Update on the Pathogenesis, Diagnosis, and Therapy of AIDS-related Lymphoma

How I treat HIV-associated lymphoma

Over the past 10 years, significant progress has been made in understanding HIV-associated lymphomas and improving the prognosis of these diseases. With the advent of combination antiretroviral therapy and the development of novel therapeutic strategies, most patients with HIV-associated lymphomas are cured. The outcome for the majority of patients with HIV-associated diffuse large B-cell lymphoma and Burkitt lymphoma in particular, is excellent, with recent studies supporting the role of rituximab in these diseases. Indeed, in the combination antiretroviral therapy era, the curability of many patients with HIV-associated lymphoma is similar to their HIV-negative counterparts. New treatment frontiers need to focus on improving the outcome for patients with advanced immune suppression and for those with adverse tumor biology, such as the activated B-cell type of diffuse large B-cell lymphoma and the virally driven lymphomas. Future clinical trials need to investigate novel targeted agents alone and in combination with chemotherapy.

Interventions for previously untreated patients with AIDS-associated non-Hodgkin's lymphoma

BACKGROUND

Human immunodeficiency virus (HIV) infection is known to be associated with an increased risk of non-Hodgkin's lymphoma (NHL). The majority of lymphomas (>80%) occurring during immunosuppression are aggressive B-cell in origin and have a high-to-intermediate histology grade. Treatment of NHL is not standardized.

OBJECTIVES

To assess the clinical effectiveness and safety of single agent or combination chemotherapy with or without immunochemotherapy (rituximab) and with or without highly active antiretroviral therapy (HAART) on overall survival (OS) and disease-free survival (DFS) for previously untreated patients with AIDS-related NHL.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2009), MEDLINE (1966-March 6, 2009), EMBASE (1988-March 6, 2009), LlLACS (1982 to February 17, 2009), Gateway (March 6, 2009), and AIDSearch (2006 -February 2008) were used to identify published, potentially eligible trials. Further, we searched several electronic sources. For additional information see the Cochrane HIV/AIDS Group search strategy.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the effectiveness of systemic treatments for previously untreated AIDS-related NHL. There were no age or language restrictions.

DATA COLLECTION AND ANALYSIS

Authors independently assessed relevant studies for inclusion; four RCTs were selected. No meta-analysis was attempted due to clinical heterogeneity.

MAIN RESULTS

Four RCTs that included 857 patients (number range: 30 to 485) met the inclusion criteria. The studies have a high risk of bias; three RCTs were conducted in the United States and one was a multi-national, multi-centre RCT performed in France and Italy. One of the trials included only men. It was impossible to pool data for any of the outcomes due to the differences in the interventions assessed in these RCTs. Overall survival did not differ significantly between treatment groups. Disease free survival (DFS) was reported in two of the four RCTs, but it was not statistically significant between treatment groups.

AUTHORS' CONCLUSIONS

We found no evidence that the systemic interventions for untreated patients with AIDS-related NHL provide superior clinical effectiveness for improving OS, DSF, and tumour response rate; however, this conclusion is based on four RCTs with limited sample size and variable quality. More adequately powered RCTs that have low risk of bias are necessary to determine the real benefit or harm of interventions to treat this population. Overall survival (OS), DFS, and quality of life should be included as endpoints.

High incidence of occult leptomeningeal disease detected by flow cytometry in newly diagnosed aggressive B-cell lymphomas at risk for central nervous system involvement: the role of flow cytometry versus cytology

We assessed the cerebrospinal fluid (CSF) by flow cytometry and cytology in 51 newly diagnosed and 9 treated aggressive B-cell lymphomas at risk for central nervous system (CNS) involvement to examine the utility of flow cytometry, incidence of CSF disease, and clinical surrogates of CNS spread. Multicolor flow cytometry using multiple antibody panels for light chains and B- and T-cell antigens identified neoplastic clones that constituted as little as 0.2% of total CSF lymphocytes. Among 51 newly diagnosed patients, 11 (22%) had occult CSF involvement. All 11 were detected by flow cytometry but only 1 by cytology (P = .002). Among 9 treated patients, CSF involvement was detected by flow cytometry alone in 2 and also by cytology in 1 case. CSF chemistry and cell counts were similar in patients with and without CSF lymphoma. Only the number of extranodal sites was associated with occult CSF lymphoma in newly diagnosed patients by univariate (P = .006) or logistic regression analysis (P = .012). We hypothesize that the biologic phenotype associated with colonization of extranodal sites leads to CNS spread, possibly related to the microenvironment. Patients at risk for CNS spread should undergo staging CSF evaluation by flow cytometry.