Evolving role of radiation therapy for hematologic malignancies

The art of war: using genetic insights to understand and harness radiation sensitivity in hematologic malignancies

It is well established that hematologic malignancies are often considerably radiosensitive, which enables usage of far lower doses of therapeutic radiotherapy. This review summarizes the currently known genomic landscape of hematologic malignancies, particularly as it relates to radiosensitivity and the field of radiation oncology. By tracing the historical development of the modern understanding of radiosensitivity, we focus on the discovery and implications of pivotal mutated genes in hematologic malignancies such as TP53, ATM, and other genes critical to DNA repair pathways. These genetic insights have contributed significantly to the advancement of personalized medicine, aiming to enhance treatment precision and outcomes, and there is an opportunity to extend these insights to personalized radiotherapy. We explore the transition from early discoveries to the current efforts in integrating comprehensive genomic data into clinical practice. Specific examples from Hodgkin lymphoma, non-Hodgkin lymphoma, and plasma cell neoplasms illustrate how genetic mutations could influence radiosensitivity and impact subsequent radiotherapeutic response. Despite the advancements, challenges remain in translating these genetic insights into routine clinical practice, particularly due to the heterogeneity of alterations and the complex interactions within cancer signaling pathways. We emphasize the potential of radiogenomics to address these challenges by identifying genetic markers that predict radiotherapy response and toxicity, thereby refining treatment strategies. The need for robust decision support systems, standardized protocols, and ongoing education for healthcare providers is critical to the successful integration of genomic data into radiation therapy. As research continues to validate genetic markers and explore novel therapeutic combinations, the promise of personalized radiotherapy becomes increasingly attainable, offering the potential to significantly improve outcomes for patients with hematologic malignancies.

FoxO1 regulates human haematopoietic stem cells self-renewal and engraftment

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is one of the most effective ways to treat hematological malignant diseases, but the traditional culture of hematopoietic stem cells (HSCs) in vitro will soon lose their ability to self-renewal or differentiate into multilineage blood cells.

METHODS

To determine whether Forkhead boxO1 (FoxO1) is implicated in the development of HSCs, lentiviral vectors expressing knockdown (KD) or overexpression (OE) of FoxO1 were utilized in fetal liver-derived hematopoietic stem and progenitor cells (FL-HSPCs). The impacts on the proliferation and hematopoietic differentiation of FL-HSPCs were subsequently evaluated via flow cytometry (FCM). Furthermore, the effect of FoxO1-OE on the self-renewal of cord blood-derived hematopoietic stem and progenitor cells (CB-HSPCs) was investigated. Additionally, the transplantation ability of hematopoietic stem cells derived from these CB-HSPCs in mice after secondary transplantation was also assessed by FCM.

RESULT

After knocking down FoxO1 in FL-HSPCs, the apoptosis rate was significantly increased, and the expression of hCD45 was significantly decreased. Conversely, overexpression of FoxO1 reversed this phenomenon, effectively promoting the expansion and differentiation of FL-HSPCs in vitro. Similarly, it was found that FoxO1-OE could effectively enhance the expansion of CB-HSPCs. Furthermore, upon transplantation of CB-HSPCs overexpressing FoxO1 into NSG mice, multilineage human hematopoietic reconstruction was promoted. Notably, the results of secondary transplantation revealed that only the FoxO1-OE group exhibited multilineage reconstitution.

CONCLUSION

In conclusion, our study confirmed that FoxO1-OE could enhance the self-renewal and engraftment of CB-HSPCs.

Comparative Analysis of Dosimetry: IMRT versus 3DCRT in Left-Sided Breast Cancer Patients with Considering Some Organs in Out - of - Field Borders

Purpose

The local management approach for node-positive breast cancer has undergone substantial evolution. Consequently, there exists a pressing need to enhance our treatment strategies by placing greater emphasis on planning and dosimetric factors, given the availability of more conformal techniques and delineation criteria, achieving optimal goals of radiotherapy treatment. The primary aim of this article is to discuss how the extent of regional nodal coverage influences the choice between IMRT and 3D radiation therapy for patients.

