toxicities were graded per Common Terminology Criteria for Adverse Events version 4. Grades 1-2 were defined as "low-grade" and 3-4 "high-grade." Toxicity incidence was compared between 4 and >4 Gy, grouped by treated site (orbit, nonorbital head, neck, skin) and early versus late. Median follow-up was 23 months (2-145) and 68 months (2-256) for 4Gy and >4 Gy cohorts, respectively. Median dose for the >4 Gy cohort was 30 Gy (10.5-54 Gy). Early and late toxicity incidences were lower in the 4 Gy cohort compared to >4 Gy across all RT-sites: early toxicity, orbit, 42% versus 96%; nonorbital head, 24% versus 96%; neck, 22% versus 94%; skin, 31% versus 87%; late toxicity, orbit, 20% versus 71%; nonorbital head, 6% versus 66%; neck, 6% versus 57%; skin, 0% versus 46% (4 Gy vs. >4 Gy, respectively). Toxicities among both cohorts were largely low-grade. High-grade early and late toxicities did not occur in the 4 Gy cohort. There was 1 high-grade early toxicity (Grade 3 dry mouth) and 17 high-grade late toxicities (Grade 3 cataracts) in the >4 Gy cohort. RT to HN for iNHL is associated with minimal short- and long-term toxicity and excellent local control among 4 Gy and >4 Gy treatments. In this setting, "toxicity" concerns should not deter oncologists from potentially curative RT. In select patients where toxicity remains a concern, very low dose 4 Gy could be considered.

4 Gy versus 24 Gy radiotherapy for follicular and marginal zone lymphoma (FoRT): long-term follow-up of a multicentre, randomised, phase 3, non-inferiority trial

BACKGROUND

The optimal radiotherapy dose for indolent non-Hodgkin lymphoma is uncertain. We aimed to compare 24 Gy in 12 fractions (representing the standard of care) with 4 Gy in two fractions (low-dose radiation).

METHODS

FoRT (Follicular Radiotherapy Trial) is a randomised, multicentre, phase 3, non-inferiority trial at 43 study centres in the UK. We enrolled patients (aged >18 years) with indolent non-Hodgkin lymphoma who had histological confirmation of follicular lymphoma or marginal zone lymphoma requiring radical or palliative radiotherapy. No limit on performance status was stipulated, and previous chemotherapy or radiotherapy to another site was permitted. Radiotherapy target sites were randomly allocated (1:1) either 24 Gy in 12 fractions or 4 Gy in two fractions using minimisation and stratified by histology, treatment intent, and study centre. Randomisation was centralised through the Cancer Research UK and University College London Cancer Trials Centre. Patients, treating clinicians, and investigators were not masked to random assignments. The primary endpoint was time to local progression in the irradiated volume based on clinical and radiological evaluation and analysed on an intention-to-treat basis. The non-inferiority threshold aimed to exclude the chance that 4 Gy was more than 10% inferior to 24 Gy in terms of local control at 2 years (HR 1·37). Safety (in terms of adverse events) was analysed in patients who received any radiotherapy and who returned an adverse event form. FoRT is registered with ClinicalTrials.gov, NCT00310167, and the ISRCTN Registry, ISRCTN65687530, and this report represents the long-term follow-up.

FINDINGS

Between April 7, 2006, and June 8, 2011, 614 target sites in 548 patients were randomly assigned either 24 Gy in 12 fractions (n=299) or 4 Gy in two fractions (n=315). At a median follow-up of 73·8 months (IQR 61·9-88·0), 117 local progression events were recorded, 27 in the 24 Gy group and 90 in the 4 Gy group. The 2-year local progression-free rate was 94·1% (95% CI 90·6-96·4) after 24 Gy and 79·8% (74·8-83·9) after 4 Gy; corresponding rates at 5 years were 89·9% (85·5-93·1) after 24 Gy and 70·4% (64·7-75·4) after 4 Gy (hazard ratio 3·46, 95% CI 2·25-5·33; p<0·0001). The difference at 2 years remains outside the non-inferiority margin of 10% at -13·0% (95% CI -21·7 to -6·9). The most common events at week 12 were alopecia (19 [7%] of 287 sites with 24 Gy vs six [2%] of 301 sites with 4 Gy), dry mouth (11 [4%] vs five [2%]), fatigue (seven [2%] vs five [2%]), mucositis (seven [2%] vs three [1%]), and pain (seven [2%] vs two [1%]). No treatment-related deaths were reported.

