Primary CNS lymphoma

Histopathological and medico-legal aspects in a case of death related to an undiagnosed cerebral large B-cell lymphoma

We report an unusual and undetected case of primary central nervous system lymphoma presenting as multiple lesions in the periventricular occipital lobe in an immunocompetent host, which had manifested as a stroke. The neoplastic diagnosis was made only after death following a thorough autopsy and histopathological examinations which enabled the diagnosis of a rare cancer (primary cerebral lymphoma) which remained undetected and undiagnosed during life.

MYC/BCL2 Co-Expression Is a Stronger Prognostic Factor Compared With the Cell-of-Origin Classification in Primary CNS DLBCL

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) is a subtype of DLBCL with an unfavorable prognosis and a poor response to the treatment. As we know, DLBCL is stratified into germinal center B-cell (GCB)-like and activated B-cell (ABC)-like subtypes with different prognosis according to their gene-expression characteristics. In this study, we analyzed a case series of 77 patients with primary CNS DLBCL. A difference in prognosis of GCB-like and ABC-like subtypes was noticed, but no statistical significance was found. However, significant prognostic value of MYC/BCL2 co-expression was shown. The cases with MYC/BCL2 co-expression did not show any predominance of the 2 subtypes in our cases. Furthermore, patients with MYC/BCL2 co-expression had significantly worse overall survival for both cell of origin (COO) subtypes. We conjecture that MYC/BCL2 co-expression is associated with a poorer prognosis and is independent of COO classification. Moreover, the data suggest that MYC/BCL2 co-expression is superior to COO classification assessed by immunohistochemical analysis in patients with primary CNS DLBCL.

Brain stereotactic biopsy flow cytometry for central nervous system lymphoma characterization: advantages and pitfalls

BACKGROUND

Brain stereotactic biopsy (SB) followed by conventional histopathology and immunohistochemistry (IHC) is the gold standard approach for primary central nervous system lymphoma (PCNSL) diagnosis. Flow cytometry (FCM) characterization of fine-needle aspiration cytology and core needle biopsies are increasingly utilized to diagnose lymphomas however, no biological data have been published on FCM characterization of fresh single cell suspension from PCNSL SB. The aim of this study was to establish the feasibility and utility of FCM for the diagnosis and characterization of brain lymphomas from a tissue samples obtained by a single SB disaggregation.

METHODS

Twenty-nine patients with a magnetic resonance suggestive for PCNSL entered the study. A median of 6 SB were performed for each patient. A cell suspension generated from manual tissue disaggregation of a single, unfixed, brain SB, was characterized by FCM. The FCM versus standard approach was prospectively compared.

RESULTS

FCM and IHC showed an high degree of agreement (89 %) in brain lymphoma identification. By FCM, 16 out of 18 PCNSL were identified within 2 h from biopsy. All were of B cell type, with a heterogeneous CD20 mean fluorescence intensity (MFI), CD10 positive in 3 cases (19 %) with surface Ig light chain restriction documented in 11 cases (69 %). No false positive lymphomas cases were observed. Up to 38 % of the brain leukocyte population consisted of CD8 reactive T cells, in contrast with the CD4 positive lymphocytes of the peripheral blood samples (P < 0.001). By histopathology, 18 B-PCNSL, only one CD10 positive (5 %), 1 primitive neuroectodermal tumor (PNET) and 10 gliomas were diagnosed. A median of 6 days was required for IHC diagnosis.

CONCLUSION

Complementary to histopathology FCM can contribute to a better characterization of PCNSL, although necrosis and previous steroid treatment can represent a pitfall of this approach. A single brain SB is a valid source for accurate FCM characterization of both lymphoma and reactive lymphocyte population, routinely applicable for antigen intensity quantification and consistently documenting an active mechanism of reactive CD8 T-lymphocytes migration in brain lymphomas. Moreover, FCM confirmed to be more sensitive than IHC for the identification of selected markers.

