AIDS Related Small Non-Cleaved (Burkitt or Atypical Burkitt) Lymphoma Versus Diffuse Large Cell Lymphoma in the Pre- and Post-HAART Eras: Significant Differences in Survival.

Introduction: While intensive chemotherapy is recommended for the treatment of non-HIV related small non-cleaved cell lymphoma (SNC), optimal treatment of AIDS-related SNC is unknown, as previous studies in patients (pts) with AIDS-related lymphoma have not considered differences in histologic characteristics. The purpose of this retrospective study was to compare the clinical characteristics and outcome of AIDS-related SNC with those of diffuse large cell/immunoblastic lymphoma (DLCL), in the pre-HAART and post-HAART eras.

Methods: We reviewed the data on 135 HIV infected pts with SNC and 227 HIV + pts with DLCL seen at our institution from 1982 to January 2004. ALL other histologic subtypes were excluded. All cases were reviewed by one expert hematopathologist (BNN). As highly active antiretroviral therapy (HAART) first became available to us in 1996, pre-HAART and post-HAART periods were defined as before and after 1996.

Results: There were 117 cases of SNC (45%) and 143 cases of DLCL in the pre-HAART era vs 18 SNC (18%) and 84 DLCL in the post-HAART era (p<0.0001). As shown, there were no significant differences between the two groups at diagnosis in terms of age, sex, performance status, stage, median LDH level, median CD4 count and previous history of opportunistic infections (OI) or Kaposi’s sarcoma. However, pts with AIDS-associated SNC were more likely to have involvement of bone marrow (BM), liver, and kidney. Most patients were treated with CHOP (cyclophosphamide, vincristine, adriamycin, prednisone) or m-BACOD (methotrexate, bleomycin, adriamycin, cyclophosphamide, vincristine, dexamethasone), regimens which have been shown to be equivalent in prospective studies. Median overall survival (OS) in HIV pts with SNC was not different from that in DLCL in the pre-HAART era (6.0 versus 7.6 months, p= 0.97). However, in the post-HAART era, the OS of pts with DLCL was significantly longer than that of pts with SNC (38 versus 5.6 months, p= 0.0006).

Demographics, HIV Characteristics, Treatment and Overall Survival

Conclusions: (1) Bone marrow, kidney and liver involvement are more common in AIDS-related SNC versus DLCL (2) SNC is statistically less common in the post-HAART era than pre-HAART (3) After CHOP or m-BACOD, OS was similar for both histologic subtypes in the pre-HAART era. (4) After CHOP or m-BACOD in the post-HAART era, OS of pts with AIDS related SNC is significantly shorter than that for pts with DLCL, suggesting that the current practice of using a uniform regimen for both histologic subtypes should be reviewed.