INTERPRETATION

Our findings at 5 years show that the optimal radiotherapy dose for indolent lymphoma is 24 Gy in 12 fractions when durable local control is the aim of treatment.

FUNDING

Cancer Research UK.

Repeated courses of low-dose 2 × 2 Gy radiation therapy in patients with indolent B-cell non-Hodgkin lymphomas

Purpose

In patients with indolent B‐cell non‐Hodgkin's lymphoma (B‐NHL), one course of low‐dose radiotherapy (LD‐RT) 2 × 2 Gy is emerging as new option of therapy in palliative setting. Efficacy of LD‐RT when repeated remains to be determinate. This study aims to assess the efficacy of repeated LD‐RT given in patients with indolent B‐NHL.

Materials and Methods

All consecutive adult patients who received two or more courses of LD‐RT 2 × 2 Gy for indolent B‐NHL at Gustave Roussy institution, during the period 1990‐2015 were retrospectively investigated.

Results

Thirty‐three patients received two or more courses of LD‐RT for indolent B‐NHL during the study period. The median age was 57 (range 37‐80) years, histological types were distributed among follicular lymphoma (n = 24 pts; 73%), marginal‐zone lymphoma (n = 6 pts; 18%), and primary cutaneous follicle center lymphoma (n = 3 pts; 9%). The median number of low‐dose radiation therapy courses given per patients was 2 (range 2‐6). The overall response rates following the first and the second course of LD‐RT were 96% and 88%, respectively (P = .31). The 1‐ and 2‐years local control rates following the first courses of LD‐RT were 94% (CI 95: 86‐100) and 94% (CI 95: 86‐98); and were 91% (CI 95: 82‐100) and 88% (CI 95: 77‐100) following the second course of LD‐RT (P = .39).

Conclusion

The repeated courses of LD‐RT offered similar efficacy compare with the first course in patients with indolent B‐NHL. LD‐RT repeated is a simple, easy to give, and non‐toxic asset that could be investigated as treatment option in patients with indolent B‐NHL.

Radiotherapy in mantle cell lymphoma: A literature review

Mantle cell lymphoma (MCL) is a B-cell malignancy, comprising between 3% and 10% of all adult-onset non-Hodgkin lymphomas. MCL is considered incurable with current treatment modalities and most patients require multiple lines of treatment during their lifetime. MCL is very sensitive to radiotherapy (RT), even when delivered in low doses. In limited-stage MCL, RT can enable the de-escalation of systemic therapy. RT monotherapy is a valid option for frail patients. In advanced-stage disease, RT is very potent mode of palliation, even in heavily pretreated and chemo-resistant patients. Furthermore, it can provide a respite during which systemic treatment is unnecessary. In general, RT has a favorable toxicity profile and can be repeated as necessary for local relapse or distant disease. This effective, safe, and relatively inexpensive modality of therapy has been underutilized for patients with MCL. In this review, we will outline the use of RT for limited and advanced-stage disease and its potential application in combination with novel drugs.

Hematologic Malignancies

Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. The optimal radiation dose and target volume, and safe and effective ways of integrating radiation with systemic agents, vary depending on the histologic subtypes, stage at presentation, patient performance status, response to systemic therapy if given, treatment intent, and patient preferences. Limiting doses to surrounding organs without sacrificing disease control is of paramount importance. Reducing radiation doses and treatment volume in selected cases, and the use of advanced radiotherapy technology, can improve the therapeutic ratio of patients receiving radiation therapy for hematologic malignancies.