Clinical outcomes of patients with newly diagnosed primary central nervous system lymphoma are comparable on treatment with high-dose methotrexate plus temozolomide and with high-dose methotrexate plus cytarabine: a single-institution experience

The role of temozolomide in untreated PCNSL patients has not yet been clearly defined. The purpose of this study was to compare the efficacy and toxicity of MT and MC chemotherapy in this population. A total of 41 consecutive patients were enrolled from March 2001 to July 2011. The ORR and CRR for MT vs. MC were 70% vs. 61.9% and 45% vs. 38.1% on ITT basis, (p = NS); 73.7% vs. 68.4% and 47.4% vs. 42.1% on PP basis, respectively (p = NS). Grade 3-4 hematological toxicities were more common in MC than in MT group (85.7% vs. 15%, p = 0.0001). One treatment-related death was observed in each group. The 5-year PFS and OS of MT (36% and 62.2%) were comparable to MC (32.6% and 46.7%), (p = NS). In summary, our preliminary results suggest that MT combination may be a simplified and effective regimen comparable to MC for newly diagnosed PCNSL.

The effect of ABCG2 and ABCC4 on the pharmacokinetics of methotrexate in the brain

Methotrexate (MTX) is the cornerstone of chemotherapy for primary central nervous system lymphoma, yet how the blood-brain barrier (BBB) efflux transporters ABCG2 and ABCC4 influence the required high-dose therapy is unknown. To evaluate their role, we used four mouse strains, C57BL/6 (wild-type; WT), Abcg2(-/-), Abcc4(-/-), and Abcg2(-/-);Abcc4(-/-) (double knockout; DKO) to conduct brain microdialysis studies after single intravenous MTX doses of 50 mg/kg. When the area under the concentration-time curve for plasma (AUC(plasma)) was used to assess systemic exposure to MTX, the rank order was Abcc4(-/-) < WT < Abcg2(-/-) < Abcg2(-/-)Abcc4(-/-). Only the DKO exposure was significantly higher than that of the WT group (P < 0.01), a reflection of the role of Abcg2 in biliary excretion and Abcc4 in renal excretion. MTX brain interstitial fluid concentrations obtained by microdialysis were used to calculate the area under the concentration-time curve for the brain (AUC(brain)), which found the rank order of exposure to be WT < Abcc4(-/-) < Abcg2(-/-) < Abcg2(-/-)Abcc4(-/-) with the largest difference being 4-fold: 286.13 ± 130 μg*min/ml (DKO) versus 66.85 ± 26 (WT). Because the transporters affected the systemic disposition of MTX, particularly in the DKO group, the ratio of the AUC(brain)/AUC(plasma) or the brain/plasma partition coefficient Kp was calculated, revealing that the DKO strain had a significantly higher value (0.23 ± 0.09) than the WT strain (0.11 ± 0.05). Both Abcg2 and Abcc4 limited BBB penetration of MTX; however, only when both drug efflux pumps were negated did the brain accumulation of MTX significantly increase. These findings indicate a contributory role of both ABCG2 and ABCC4 to limiting MTX distribution in patients.

O6-methylguanine-DNA methyltransferase (MGMT) immunohistochemistry as a predictor of resistance to temozolomide in primary CNS lymphoma

Temozolomide, an alkylating agent, has shown promise in treating primary central nervous system lymphoma (PCNSL). The enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) repairs alkylating damage, such as that induced by temozolomide. We hypothesized that MGMT immunohistochemistry would predict resistance to temozolomide in PCNSL. A retrospective study of newly-diagnosed and recurrent PCNSL patients treated at our institution was conducted to study the predictive value of MGMT immunohistochemistry for response to temozolomide. 20 patients who were treated with temozolomide as a single agent were identified during the study time period. 6/20 patients demonstrated a response, corresponding to an objective response rate of 30 % (95 % CI 8-52). Five patients with low MGMT level (<30 %) showed a response to temozolomide. Only one of 10 patients (10 %) with high MGMT level (≥30 %) exhibited a response to temozolomide. Small sample numbers precluded formal statistical comparisons. Two patients with complete response remain alive without progressive disease 6.7 and 7.2 years after temozolomide initiation. Immunohistochemistry can be performed on small biopsies to selectively assess MGMT status in tumor versus surrounding inflammation. MGMT analysis by immunohistochemistry may predict response to temozolomide in PCNSL and should be prospectively investigated.