Patients and Methods

A total of 15 patients diagnosed with left breast cancer with disease involved lymph nodes were included in this study. Delivering the recommended dose required the use of a linear accelerator (LINAC) with photon beams energy of 6 mega voltage (6MV). Each patient had full breast radiation using two planning procedures: intensity-modulated radiotherapy (IMRT) and three-dimensional radiotherapy (3D conformal). Following the guidelines set forth by the Radiation Therapy Oncology Group (RTOG), the planned treatment coverage was carefully designed to fall between 95% and 107% of the recommended dose. Additionally, Dose Volume Histograms (DVHs) were generated the dose distribution within these anatomical contours.

Results and Conclusion

The DVH parameters were subjected to a comparative analysis, focusing on the doses absorbed by both Organs at Risk (OARs) and the Planning Target Volume (PTV). The findings suggest that low doses in IMRT plan might raise the risk of adverse oncological outcomes or potentially result in an increased incidence of subsequent malignancies. Consequently, the adoption of inverse IMRT remains limited, and the decision to opt for this therapy should be reserved for situations where it is genuinely necessary to uphold a satisfactory quality of life. Additionally, this approach helps in reducing the likelihood of developing thyroid problems and mitigates the risk of injuries to the supraclavicular area and the proximal head of the humerus bone.

New progress in an old debate? Applying the DSM-5 criteria to assess traumatic events and stressor-related disorders in cancer survivors

OBJECTIVE

The rather broad definition of medical trauma within DSM-IV has contributed to long-lasting debates on the applicability of Posttraumatic Stress Disorder (PTSD) in oncological patients and its differentiation from Adjustment Disorder (AjD) which results from non-traumatic critical life events. The DSM-5 criteria have introduced a narrower definition of medical traumatization. However, studies on updated prevalence rates in cancer patients are missing.

METHODS

Within a cross-sectional study, we assessed hematological cancer survivors using the Structured Clinical Interview for DSM-5. We investigated (i) the frequency and type of cancer-related stressors, (ii) the proportion of stressors qualifying as traumatic according to DSM-5 (i.e., an event of sudden and catastrophic character) and (iii) the prevalence of PTSD, AjD and cancer-related PTSD according to DSM-5.

RESULTS

291 patients participated (response rate: 58%). Mean age was 54 years, 60% were male. 168 patients (59%) reported cancer-related stressors, with the most frequent being cancer diagnosis disclosure (n = 58, 27%). Eight percent of reported stressors qualified as traumatic events according to DSM-5. Five (1.8%), 15 (5.3%) and 20 (7.0%) cancer survivors met DSM-5 criteria for current PTSD, lifetime PTSD and AjD, respectively. Among all PTSD cases, three were cancer-related (1.1%). In addition, seven patients (2.5%) met all symptoms for cancer-related PTSD, but not the DSM-5 criterion for medical trauma. Considering receiving the cancer diagnosis as traumatic event, which is debatable according to DSM-5, 38% of stressors qualified as traumatic and six patients (2.1%) met criteria for cancer-related PTSD.

CONCLUSIONS

DSM-5 criteria enable a clear identification of traumatic events in the context of cancer. This change may inform discussions on the appropriateness of PTSD in cancer patients and facilitates its differentiation from AjD. Larger studies need to validate our findings.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Nanomedicines for the treatment of hematological malignancies

Hematological malignancies (HM) are a collection of malignant transformations originating from cells in the primary or secondary lymphoid organs. Leukemia, lymphoma, and multiple myeloma comprise the three major types of HM. Current treatment consists of bone marrow transplantation, radiotherapy, immunotherapy and chemotherapy. Although, many chemotherapeutic drugs are clinically available for the treatment of HM, the use of these agents is limited due to dose-related toxicity and lack of specificity to tumor tissue. Moreover, the poor pharmacokinetic profile of most of the chemotherapeutics requires high dosage and frequent administration to maintain therapeutic levels at the target site, both increasing adverse effects. This underlines an urgent need for a suitable drug delivery system to improve efficacy, safety, and pharmacokinetic properties of conventional therapeutics. Nanomedicines have proven to enhance these properties for anticancer therapeutics. The most extensively studied nanomedicine systems are lipid-based nanoparticles and polymeric nanoparticles. Typically, nanomedicines are small sub-micron sized particles in the size range of 20-200 nm. The biocompatible and biodegradable nature of nanomedicines makes them attractive vehicles to improve drug delivery. Their small size allows them to extravasate and accumulate at malignant sites passively by means of the enhanced permeability and retention (EPR) effect, resulting from rapid angiogenesis and inflammation. Moreover, the specificity to the target tissue can be further enhanced by surface modification of nanoparticles. This review describes currently available therapies as well as limitations and potential advantages of nanomedicine formulations for treatment of various types of HM. Additionally, recent investigational and approved nanomedicine formulations and their limited applications in HM are discussed.

