Burkitt’s lymphoma: Etioloy, pathology, prognosis and treatment

Etiology: There are three types of Burkitt’s Lymphoma: Endemic (African), Sporadic (non-African) and HIV-associated per WHO classification. Compared to the endemic type which is commonly associated with EBV infection, the incidence of EBV is lower in the other two types (20% in sporadic and 30- 40% in HIV patients). Burkitt’s Lymphoma is distinguished from diffuse large-B-cell lymphoma by the high level of expression of c-myc, the expression of germinal-center B-cell genes, and the low level of MHC class I genes and nuclear factor-kappa target genes. Immunodeficiency-associated Burkitt’s lymphoma occurs mainly in patients infected with HIV but also occurs in allograft recipients and individuals with congenital immunodeficiency. Burkitt’s lymphoma accounts for 30%-40% of non-Hodgkin’s lymphoma in HIV+ patients. Burkitt’s lymphoma is estimated to be 1,000 times more common in HIV+ individuals. HIV+ patients with Burkitt’s lymphoma are younger, less often carry a prior diagnosis of AIDS, and have higher mean CD4 counts. HIV-associated Burkitt’s lymphoma shares some pathogenetic features with endemic Burkitt’s lymphoma. Patients with Burkitt’s lymphoma have a median age of 54.5 years with a CR rate of 72% and a lymphoma free long-time survival of 55%. The International Prognostic Index IPI is the most valuable prognostic factor for survival. Favorable disease by Murphy’s system is stage I or stage IIR and normal LDH. Symptoms: Endemic Burkitt’s lymphoma most commonly involves the maxilla and/or mandible; however, abdominal organs may also be involved. A tumor can double in size in 18 hours. Presentation is commonly with swelling of the affected jaw bones and rapidly enlarging, non-tender lymph nodes in the neck or jaw. Sporadic Burkitt’s lymphoma usually involves the abdominal organs, most frequently the distal ileum, caecum or mesentery. Other abdominal and pelvic organs, glandular tissue (such as the thyroid and tonsils) and the facial bones may also be involved. Presentation is commonly with abdominal mass/swelling and ascites, intestinal obstruction. B symptoms may be present with both forms of Burkitt’s lymphoma and include fever, weight loss, night sweats. HIVrelated Burkitt’s lymphoma tends to present in a similar way to the sporadic disease. Treatment Options: Treatment of Burkitt’s lymphoma in younger and fit patients is R-HyperCVAD, R-CODOX/MVAC. For low-risk disease with single site of disease >10 cm and a normal LDH, 3 cycles of R-CODOX-M are considered. For older patients more than 60 years of age R-EPOCH is preferred but R-HyperCVAD could be considered for select older fit patients. Salvage chemotherapy options for relapsed Burkitt’s lymphoma are aggressive CCE or other ALL induction regimens. Allogeneic transplants may be considered for fit patients who obtain second CR. The patient should receive CNS prophylaxis with each cycle of chemotherapy. For HIV-related Burkitt’s lymphoma, a dose-Adjusted R-EPOCH is again considered a preferred treatment. For young, fit patients with wellcontrolled HIV and good CD4⁺ counts R-HyperCVAD and R-CODOXM/IVAC could be considered as alternative treatment options. The overall survival is superior among those who receive intensive chemotherapy regimens instead of lower-dose regimens.