Treatment of Burkitt lymphoma in children and adults: Lessons from Africa

Outcome of pediatric non-Hodgkin lymphoma in Central America: A report of the Association of Pediatric Hematology Oncology of Central America (AHOPCA)

BACKGROUND

Treating B-non-Hodgkin lymphoma (B-NHL) in lower-income countries is challenging because of imprecise diagnosis, the increased risk of fatal toxicity associated with advanced disease at presentation, and limited supportive care.

PROCEDURE

Central American patients with newly diagnosed stage I or II B-NHL received a modified Berlin-Frankfurt-Münster (BFM) regimen including a prephase (prednisone, cyclophosphamide) followed by A/B/A courses (A: cytarabine, dexamethasone, etoposide, ifosfamide, methotrexate, and intrathecal therapy; B: cyclophosphamide, dexamethasone, doxorubicin, methotrexate, and intrathecal therapy). Those with stage III or IV NHL received additional courses (B/A/B), intensified for stage IV disease by additional vincristine and methotrexate doses. Patients in poor condition received a second prephase treatment before their chemotherapy courses.

RESULTS

Between March 2004 and June 2016, of 405 patients with B-NHL, 386 (109 females) were eligible for treatment. Immunohistochemistry was performed in 177 cases (47.4%) and characterized the disease as mature B-cell lymphoma. Stage distribution was as follows: I/II, 31 (8.1%); III, 252 (65.3%); IV, 93 (24.1%); 10 (2.6%) not available. The 3-year overall survival was 70% for the whole group (86% for stages I/II, 75% for stage III, 58% for stage IV). Events included death during induction (34 patients, 8.8%), relapse/progression (46, 11.9%), death in remission (9, 2.3%), second malignancy (1, 0.26%), and death of unknown cause (1, 0.26%). Twenty-three (6%) patients abandoned or refused therapy.

CONCLUSIONS

Approximately 70% of children with B-NHL from Central America experienced long-term, disease-free survival with a modified BFM schedule. Toxic death and relapse/resistant disease were the main reasons for treatment failure.

Interobserver variation is a significant limitation in the diagnosis of Burkitt lymphoma

CONTEXT

The pathology of classic Burkitt lymphoma (BL) remains a challenge despite being a well-defined entity, in view of the significant overlap with atypical BL and B-cell lymphoma intermediate between DLBL (diffuse large B cell lymphoma) and BL. They are difficult to be segregated in resource-limited setups which lack molecular testing facilities. This is further affected by interobserver variability and experience of the reporting pathologist.

AIMS

The aim of our study was to quantitate variability among a group of pathologists with an interest in lymphomas (albeit with variable levels of experience) and quantitate the benefit of joint discussions as a tool to increase accuracy and reduce interobserver variability of pathologists, in the diagnosis of BL in a resource-limited setup.

MATERIALS AND METHODS

A set of 25 non-Hodgkin lymphoma cases in which a diagnosis of BL was entertained were circulated to 14 participating pathologist within the Mumbai lymphoma study group. A proforma recorded the morphologic and immunohistochemical features perceived during the initial independent diagnosis followed by a consensus meeting for discussion on morphology and additional information pertinent to the case.

STATISTICAL ANALYSIS AND RESULTS

The concordance was poor for independent diagnosis among all the pathologists with kappa statistics (±SE) of 0.168 (±0.018). Expert lymphoma pathologists had the highest (albeit only fair) concordance (kappa = 0.373 ± 0.071) and general pathologists the lowest concordance (kappa = 0.138 ± 0.035). Concordance for morphological diagnosis was highest among expert lymphoma pathologists (kappa = 0.356 ± 0.127). Revision of diagnoses after consensus meeting was highest for B-cell lymphoma intermediate between DLB and BL. To conclude, interobserver variation is a significant problem in BL in the post WHO 2008 classification era. Experience with a larger number of cases and joint discussion exercises such as the one we conducted are needed as they represent a simple and effective way of improving diagnostic accuracy of pathologists working in a resource-limited setup.

Towards curative therapy in burkitt lymphoma: the role of early african studies in demonstrating the value of combination therapy and CNS prophylaxis

This paper describes the treatment of Burkitt lymphoma (BL) from the time of its discovery in Africa up to the present. Pioneer investigators explored the value of chemotherapy since surgery and radiation were not effective modalities. Complete response was observed with many drugs used as single agents, but Ziegler and colleagues showed that patients resistant to one drug could achieve cure and potentially long-term survival with other drugs. Subsequently, a combination of cyclophosphamide (CTX), vincristine (VCR), and methotrexate (MTX) was shown to be active, but a survival advantage compared to CTX alone could not be demonstrated because effective CNS prophylactic therapy, in the form of intrathecal therapy, was not given. A recent re-evaluation of this regimen in Africa with multiple doses of intrathecal therapy compares favourably with recent studies of single agent CTX, and other drugs have been shown to be non-cross resistant. Optimal results for patients with extensive disease probably require 5 or 6 effective drugs along with intrathecal therapy, using MTX and Ara-C. In Africa, doses must be lower, because of limitations in supportive care, but in technically advanced countries cure rates in excess of 90% can be obtained. Rituximab may improve the results in some patient groups and allow less intensive therapy without a reduction in survival in others.

Denis Burkitt and the African lymphoma

Burkitt lymphoma has provided a model for the understanding of the epidemiology, the molecular abnormalities that induce tumours, and the treatment of other lymphomas. It is important to remember that the early phases of this work were conducted in Africa where today, unfortunately, the disease usually results in death because of limited resources, even though most children in more developed countries are cured. This must be changed. In addition, it is time to re-explore, with modern techniques, some of the questions that were raised some 50 years ago shortly after Burkitt's first description, as well as new questions that can be asked only in the light of modern understanding of the immune system and the molecular basis of tumor development. The African lymphoma has taught us much, but there is a great deal still to be learned.