Helical tomotherapy and systemic targeted therapies in solitary plasmacytoma: Pilot study

AIM: To assess the feasibility of the combination of helical tomotherapy^® (HT) and a concurrent systemic targeted therapy in patients with solitary plasmacytoma (SP) with the aim to decrease toxicity while improving therapeutic efficacy.

METHODS: Six patients with biologically, histologically, and radiologically confirmed SP were treated using HT and a systemic targeted treatment concomitantly. Total dose was 40 Gy/20 fractions. Four patients received 4 cycles of concurrent lenalidomide-dexamethasone combination and two patients were treated with concomitant bortezomib-dexamethasone. All toxicities were described using the Common Terminology Criteria for Adverse Effects v3.0.

RESULTS: Five patients had a bone tumor and one patient had an isolated pancreatic mass. Five patients presented with pain, one had neurologic symptoms related to medullary compression, which was treated by an emergency surgery. Median age was 59.5 years (range, 50-74 years). All patients had initial positron emission tomography-computed tomographys, three patients had total body bone magnetic resonance imaging examination, and three patients had computed tomodensitometry scans. The toxicity profile was excellent with no higher than grade 1 toxicity. Four of the six patients experienced a partial radiological response, four had complete response on positions emission tomography and 5/6 patients experienced a complete relief of their symptoms 4 mo after treatment. At a median follow-up of 18 mo, 5/6 patients were controlled clinically, radiologically, and biologically.

CONCLUSION: Using HT, we could deliver a highly conformal irradiation concurrently with a molecularly targeted therapy. This association yielded in a high response rate and a low toxicity. A prospective study with longer follow-up will help determining the true benefit of such strategy.

Is there a role for consolidative radiotherapy in the treatment of aggressive and localized non-Hodgkin lymphoma? A systematic review with meta-analysis

BACKGROUND

Chemotherapy is the mainstay of non-Hodgkin lymphoma (NHL) treatment. Based on expert opinion, the use of radiotherapy (RT) is currently preferred in some institutions as consolidative treatment for patients with localized disease. The lack of conclusive data coming from conflicting studies about the impact of treatment demands a systematic review, which could provide the most reliable assessment for clinical decision-making. We evaluate the addition of RT post-CT, for aggressive and localized NHL (ALNHL).

METHODS

Randomized controlled trials (RCT) that evaluated chemotherapy alone versus chemotherapy plus RT were searched in databases. The outcomes were overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and toxicity. Risk ratio (RR) and hazard ratio (HR) with their respective 95% confidence intervals (CI) were calculated using a fized-effect model.

RESULTS

Four trials (1,796 patients) met the inclusion criteria. All trials tested the use of RT after systemic therapy comprising anthracycline-based chemotherapy. This systematic review showed that RT enhances PFS after chemotherapy (hazard ratio [HR] 0.81; 95% CI 0.67-0.98; p = 0.03), with no impact on ORR and OS. Some heterogeneity between trials could limit the conclusions about OS. Toxicity data could not be pooled due to differences in reporting adverse events.

CONCLUSIONS

This systematic review with meta-analysis shows no improvement in survival when adding RT to systemic therapy for ALNHL. Our conclusions are limited by the available data. Further evaluations of new RT technologies and its association with biologic agents are needed.

Acute myeloid leukemia and myelodysplastic syndromes after radiation therapy are similar to de novo disease and differ from other therapy-related myeloid neoplasms

PURPOSE

Therapy-related myeloid neoplasms (t-MN) represent a unique clinical syndrome occurring in patients treated with chemotherapy and/or external-beam radiation (XRT) and are characterized by poorer prognosis compared with de novo disease. XRT techniques have evolved in recent years and are associated with significantly reduced bone marrow exposure. The characteristics of post-XRT t-MN in the current era have not been studied.

