Successful treatment of AIDS-associated, primary CNS lymphoma with rituximab- and methotrexate-based chemotherapy and autologous stem cell transplantation

Diagnosis and Treatment Using Autologous Stem-Cell Transplantation in Primary Central Nervous System Lymphoma: A Systematic Review

BACKGROUND

Consolidation therapy has improved the outcome of newly diagnosed PCNSL patients. Whole-brain radiotherapy (WBRT) was the first consolidation strategy used and represented the gold standard for many years, but at the expense of a high risk of neurotoxicity. Thus, alternative strategies are being investigated in order to improve disease outcomes and to spare the neurocognitive side effects due to WBRT.

METHODS

We reviewed published studies on PCNSL patients treated with HDC/ASCT, focusing on the efficacy and safety of the conditioning regimens. Prospective and retrospective studies, published in the English language from 1992 to 2022, in high-quality international journals were identified in PubMed.

RESULTS

Consolidation with HDC containing highly CNS-penetrating agents (thiotepa, busulfan or BCNU) followed by ASCT provided long-term disease control and survival in PCNSL patients. Two prospective randomized studies, comparing HDC/ASCT versus WBRT, reported similar progression-free survival (PFS) and similar results on the decline in neurocognitive functions in a substantial proportion of patients after WBRT but not after HDC-ASCT. A recent randomized study comparing HDC/ASCT versus non-myeloablative consolidation reported a longer PFS in transplanted patients.

CONCLUSION

ASCT conditioned with regimens, including highly CNS-penetrating agents, represents, to date, the best choice among the available consolidation strategies for fit newly diagnosed PCNSL patients.

Primary central nervous system lymphoma in patients with and without HIV infection: a multicenter study and comparison with U.S national data

PURPOSE

Primary central nervous system lymphoma (PCNSL) in patients living with HIV (PLWH) is a distinct entity; however, the management is adopted from patients without HIV. The study aims to examine the differences in presentation, treatment, and outcomes of PCNSL patients with or without HIV.

METHODS

We retrospectively compared the characteristics of 144 patients with PCNSL with and without HIV, and analyzed factors associated with overall and progression-free survival. Results were compared to the Central Brain Tumor Registry of the United States (CBTRUS) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) system.

RESULTS

Among all patients with PCNSL, 19% had HIV. PLWH were younger (38 vs. 63 years; p < 0.01) and more likely to be African American (59% vs. 7%; p < 0.01) and male (74% vs. 49%; p = 0.02) than patients without HIV. PLWH were more likely to have multiple lesions (67% vs. 43%; p = 0.02), hemorrhage (59 vs. 37%; p = 0.03), and peripheral rim enhancement (57% vs. 7%; p < 0.01) on imaging; to receive palliative care (15% vs. 2%) or whole brain radiation (63% vs. 3%); and less likely to receive chemotherapy (22% vs. 95%) (p < 0.01). Twenty-four patients, none PLWH, underwent stem cell transplant. Not receiving transplant was an independent factor in mortality and disease progression. Our cohort of patients, compared to the national database, were younger (60 vs. 65 years), 58% were white vs. 75%, and had longer median overall survival 43 vs. 25 months.

CONCLUSION

Epidemiology, imaging, and treatment options for patients with PCNSL with and without HIV differ, but HIV was not an independent factor of mortality or disease progression. More efforts are needed to improve access to research and treatment options for PLWH with PCNSL.

Stem cell transplantation in strategies for curing HIV/AIDS

HIV-1 can persist in a latent form in resting memory CD4+ cells and macrophages carrying an integrated copy of the HIV genome. Because of the presence of these stable reservoir cells, eradication by antiretroviral therapy is unlikely and in order to achieve eradication, alternative treatment options are required. Stem cell transplantation has been considered previously to effect the clinical course of HIV-infection but in practice eradication or virus control was not achievable. However, modifications of stem cell transplantation using natural or artificial resistant cell sources, combination with new techniques of gene editing or generating cytotoxic anti HIV effector cells have stimulated this field of HIV cell therapy substantially. Here, we look back on 30 years of stem cell therapy in HIV patients and discuss most recent developments in this direction.

Clinical management of HIV-associated hematologic malignancies

HIV is associated with an excess risk for lymphoid malignancies. Although the risk of lymphoma has decreased in HIV-infected individuals in the era of effective combination antiretroviral therapy, it remains high. Treatment outcomes have improved due to improvements in HIV and cancer therapeutics for the common HIV-associated lymphomas. R-CHOP/R-EPOCH are the standard of care for HIV-associated diffuse large B-cell lymphoma. HIV-infected patients with Burkitt lymphoma and good performance status should receive dose-intensive regimens. HIV-infected patients with primary central nervous system lymphoma can respond favorably to high-dose methotrexate-based therapy. In many cases, treatment and expected outcomes for HIV-infected patients with either Hodgkin or non-Hodgkin's lymphomas are very similar to HIV-negative patients. There is currently no standard treatment for HIV-associated multicentric Castleman disease or primary effusion lymphoma. For those hematologic cancers in which transplantation is part of standard care, this modality should be considered an option in those with well-controlled HIV infection.

Primary CNS lymphoma

Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system is an aggressive malignancy that exhibits unique biological features and characteristic clinical behaviour, with overall long-term survival rates of around 20–40 %. Clinical outcome has improved following the advent of chemoradiation protocols incorporating high-dose methotrexate in the mid-1980s, but disease relapse and adverse neurocognitive sequelae remain major clinical challenges. To address this, investigators have focused on improving drug therapy with novel cytotoxic combinations, monoclonal antibody therapy, and intensive chemotherapy consolidation approaches, in an attempt to improve disease control whilst reducing the requirement for whole-brain radiotherapy. Outcomes for patients that are older, immunocompromised, or have relapsed/refractory disease remain unsatisfactory and there is a paucity of clinical trial data to guide treatment of these groups. This review highlights recent advances in pathobiology, imaging, and clinical management of PCNSL and looks ahead to research priorities for this rare and challenging lymphoid malignancy.