Anti-LFA-1 antibodies enhance metastasis of ocular lymphoma to the brain and contralateral eye

Previously we demonstrated that intraperitoneal (IP) inoculation of Rev-2-T-6 mouse lymphoma into syngeneic Balb/c hosts resulted in brain metastasis, migration along the optic nerve sheath, and ocular infiltration. In a second model: intravitreal inoculation of Rev-2-T-6 cells, the developing lymphoma was largely confined within the eye, seldom breaching the retinal pigment epithelium to reside in the choroid and sclera. There was no retrograde infiltration into the brain. Here, we describe a third, complementary model, whereby intravitreal inoculation of Rev-2-T-6 cells into Balb/c mice, followed by repeated IP inoculations of anti-LFA-1/CD11a monoclonal antibodies, results in extensive infiltration of the choroid, sclera, conjunctiva, eyelids and orbit. Furthermore, the lymphoma cells metastasize along the optic nerve sheath into the brain, and through the contralateral optic nerve tract into the contralateral eye. There is no systemic involvement of the lymphoma. Furthermore, anti-LFA-1 treatment results in elevated levels of serum anti-Rev-2-T-6 antibodies. Inoculation of Rev-2-T-6 cells into the vitreous of severe combined immune deficient mice demonstrates a course of clinical signs and histopathological findings similar to those in immune-competent mice treated with anti-LFA-1 antibodies, including invasion of the contralateral eye. Taken together, these findings suggest that confinement of Rev-2-T-6 lymphoma cells to the eye depends on active immune surveillance using a population of effector cells expressing the cell surface integrin LFA-1. Impairing this protection enhances tumor aggressiveness within the eye, and the likelihood of early retrograde lymphoma metastasis into the brain and the contralateral eye.

Interleukin-8 in the pathogenesis of primary central nervous system lymphoma in association with HIV infection

The pathogenesis of acquired immunodeficiency syndrome-associated primary central nervous system lymphoma (AIDS-associated PCNSL) remains unclear. However, cell adhesion molecules have been reported to be strongly associated with PCNSL. In this study, we established Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) from HIV-positive patients (LCL(HIV)) and normal individuals (LCL(N)). The expression of CD18 antigen by LCL(HIV) was stronger than that by LCL(N). We performed a cell adhesion assay using ISO-HAS, which is the human hemangiosarcoma cell line and expresses intercellular adhesion molecule 1 (CD54). The binding rates of LCL(HIV) and ISO-HAS without stimulation were higher than those of LCL(N). Further, we demonstrated that azidothymidine or simvastatin inhibited the binding rates of LCL(HIV) and ISO-HAS more significantly than those of LCL(N). Further, the levels of interleukin (IL)-8, a CD18 inducer, were higher in LCL(HIV) than in LCL(N). We conclude that interaction between IL-8 and CD18 may be critical to AIDS-related PCNSL.

Primary central nervous system lymphoma

PURPOSE OF REVIEW

This review will summarize recent advances in the understanding and treatment of primary central nervous system lymphoma (PCNSL).

RECENT FINDINGS

The molecular and genetic characteristics that distinguish PCNSL are beginning to be elucidated. New tools such as flow cytometry and PET are improving the diagnosis and management of PCNSL. Although the current standard of care is high-dose methotrexate-based chemotherapy alone or in combination with whole brain radiotherapy, multiple questions remain regarding the optimal treatment of PCNSL, in general, and unusual variants of PCNSL.

SUMMARY

Although recent advances have improved our understanding of PCNSL, the need for additional collaborative research is critical.

Treatment of primary CNS lymphoma with high-dose methotrexate in immunocompetent pediatric patients

We report two cases of primary CNS lymphoma (PCNSL) treated with high-dose methotrexate. Though standard adult treatment of PCNSL incorporates whole-brain radiotherapy, the literature suggests it may be possible to delay or avoid radiotherapy and the associated increased risk of neurologic sequelae in pediatric patients. Studies in adults indicate methotrexate therapy can be effective against PCNSL and has advantages over the current standard of treatment. Both patients have no evidence of disease 9 and 7 years after treatment, suggesting high-dose methotrexate may lead to disease control in pediatric patients with PCNSL while avoiding the effects of radiotherapy.