Priming radioimmunotherapy with external beam radiation in patients with relapsed low grade non-Hodgkin lymphoma

BACKGROUND

The aim of this study was to evaluate the outcomes of priming salvage radioimmunotherapy (RIT) with a low dose of external beam radiotherapy (EBRT) in patients with relapsed low grade non-Hodgkin lymphoma (LG-NHL).

METHODS

Patients who received salvage RIT with or without 2 × 2 Gy EBRT between March 2009 and February 2013 were retrospectively reviewed at a single institution. Planning target volume (PTV) for EBRT was created by adding a 1-2 cm expansion to the gross tumor volume depending on the anatomical location. Kaplan-Meier method via log-rank was employed to analyze the endpoints freedom from progression (FFP) and overall survival (OS).

RESULTS

We identified 22 patients who received salvage RIT without chemotherapy with a median follow up of 34 months. Of these, 9 (41%) patients were treated with EBRT immediately prior to RIT, and 13 (59%) received salvage RIT alone. Median FFP was not reached in patients who underwent combination treatment, while it was 9 months for patients treated with RIT alone (p = 0.02). OS for all patients at 36 months was 80.3% with no significant difference between the two groups (p = 0.88). On univariate analysis, the addition of EBRT was associated with improved FFP [hazard ratio (HR) = 4.17; 95% confidence interval (CI), 1.24-19.1; p = 0.02)]. No long term toxicities were reported in both groups.

CONCLUSIONS

RIT outcomes and effects were improved with addition of low-dose EBRT immediately prior to it, in the treatment of relapsed LG-NHL with no additional toxicity. This study is hypothesis-generating and the findings should be validated in prospective studies.

Low-dose radiation therapy (2 Gy × 2) in the treatment of orbital lymphoma

PURPOSE

Low-dose radiation has become increasingly used in the management of indolent non-Hodgkin lymphoma (NHL), but has not been studied specifically for cases of ocular adnexal involvement. The objective of this study is to investigate the effectiveness of low-dose radiation in the treatment of NHL of the ocular adnexa.

METHODS AND MATERIALS

We reviewed the records of 20 NHL patients with 27 sites of ocular adnexal involvement treated with low-dose radiation consisting of 2 successive fractions of 2 Gy at our institution between 2005 and 2011. The primary endpoint of this study is freedom from local relapse (FFLR).

RESULTS

At a median follow-up time of 26 months (range 7-92), the overall response rate for the 27 treated sites was 96%, with a complete response (CR) rate of 85% (n=23) and a partial response rate of 11% (n=3). Among all treated sites with CR, the 2-year FFLR was 100%, with no in-treatment field relapses. The 2-year freedom from regional relapse rate was 96% with 1 case of relapse within the ipsilateral orbit (outside of the treatment field). This patient underwent additional treatment with low-dose radiation of 4 Gy to the area of relapse achieving a CR and no evidence of disease at an additional 42 months of follow-up. Orbital radiation was well tolerated with only mild acute side effects (dry eye, conjunctivitis, transient periorbital edema) in 30% of treated sites without any reports of long-term toxicity.

CONCLUSIONS

Low-dose radiation with 2 Gy × 2 is effective and well tolerated in the treatment of indolent NHL of the ocular adnexa with high response rates and durable local control with the option of reirradiation in the case of locoregional relapse.

Radioimmunotherapy for B-cell non-hodgkin lymphomas

BACKGROUND

Radioimmunotherapy (RIT) is a safe and effective therapeutic option for patients with indolent B-cell non-Hodgkin lymphomas (NHL), in both up-front and relapsed/refractory settings. Two approved agents (90Y-ibritumomab tiuxetan and 131I-tositumomab) are available in the United States. Both target CD20 with similar clinical outcomes but with unique clinical considerations and radiation precautions due to the use of varying radioisotopes.