PATIENTS AND METHODS

We analyzed patients who developed acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) after XRT alone (47 patients) or cytotoxic chemotherapy/combined-modality therapy (C/CMT, 181 patients) and compared them with patients with de novo MDS or AML (222 patients). We estimated bone marrow exposure to radiation and compared the clinical, pathologic, and cytogenetic features and outcome of the XRT patients with the C/CMT patients and with patients with de novo MDS and AML.

RESULTS

Patients with t-MN after XRT alone had superior overall survival (P = .006) and lower incidence of high-risk karyotypes (P = .01 for AML and < .001 for MDS) compared with patients in the C/CMT group. In contrast, there were no significant differences in survival or frequency of high-risk karyotypes between the XRT and de novo groups.

CONCLUSION

AML and MDS diagnosed in the past decade in patients after receiving XRT alone differ from t-MN occurring after C/CMT and share genetic features and clinical behavior with de novo AML/MDS. Our results suggest that post-XRT MDS/AML may not represent a direct consequence of radiation toxicity and warrant a therapeutic approach similar to de novo disease.

The important role of radiation therapy in early-stage diffuse large B-cell lymphoma: time to review the evidence once again

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma in the USA, and approximately one-third of patients present with early stage, localized disease. While significant controversy still exists regarding the appropriate management of these patients, the overwhelming evidence from a wide range of studies over the last 40 years points to the superior efficacy of combined-modality therapy for this disease. The current standard of care for the vast majority of early-stage DLBCL cases now involves a combination of chemotherapy, immunotherapy and consolidation radiotherapy. Using this multimodality approach, very high rates of local control can be achieved, which will translate into significant survival benefits for patients with localized disease. The use of intensive immunochemotherapy without radiation therapy requires formal testing and validation in a randomized clinical trial before it can be used as an alternative treatment regimen for early-stage DLBCL. In this article, we discuss the results of the key randomized trials, critical retrospective studies and recent clinical trials, which collectively address the important role of radiotherapy in the treatment of early-stage DLBCL.

The role of helical tomotherapy in the treatment of bone plasmacytoma

We evaluated the early clinical outcome of patients with solitary bone plasmacytoma (SP) or a solitary lesion of multiple myeloma (MM) treated with helical tomotherapy (HT) compared with 3D conformal radiotherapy (3D-CRT), in terms of target coverage and exposure of critical organs. Ten patients with SP and 3 patients with a solitary lesion of MM underwent radiation therapy (RT) delivered by HT, to a dose of 40 Gy in 20 fractions. Treatment planning was then performed with 3D-CRT and the dosimetric parameters of both techniques were compared. Patients were also assessed for response to treatment and acute toxicities. With a median follow-up of 13 months, 78% of patients with pain before RT had resolution of their symptoms. Coverage of target lesion was adequate with both techniques in 12 of 13 patients. Target coverage was significantly lower for HT (V(95%) = 98.55% vs. 97.15%; p = 0.04, for 3D-CRT and HT, respectively). Target overdoses were also lower with HT (V(105%) = 2.01% vs. 0.19%; p= 0.16), although nonsignificant. Finally, there were no significant differences in organs-at-risk irradiation between both techniques. The early treatment tolerance was excellent, with no toxicity higher than grade I. RT of SP and MM with a solitary lesion can be safely delivered with HT, with no major acute side effects and good symptomatic control. Finally, HT provides a dosimetry similar to that of 3D-CRT in terms of organs-at-risk sparing and target volume coverage.

[Hodgkin's Lymphoma]

With approximately 1500 cases per year in France, Hodgkin's lymphoma (HL) represents only 10 to 15 % of new cases of lymphomas, and 0.5 to 1 % of new cases of cancers. The management of this lymphoproliferative disease has undergone profound conceptual changes over time, allowing at present to obtain a cure rate of 75 to 80 % of all confused stage, and up to 90 % in case of early stage HL. If initial treatment consisted in an exclusive extensive (total or sub-total lymphoid) irradiation whatever the stage may be, the place of radiotherapy in the management of HL has evolved over time but remains today one of the cornerstones of the treatment. It becomes integrated within the framework of combined modality therapies associating chemotherapy then irradiation for the early stage HL, and stays a therapeutic alternative in all situations (in advanced stage and\or recurrent disease) which raises the issue of increasing the locoregional tumor control. Despite the undeniable contribution of radiotherapy in controlling the disease, delayed side effects of treatments are not negligible. So the long-term monitoring of treated patients is essential, mainly because of an increased risk of morbi-mortality due to cardiovascular events and/or secondary cancers. It is important to remember that even today the "Involved Field" irradiation type remains the gold standard, even if we witness at present the emergence of new types of irradiation, which aim to reduce the amount of irradiated tissues to try to limit the risks of delayed radio-induced complications. The purpose of this article is to clarify the specific aspects (epidemiological, radio-anatomical and prognostic characteristics) of HL, as well as the practical modalities of the irradiation (illustrated by a clinical case record) when an indication of radiotherapy is placed for its treatment.