High-dose methotrexate with or without whole brain radiotherapy for primary CNS lymphoma (G-PCNSL-SG-1): a phase 3, randomised, non-inferiority trial

BACKGROUND

High-dose methotrexate is the standard of care for patients with newly diagnosed primary CNS lymphoma. The role of whole brain radiotherapy is controversial because delayed neurotoxicity limits its acceptance as a standard of care. We aimed to investigate whether first-line chemotherapy based on high-dose methotrexate was non-inferior to the same chemotherapy regimen followed by whole brain radiotherapy for overall survival.

METHODS

Immunocompetent patients with newly diagnosed primary CNS lymphoma were enrolled from 75 centres and treated between May, 2000, and May, 2009. Patients were allocated by computer-generated block randomisation to receive first-line chemotherapy based on high-dose methotrexate with or without subsequent whole brain radiotherapy, with stratification by age (<60 vs ≥60 years) and institution (Berlin vs Tübingen vs all other sites). The biostatistics centre assigned patients to treatment groups and informed local centres by fax; physicians and patients were not masked to treatment group after assignment. Patients enrolled between May, 2000, and August, 2006, received high-dose methotrexate (4 g/m(2)) on day 1 of six 14-day cycles; thereafter, patients received high-dose methotrexate plus ifosfamide (1·5 g/m(2)) on days 3-5 of six 14-day cycles. In those assigned to receive first-line chemotherapy followed by radiotherapy, whole brain radiotherapy was given to a total dose of 45 Gy, in 30 fractions of 1·5 Gy given daily on weekdays. Patients allocated to first-line chemotherapy without whole brain radiotherapy who had not achieved complete response were given high-dose cytarabine. The primary endpoint was overall survival, and analysis was per protocol. Our hypothesis was that the omission of whole brain radiotherapy does not compromise overall survival, with a non-inferiority margin of 0·9. This trial is registered with ClinicalTrials.gov, number NCT00153530.

FINDINGS

551 patients (median age 63 years, IQR 55-69) were enrolled and randomised, of whom 318 were treated per protocol. In the per-protocol population, median overall survival was 32·4 months (95% CI 25·8-39·0) in patients receiving whole brain radiotherapy (n=154), and 37·1 months (27·5-46·7) in those not receiving whole brain radiotherapy (n=164), hazard ratio 1·06 (95% CI 0·80-1·40; p=0·71). Thus our primary hypothesis was not proven. Median progression-free survival was 18·3 months (95% CI 11·6-25·0) in patients receiving whole brain radiotherapy, and 11·9 months (7·3-16·5; p=0·14) in those not receiving whole brain radiotherapy. Treatment-related neurotoxicity in patients with sustained complete response was more common in patients receiving whole brain radiotherapy (22/45, 49% by clinical assessment; 35/49, 71% by neuroradiology) than in those who did not (9/34, 26%; 16/35, 46%).

INTERPRETATION

No significant difference in overall survival was recorded when whole brain radiotherapy was omitted from first-line chemotherapy in patients with newly diagnosed primary CNS lymphoma, but our primary hypothesis was not proven. The progression-free survival benefit afforded by whole brain radiotherapy has to be weighed against the increased risk of neurotoxicity in long-term survivors.

Neurologic presentations of AIDS

The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurred an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome).

Radiotherapy for patients with the human immunodeficiency virus: are special precautions necessary?

Shortly after the onset of the acquired immunodeficiency syndrome (AIDS) epidemic in the 1980s, reports of radiation-associated toxicity in patients with the human immunodeficiency virus (HIV) and AIDS began to appear in the medical literature. Although the majority of reports have focused on AIDS-defining malignancies such as Kaposi sarcoma, greater-than-expected toxicity after a course of radiotherapy or chemoradiotherapy has also been documented in cancers not generally classified as being related to HIV. With improved antiretroviral therapies, HIV patients are living longer and have the potential to develop a variety of HIV-associated and nonassociated malignancies that require treatment, including radiotherapy. This review reports the published data regarding the interactions of HIV, AIDS, and antiretroviral therapy with radiotherapy and implications for the management of malignancies in patients with HIV.