METHODS

This paper reviews the available evidence for these approved RIT agents and examines the recently published and ongoing clinical trials of potential novel indications for aggressive B-cell NHL.

RESULTS

A pretreatment biodistribution evaluation required before administering the 90Y-ibritumomab tiuxetan therapeutic dose has been removed, which once limited its usage. The potential clinical applications of RIT include relapsed/refractory indolent B-cell NHL, diffuse large B-cell lymphoma, indolent lymphoma in the front-line setting, and mantle cell lymphoma. Multiple novel RIT agents are in preclinical and clinical development, and the addition of radiosensitizers or external-beam radiotherapy may act in synergy with RIT for both indolent and aggressive lymphomas. The risk of treatment-related myelodysplastic syndrome does not appear to be higher in patients treated with RIT over those receiving chemotherapy alone.

CONCLUSIONS

RIT is a safe, effective, and significantly underutilized therapy for patients with B-cell NHL, and many studies have demonstrated the efficacy of 90Y-ibritumomab tiuxetan and 131I-tositumomab for relapsed/refractory indolent B-cell lymphomas. Continued research to establish its efficacy for other lymphoma subtypes is warranted.

Follicular lymphoma: 2012 update on diagnosis and management

DISEASE OVERVIEW

Follicular lymphoma (FL) is generally an indolent B-cell lymphoproliferative disorder of transformed follicular center B cells. FL is characterized by diffuse lymphoadenopathy, involvement of bone marrow, splenomegaly, and less commonly other extranodal sites of involvement. In general, cytopenias can occur but constitutional symptoms of fever, night sweats, and weight loss are uncommon.

DIAGNOSIS

Diagnosis is based on histology of preferably a biopsy of a lymph node. Immunohistochemical staining is positive in virtually all cases for cell surface CD19, CD20, CD10, and monoclonal immunoglobulin, as well as cytoplasmic expression of bcl-2 protein. The overwhelming majority of cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes.

RISK STRATIFICATION

The FL International Prognostic Index prognostic model for FL uses five independent predictors of inferior survival: age > 60 years, hemoglobin < 12 g/dL, serum lactate dehydrogenase > normal, Ann Arbor stage III/IV, number of involved nodal areas > 4. The presence of 0, 1, 2, and ≥ 3 adverse factors defines low, intermediate, and high-risk disease with median 10-year survivals in the pre-rituximab era of ~71, 51, and 36 months, respectively. With the use of more modern therapies, specifically anti-CD20 monoclonal antibody, the outcome has improved.

RISK-ADAPTED THERAPY

Observation continues to be adequate for asymptomatic patients with low bulk disease and no cytopenias. For patients needing therapy, most patients are treated with chemotherapy plus rituximab, which has improved response rates, duration of response, and overall survival. Randomized studies have shown additional benefit for maintenance rituximab both following chemotherapy-rituximab and single-agent rituximab. Autologous stem cell transplantation (SCT) has not shown a survival benefit in first remission patients. SCT including both autologous and allogeneic SCT or experimental agent therapy is considered for recurrent disease.

MicroRNA-148b enhances the radiosensitivity of non-Hodgkin's Lymphoma cells by promoting radiation-induced apoptosis

Growing evidence has demonstrated that microRNAs (miRNAs) play an important role in regulating cellular radiosensitivity. This study aimed to explore the role of miRNAs in non-Hodgkin's lymphoma (NHL) radiosensitivity. Microarray was employed to compare the miRNA expression profiles in B cell lymphoma cell line Raji before and after a 2-Gy dose of radiation. A total of 20 differentially expressed miRNAs were identified including 10 up-regulated and 10 down-regulated (defined as P < 0.05). Among the differentially expressed miRNAs, miR-148b was up-regulated 1.53-fold in response to radiation treatment. A quantitative real-time polymerase chain reaction (PCR) assay confirmed the up-regulation of miR-148b after radiation. Transient transfection experiments showed that miR-148b was up-regulated by miR-148b mimic and down-regulated by miR-148b inhibitor in the Raji cells. A proliferation assay showed that miR-148b could inhibit the proliferation of Raji cells before and after radiation. A clonogenic assay demonstrated that miR-148b sensitized Raji cells to radiotherapy. MiR-148b did not affect the cell cycle profile of post-radiation Raji cells compared with controls. An apoptosis assay showed that miR-148b enhanced apoptosis of Raji cells after irradiation. Taken together, these results demonstrate that miR-148b increased the radiosensitivity of NHL cells probably by promoting radiation-induced apoptosis, which suggests that miR-148b plays an important role in the response of NHL to ionizing radiation.

