Current Clinical Trials

Until the 1980s, primary central nervous system lymphoma (PCNSL) was a rare disease. PCNSL has increased dramatically in association with acquired immunodeficiency syndrome (AIDS).[1] PCNSL accounts for approximately 0.6% of initial AIDS diagnoses and is the second most frequent central nervous system (CNS) mass lesion in adults with AIDS. As with other AIDS-related lymphomas, these are usually aggressive B-cell neoplasms, either diffuse large cell or diffuse immunoblastic non-Hodgkin lymphoma. Unlike AIDS-related systemic lymphomas, in which 30% to 50% of tumors are associated with Epstein-Barr virus (EBV), AIDS-related PCNSL has been reported to have a 100% association with EBV.[2] This percentage indicates a pathogenetic role for EBV in this disease. These patients usually have evidence of far-advanced AIDS, are severely debilitated, and present with focal neurologic symptoms such as seizures, changes in mental status, and paralysis.

Computed tomographic scans show contrast-enhancing mass lesions that may not always be distinguished from other CNS diseases, such as toxoplasmosis, that occur in AIDS patients.[3] Magnetic resonance imaging studies using gadolinium contrast may be a more useful initial diagnostic tool in differentiating lymphoma from cerebral toxoplasmosis or progressive multifocal leukoencephalopathy. Lymphoma tends to present with large lesions, which are enhanced by gadolinium. In cerebral toxoplasmosis, ring enhancement is very common, lesions tend to be smaller, and multiple lesions are seen.[4-6] Use of positron emission scanning has demonstrated an improved ability to distinguish PCNSL from toxoplasmosis.[7,8] PSNCL has an increased uptake while toxoplasmosis lesions are metabolically inactive. Antibodies against toxoplasmosis may also be very useful because the vast majority of cerebral toxoplasmosis occur as a consequence of reactivity of a previous infection. If the IgG titer is less than 1:4, the disease is unlikely to be toxoplasmotic. A lumbar puncture may be useful to detect as many as 23% of patients with malignant cells in their cerebrospinal fluid (CSF). Evaluating the CSF for EBV DNA may be a useful lymphoma-specific tool since EBV is present in all patients with PCNSL. Despite all of these evaluations, however, the majority of patients with PCNSL require a pathologic diagnosis.[9-11] Diagnosis is made by biopsy. Sometimes, a biopsy is attempted only after failure of antibiotics for toxoplasmosis, which will produce clinical and radiographic improvement within 1 to 3 weeks in patients with cerebral toxoplasmosis.[12] PCNSL is often identified as a terminal manifestation of AIDS or on postmortem examination.

Radiation therapy alone has usually been used in this group of patients. With doses in the 35 Gy to 40 Gy range, median duration of survival has been only 72 to 119 days.[3,13,14] Survival is longer in younger patients with better performance status and the absence of opportunistic infection.[15] Most patients respond to treatment by showing partial improvement in neurologic symptoms. Autopsies have revealed that these patients die of opportunistic infections as well as tumor progression. Treatment of these patients is also complicated by other AIDS-related CNS infections, including subacute AIDS encephalitis, cytomegalovirus encephalitis, and toxoplasmosis encephalitis. Spontaneous remissions have been reported after highly active antiretroviral therapy.[16]

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with AIDS-related primary CNS lymphoma ¹. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site ².

References

1. Ziegler JL, Beckstead JA, Volberding PA, et al.: Non-Hodgkin's lymphoma in 90 homosexual men. Relation to generalized lymphadenopathy and the acquired immunodeficiency syndrome. N Engl J Med 311 (9): 565-70, 1984.  [PUBMED Abstract]
   
   
2. MacMahon EM, Glass JD, Hayward SD, et al.: Epstein-Barr virus in AIDS-related primary central nervous system lymphoma. Lancet 338 (8773): 969-73, 1991.  [PUBMED Abstract]
   
   
3. Goldstein JD, Dickson DW, Moser FG, et al.: Primary central nervous system lymphoma in acquired immune deficiency syndrome. A clinical and pathologic study with results of treatment with radiation. Cancer 67 (11): 2756-65, 1991.  [PUBMED Abstract]
   
   
4. Nyberg DA, Federle MP: AIDS-related Kaposi sarcoma and lymphomas. Semin Roentgenol 22 (1): 54-65, 1987.  [PUBMED Abstract]
   
   
5. Fine HA, Mayer RJ: Primary central nervous system lymphoma. Ann Intern Med 119 (11): 1093-104, 1993.  [PUBMED Abstract]
   
   
6. Ciricillo SF, Rosenblum ML: Use of CT and MR imaging to distinguish intracranial lesions and to define the need for biopsy in AIDS patients. J Neurosurg 73 (5): 720-4, 1990.  [PUBMED Abstract]
   
   
7. Hoffman JM, Waskin HA, Schifter T, et al.: FDG-PET in differentiating lymphoma from nonmalignant central nervous system lesions in patients with AIDS. J Nucl Med 34 (4): 567-75, 1993.  [PUBMED Abstract]
   
   
8. Pierce MA, Johnson MD, Maciunas RJ, et al.: Evaluating contrast-enhancing brain lesions in patients with AIDS by using positron emission tomography. Ann Intern Med 123 (8): 594-8, 1995.  [PUBMED Abstract]
   
   
9. Cinque P, Brytting M, Vago L, et al.: Epstein-Barr virus DNA in cerebrospinal fluid from patients with AIDS-related primary lymphoma of the central nervous system. Lancet 342 (8868): 398-401, 1993.  [PUBMED Abstract]
   
   
10. Cingolani A, De Luca A, Larocca LM, et al.: Minimally invasive diagnosis of acquired immunodeficiency syndrome-related primary central nervous system lymphoma. J Natl Cancer Inst 90 (5): 364-9, 1998.  [PUBMED Abstract]
    
    
11. Yarchoan R, Jaffe ES, Little R: Diagnosing central nervous system lymphoma in the setting of AIDS: a step forward. J Natl Cancer Inst 90 (5): 346-7, 1998.  [PUBMED Abstract]
    
    
12. Mathews C, Barba D, Fullerton SC: Early biopsy versus empiric treatment with delayed biopsy of non-responders in suspected HIV-associated cerebral toxoplasmosis: a decision analysis. AIDS 9 (11): 1243-50, 1995.  [PUBMED Abstract]
    
    
13. Baumgartner JE, Rachlin JR, Beckstead JH, et al.: Primary central nervous system lymphomas: natural history and response to radiation therapy in 55 patients with acquired immunodeficiency syndrome. J Neurosurg 73 (2): 206-11, 1990.  [PUBMED Abstract]
    
    
14. Remick SC, Diamond C, Migliozzi JA, et al.: Primary central nervous system lymphoma in patients with and without the acquired immune deficiency syndrome. A retrospective analysis and review of the literature. Medicine (Baltimore) 69 (6): 345-60, 1990.  [PUBMED Abstract]
    
    
15. Corn BW, Donahue BR, Rosenstock JG, et al.: Performance status and age as independent predictors of survival among AIDS patients with primary CNS lymphoma: a multivariate analysis of a multi-institutional experience. Cancer J Sci Am 3 (1): 52-6, 1997 Jan-Feb.  [PUBMED Abstract]
    
    
16. McGowan JP, Shah S: Long-term remission of AIDS-related primary central nervous system lymphoma associated with highly active antiretroviral therapy. AIDS 12 (8): 952-4, 1998.  [PUBMED Abstract]