Abdominal Burkitt-type lymphomas in Algeria

Epstein-Barr virus and Burkitt's lymphoma. Associations in Iraqi Kurdistan and twenty-two countries assessed in the International Incidence of Childhood Cancer

Background

Burkitt's lymphoma (BL) has worldwide variations in incidence that are related to the age of Epstein-Barr virus (EBV) infection. This study examined the age-specific incidence rate (ASIR) of BL and community EBV seropositivity in Iraqi Kurdistan and compared results with data from countries tabulated in the International Incidence of Childhood Cancer volume 3 (IICC-3).

Methods

The ASIR (95% confidence intervals) of BL in Sulaimani Governorate of Iraqi Kurdistan were calculated for the years 2010–2020. Specimens from 515 outpatients were tested for IgG and IgM antibodies to EBV viral capsid antigen.

Results

In Sulaimani, 84% of BL occurred under 20 years of age, with an ASIR of 6.2 (4.7–7.7) per million children. This ASIR was not significantly different than that of Egypt, Morocco, Israel, Spain, or France. It was slightly higher than the ASIR of the United States, the United Kingdom, and Germany and markedly higher than for Asia and South Africa. In Africa and much of Asia, early childhood EBV exposure predominates, with nearly all children being infected by 5 years of age. In Sulaimani, just over 50% of children were EBV seropositive at 3 years old and 90% seropositivity was reached at 15 years of age. In Europe and North America, seropositivity is commonly delayed until adolescence or young adulthood and adult predominates over childhood BL.

Conclusion

In the Middle East, childhood BL is relatively common and adult BL is rare. In Sulaimani, EBV seropositivity increases progressively throughout childhood and reaches 92% at mid-adolescence. This may reflect the Mid East more widely. We suggest that the high childhood and low adult BL rates may be a regional effect of a pattern of EBV exposure intermediate between early childhood and adolescent and young adult infections.

Seroepidemiological analysis and literature review of the prevalence of Epstein-Barr virus and herpesvirus infections in pediatric cases with non-Hodgkin lymphoma in Central Europe

BACKGROUND

Epstein-Barr virus (EBV) is linked to a variety of malignancies; most endemic Burkitt lymphoma (BL) harbor EBV, whereas only a subset of the cases of sporadic BL is EBV positive.

PROCEDURE

We retrospectively determined the herpesvirus seroprevalence at the time of diagnosis in pediatric non-Hodgkin lymphoma (NHL) patients enrolled in NHL-BFM (Berlin-Frankfurt-Muenster) studies. We accessed the seroepidemiological data from 1147 patients that became available during 1990-2007. We included the records from patients 6 months to 18 years of age with BL, T-cell lymphoblastic lymphoma (T-LBL), lymphoblastic precursor B-cell lymphoma (pB-LBL), diffuse large B-cell lymphoma (DLBCL), or anaplastic large cell lymphoma (ALCL).

RESULTS

EBV seropositivity was significantly more frequent in patients with BL than in those with T-LBL. EBV was more prevalent in patients younger than 6 years of age and in patients with BL than in those with non-BL or T-LBL. Event-free survival was significantly lower in varicella-zoster-seronegative patients, but there was no indication of an association to complications due to varicella zoster infection. We found no associations between herpes simplex virus, varicella zoster virus, or human cytomegalovirus seroprevalence and the pediatric Central European NHL cases.

CONCLUSION

Early EBV exposure may increase the risk of BL in Central Europe. A higher involvement of EBV in European BL than originally reported appears at least probable. Our data support the thesis that the distinction between endemic and sporadic BL is artificial and should be replaced by the differentiation between EBV-positive and EBV-negative BL.

Current investigations and treatment of Burkitt's lymphoma in Africa

We reviewed the scientific literature on Burkitt's lymphoma (BL) in Africa in order to provide information on the current status of clinical care and the existing research challenges. BL epidemiology led to the discovery of the Epstein Barr virus, an important cause of several viral illnesses and malignancies. The incidence of BL has increased in the endemic areas of Africa, overlapping with the epidemic of HIV and increase of malaria. The impact of this on the clinical care of BL in the region is therefore of interest, especially in HIV-infected children. Rapid methods must be developed which enable the correct diagnosis to be made. It is important to improve supportive care to allow fairly aggressive treatment, to research into salvage therapy for those who fail first-line treatment, and to develop less toxic drug combinations for HIV-infected patients. Documentation of HIV status through counselling should be offered to all patients.