Fludarabine-containing chemotherapy for patients with previously untreated low-grade non-Hodgkin's lymphoma

BACKGROUND

The clinical efficacy and safety of fludarabine combination chemotherapy was investigated for the treatment of previously untreated patients with low-grade (NHL).

METHODS

Twenty-five patients who were newly diagnosed as low-grade NHL were treated with fludarabine combination chemotherapy. Fludarabine combination regimens consisted of fludarabine, mitoxantrone and dexamethasone or fludarabine, cyclophosphamide and mitoxantrone with or without rituximab and repeated every 4 weeks.

RESULTS

The median age was 60 years (range, 35-77 years), with 13 of 25 patients (52%) ≥60 years of age. Seven of 25 patients (28%) with an intermediate risk follicular lymphoma international prognostic index (FLIPI) and 9 of 25 patients (36%) with a high risk FLIPI were enrolled in this study. The delivered median number of chemotherapy was six (range, 2-9 cycles). The overall response rate with fludarabine-based treatment was 88%, including 52% complete remission and 36% partial remission. During the median follow-up of 19 months, the estimated 2-year event-free survival was 63±10% (95% CI, 43-83) and the 2-year overall survival was 78±9% (95% CI, 60-96). Fludarabine combination chemotherapy was frequently associated with grade 3 or 4 neutropenia in 84% patients. However, neutropenic infection was observed in only one (4%) patient. Four patients (16%) showed grade 3 or more non-hematologic toxicities, such as acute coronary syndrome, intracranial hemorrhage, anaphylaxis and gastric cancer.

CONCLUSION

Fludarabine-combination treatment was a highly active regimen with well toleration in untreated low-grade NHL.

Follicular lymphoma: 2011 update on diagnosis and management

DISEASE OVERVIEW

Follicular lymphoma (FL) is generally an indolent B-cell lymphoproliferative disorder of transformed follicular center B cells. FL is characterized by diffuse lymphoadenopathy, bone marrow involvement, splenomegaly, and less commonly other extranodal sites of involvement. In general, cytopenias can occur but constitutional symptoms of fever, nightsweats, and weight loss are uncommon.

DIAGNOSIS

Diagnosis is based on histology of preferably biopsy of a lymph node. Immunohistochemical staining is positive in virtually all cases for cell surface CD19, CD20, CD10 and monoclonal immunoglobulin, as well as cytoplasmic expression of bcl-2 protein. The overwhelming majority of cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes.

RISK STRATIFICATION

The Follicular Lymphoma International Prognostic Index prognostic model for FL uses five independent predictors of inferior survival: age > 60 years, hemoglobin <12 g/dL, serum LDH > normal, Ann Arbor stage III/IV, number of involved nodal areas > 4. The presence of 0-1, 2, and ≥3 adverse factors defines low, intermediate, and high-risk disease with median 10 year survivals in the pre-rituximab era of approximately 71, 51, and 36 months, respectively. With the use of more modern therapies, specifically anti-CD20 monoclonal antibody, the outcome has improved.