Therapeutic effects of γ-irradiation in a primary effusion lymphoma mouse model

Primary effusion lymphoma (PEL) is a unique and recently identified non-Hodgkin's lymphoma in immunocompromised individuals. PEL is caused by the Kaposi sarcoma-associated herpes virus/human herpes virus 8 (KSHV/HHV-8) and has a peculiar presentation involving liquid growth in the serous body cavity, chemotherapy resistance and poor prognosis. In search of a new therapeutic modality for PEL, we examined the effect of γ-irradiation on PEL-derived cell lines (BCBL-1, BC-1, and BC-3) in vitro and in vivo. An MTT assay and trypan blue exclusion assay revealed that irradiation significantly suppressed cell proliferation in the PEL cell lines in a dose-dependent manner, and induced apoptosis. The PEL cell lines were relatively radiosensitive compared with other hematological tumor cell lines (Raji, Jurkat, and K562 cells). Inoculation of the BC-3 cell line into the peritoneal cavity of Rag2/Jak3 double-deficient mice led to massive ascites formation, and subcutaneous injection of BCBL-1 led to solid lymphoma formation. Total body irradiation (4 Gy × 2) with bone marrow transplantation resulted in the complete recovery of both types of PEL-inoculated mice. These results suggest that total body irradiation with bone marrow transplantation can be successfully applied for the treatment of chemotherapy-resistant PEL.

Solitary plasmocytoma: improvement in critical organs sparing by means of helical tomotherapy

PURPOSE

Helical tomotherapy (HT) was assessed in two patients with paramedullar solitary bone plasmocytoma. We compared doses delivered to critical organs, according HT plan or tridimensional conformal plan.

METHODS AND MATERIALS

One male (patient no. 1), 67 yr-old and one female (patient no. 2), 37-yr-old, with histologically, biologically and radiological confirmed paramedullar solitary plasmocytoma have been treated in our department between November 2007 and February 2008 using HT. The prescription dose was 40 Gy in 20 fractions. This HT treatment planning was compared with a routine dosimetric work that was executed for a standard conformal radiotherapy treatment planning.

RESULTS

Treatment tolerance was excellent, without any side effects. Both patients achieved 9-month complete remission. HT resulted in substantial critical organs sparing. For patient no. 1, dose delivered to 20% of the total intestine volume was reduced from 28 Gy for conformal radiotherapy to 13 Gy for HT. Radiation dose delivered to 20% of the left kidney was reduced from 25 Gy to 7 Gy. For patient no. 2, volume of left lung that received at least 20 Gy was 12% for conformal radiotherapy vs. 6% for HT.

CONCLUSIONS

For paramedullar solitary plasmocytoma, HT has the potential to significantly improve the quality of the dose distribution both in terms of better dose homogeneity within the planning target volume and more efficient sparing of critical organs.

Bioluminescent evaluation of the therapeutic effects of total body irradiation in a murine hematological malignancy model

OBJECTIVE

We investigated the utility of in vivo bioluminescence imaging (BLI) in assessing the therapeutic effects of total body irradiation (TBI) in a murine hematological malignancy model.

MATERIALS AND METHODS

The suspension of Ba/F3 cells transduced with firefly luciferase and p190 BCR-ABL genes was exposed to ionizing radiation, and viable cell numbers and bioluminescent signals were measured serially. Mice intravenously inoculated with the cells underwent TBI at various doses. In vivo BLI was performed repeatedly until spontaneous death, and whole-body bioluminescence signals were determined as an indicator of whole-body tumor burden.