RISK-ADAPTED THERAPY

Observation continues to be adequate for asymptomatic patients with low bulk disease and no cytopenias. For patients needing therapy, most patients are treated with chemotherapy plus rituximab, which has improved response rates, duration of response, and overall survival. Randomized studies have shown additional benefit for maintenance rituximab both following chemotherapy-rituximab and single agent rituximab. Autologous stem cell transplantation has not shown a survival benefit in first remission patients. Stem cell transplantation (SCT) including both autologous and allogeneic SCT or experimental agent therapy is considered for recurrent disease.

Treatment of mucosa-associated lymphoid tissue lymphoma in Sjogren's syndrome: a retrospective clinical study

OBJECTIVE

To retrospectively analyze the clinical course of patients with mucosa-associated lymphoid tissue (MALT)-type lymphoma of the parotid gland and associated Sjögren's syndrome (SS).

METHODS

All consecutive patients with SS and MALT lymphoma (MALT-SS) diagnosed in the University Medical Center Groningen between January 1997 and January 2009 were analyzed. Clinical course and treatment outcome of SS and MALT lymphoma were evaluated.

RESULTS

From a total of 329 patients with SS, 35 MALT-SS patients were identified, with a median followup of 76 months (range 16-153 mo). MALT lymphoma was localized in the parotid gland in all cases. Treatment consisted of "watchful waiting" (n = 10), surgery (n = 3), radiotherapy (n = 1), surgery combined with radiotherapy (n = 2), rituximab only (n = 13), or rituximab combined with chemotherapy (n = 6). Complete response was observed in 14 patients, partial response in 1 patient, and stable disease in 20 patients. In 6 of 7 patients with initially high SS disease activity (M-protein, cryoglobulins, IgM rheumatoid factor > 100 KIU/l, severe extraglandular manifestations), MALT lymphoma progressed and/or SS disease activity increased after a median followup of 39 months (range 4-98 mo), necessitating retreatment. Only 1 patient with MALT who had low SS disease activity showed progression of lymphoma when left untreated.

CONCLUSION

An initially high SS disease activity likely constitutes an adverse prognostic factor for progression of lymphoma and/or SS. Such patients may require treatment for both MALT lymphoma and SS. In SS patients with localized asymptomatic MALT lymphoma and low SS disease activity, a "watchful waiting" strategy seems justified.

Reduced dose radiotherapy for local control in non-Hodgkin lymphoma: a randomised phase III trial

PURPOSE

This multicentre, prospective, randomised-controlled trial compared efficacy and toxicity of differing radiotherapy doses in non-Hodgkin lymphoma (NHL).

PATIENTS AND METHODS

Patients with any histological subtype of NHL, requiring radiotherapy for local disease control, whether radical, consolidative or palliative, were included. Three hundred and sixty one sites of indolent NHL (predominantly follicular NHL and marginal zone lymphoma) were randomised to receive 40-45Gy in 20-23 fractions or 24Gy in 12 fractions. Six hundred and forty sites of aggressive NHL (predominantly diffuse large B cell lymphoma as part of combined-modality therapy) were randomised to receive 40-45Gy in 20-23 fractions or 30Gy in 15 fractions. Patients with all stages of disease, having first-line and subsequent therapies were included; first presentations of early-stage disease predominated.

RESULTS

There was no difference in overall response rate (ORR) between standard and lower-dose arms. In the indolent group, ORR was 93% and 92%, respectively, (p=0.72); in the aggressive group, ORR was 91% in both arms (p=0.87). With a median follow-up of 5.6years, there was no significant difference detected in the rate of within-radiation field progression (HR=1.09, 95%CI=0.76-1.56, p=0.64 in the indolent group; HR=0.98, 95%CI=0.68-1.4, p=0.89 in the aggressive group). There was also no significant difference detected in the progression free or overall survival. There was a trend for reduced toxicities in the low-dose arms; only the reduction in reported erythema reached significance.

CONCLUSION

In a large, randomised trial, there was no loss of efficacy associated with radiotherapy doses of 24Gy in indolent NHL and 30Gy in aggressive NHL, compared with previous standard doses of 40-45Gy.