RESULTS

In the cell culture study, bioluminescence signals generally reflected viable cell numbers, despite some overestimation immediately after irradiation. Sublethal TBI in mice transiently depressed the increase in whole-body signals and prolonged survival. Spontaneous death occurred at similar signal levels regardless of radiation dose. A significant negative correlation was found between survival and whole-body signal early after TBI. Significant dose dependence was demonstrated for both survival and signal increase early after TBI and was more evident for signal increase. Lethally irradiated mice without bone marrow transplantation died while showing weak signals. In mice receiving lethal TBI and syngeneic bone marrow transplantation, signal reduction and prolongation of survival were prominent, and whole-body signals at death were similar to those in nonirradiated or sublethally irradiated mice.

CONCLUSION

In vivo BLI allows longitudinal, quantitative evaluation of the response to TBI in mice of a hematological malignancy model. Antitumor effects can be assessed early and reliably using in vivo BLI.

The rationale and role of radiation therapy in the treatment of patients with diffuse large B-cell lymphoma in the Rituximab era

Developments in the evaluation and systemic management of diffuse large B-cell lymphoma (DLBCL) require ongoing assessment of the role of external beam radiotherapy in management. This review assesses data regarding the use of radiotherapy in the initial management of early stage and advanced DLBCL, and considers the implications of bulky and residual disease, and the contribution of PET scanning, to decisions regarding the use of radiotherapy after chemotherapy. Limited R-CHOP plus radiotherapy, or full dose R-CHOP alone, are both likely to cure approximately 90% of patients with low risk early stage disease. The choice of therapy will depend on considerations of acute and late toxicity of the two approaches, taking into account individual patient risk profiles and preferences. Unfavorable early-stage and advanced-stage disease require treatment with full dose R-CHOP. The presence of bulky disease predicts for a higher risk of relapse, which may be partly ameliorated by the addition of radiotherapy. The rapidity of response on PET scanning, the presence of a posttherapy residual mass, the potential toxicity of radiotherapy and the available salvage options all need to be considered on a patient by patient basis, when considering the use of radiotherapy for advanced disease.

Therapeutic radiation for lymphoma: risk of malignant mesothelioma

BACKGROUND

Ionizing radiation has been used since the 1950s to treat a variety of cancers. Cancer patients who are treated with radiotherapy have shown increased risks for a variety of second malignancies, including mesothelioma, in several recent reports. The only existing study of Hodgkin lymphoma (HL) and subsequent mesothelioma had a short observation period.

METHODS

The authors used Surveillance, Epidemiology, and End Results data over a 30-year period to identify patients with HL and non-Hodgkin lymphoma (NHL) who also were diagnosed with mesothelioma. Standardized incidence ratios (SIR) and absolute excess risks were calculated by sex and treatment modality for both types of lymphoma.

RESULTS

Twenty-six patients were identified who had mesothelioma as second primaries based on 21,881 diagnoses of HL and 101,001 diagnoses of NHL. There was a statistically significant increase in mesothelioma (4 diagnoses; SIR, 6.59; 95% confidence interval [95% CI], 1.79-16.87) among men with HL who received radiation, but no women survivors were identified who had a diagnosis of mesothelioma. For NHL survivors, there was a nonsignificant excess of mesothelioma among men (SIR, 1.91; 95% CI, 0.77-3.93) and women (SIR, 3.75; 95% CI, 0.77-10.95) who had received radiation treatment. There were no increases among patients who were unirradiated.

CONCLUSIONS

Mesothelioma rates for patients who had received radiotherapy were increased for survivors of HL and NHL. No increases were observed among the unirradiated. These findings and the existing body of supporting studies confirmed that radiotherapy is a cause of mesothelioma.

Spinal cord injury caused by epidural B-cell lymphoma: report of two cases

BACKGROUND/OBJECTIVE

Spinal cord injury (SCI) caused by cancer is increasing in incidence as the mean age of our patient population increases. Understanding the prognosis and functional outcome requires knowledge of diseases of the spinal column. This paper presents the unusual presentation of epidural B-cell lymphoma.

METHODS

Case reports.

RESULTS

Two patients presented with an unusual cause of SCI, namely B-cell lymphoma. Both patients presented with sensory deficits greater than motor deficits and gait disorder. Both achieved functional independence at the community ambulation level and tumor remission with chemotherapy and radiation therapy.

CONCLUSIONS

B-cell epidural tumors are an uncommon cause of SCI. Functional outcome can be quite good, as can tumor outcome. Residual sensory deficits greater than motor deficits are not uncommon.