Oral Burkitt's lymphoma in children: the Moroccan experience

Thirty-seven children with Burkitt's lymphoma of the oral region diagnosed between 1998 and 2005 were reviewed. There were 31 boys and 6 girls. The mean age at diagnosis was 6.64 years (range 2-15 years) with a mean delay to diagnosis of 41 days (range 10 days-2 months). There was a predominance of maxillary over mandibular involvement: 1.44:1. Complaints included exophytic mass with dental displacement (100%), abdominal pain (68%), nerve palsy (28%) and orbital swelling (21%). Toothache as initial complaint led to dental extraction in 12 cases. According to the Murphy classification, there were 4 stage II, 11 stage III and 22 stage IV tumours; 43% and 41% had bone marrow and central nervous system involvement, respectively. After chemotherapy, complete remission was seen in 59% of cases. Remission in two children was relatively brief, lasting no more than 3 months. After a median follow-up of 45 months (range 9-99 months), the disease-free survival rate was 54%. In conclusion, in this series, oral presentation of Burkitt's lymphoma was a component of more widely disseminated disease. The pattern seemed to fall between that of the endemic and the sporadic types. Even with intensive chemotherapy, patients with advanced disease maintained a poor prognosis.

Expression of EBV encoded nuclear small non-polyadenylated RNA (EBER) molecules in 32 cases of childhood Burkitt's lymphoma from Israel

We have analyzed paraffin sections from 32 children with histologically confirmed Burkitt's Lymphoma (BL) for the presence of EBV using in situ hybridization to detect expression of the EBV-encoded early RNAs (EBERs). EBV was present in the tumors of 11 patients (34%). Sixty nine percent of the children presented with abdominal disease, 19% had bone marrow infiltration and only one child had jaw involvement. There was no statistically significant difference between EBV positive and EBV negative children with regard to age, gender, origin, primary site at presentation, or clinical stage of disease. However, there was a trend for younger age in the children with EBV positive BL with a median age of 4, compared to 7 years in children with EBV negative BL. None of the 7 children of Ashkenazi Jewish origin had EBER positive disease. There was no difference in the treatment outcome between the EBV positive patients (estimated survival at 24 months of 82%) and EBV negative children (estimated survival rate of 71% (p=0.58)). In conclusion, although this is only a small series it seems that childhood BL in Israel has the clinical characteristics of sporadic, non-African type with 34% EBV association and a low incidence of jaw tumors. Our data suggest that Ashkenazi Jewish children with BL are less likely to have EBV positive tumors than other ethnic groups. However, more patients will need to be studied in order to assess the validity of this observation.

Pathology of intestinal lymphomas

The advent of immunohistological and molecular techniques has enabled the comprehensive characterization of many lymphoma entities. Furthermore, it has increased the consensus in lymphoma classification among pathologists. In this review we describe the pathological features of primary intestinal lymphomas classified according to the revised European-American classification of lymphoid neoplasms. The majority of primary intestinal lymphomas are of B-cell lineage and most of these are high-grade tumors. By morphology they may be classified as diffuse large B-cell lymphomas of centroblastic, immunoblastic or plasmablastic type and Burkitt lymphomas. The latter occur predominantly in the terminal ileum and affect children or young adults. Low-grade extra-nodal marginal-zone lymphoma of the mucosa-associated lymphoid tissue (MALT) type and, less frequently, follicular center-cell lymphomas are the low-grade B-cell lymphomas most commonly observed in this region. The first mentioned tumor and its specific intestinal variant, alpha-chain disease or immunoproliferative small intestinal disease are well known for their indolent clinical course. Primary intestinal mantle-cell lymphoma often presents as multiple lymphomatous polyposis and similarly to its node-based equivalent is associated with an unfavorable prognosis. Most primary intestinal T-cell lymphomas display a characteristic immunophenotype, particular histological features with prominent epitheliotropism and are often associated with celiac disease indicating that these tumors form a specific lymphoma type. It has been termed intestinal T-cell lymphoma or enteropathy-type T-cell lymphoma. Clinically, these are aggressive diseases with a high mortality rate. In summary, primary intestinal lymphomas consist of several entities which display distinct clinicopathological features thus confirming the relevance of lymphoma typing.

Epstein-barr virus-associated malignancies: epidemiologic patterns and etiologic implications

Epstein-Barr virus (EBV), a ubiquitous B-lymphotrophic herpesvirus, has been found in the tumor cells of a heterogeneous group of malignancies (Burkitt's lymphoma, lymphomas associated with immunosuppression, other non-Hodgkin's lymphomas, Hodgkin's disease, nasopharyngeal carcinoma, gastric adenocarcinoma, lymphoepithelioma-like carcinomas, and immunodeficiency-related leiomyosarcoma). As the epidemiologic characteristics of these cancers have not been considered together, this review seeks to relate their incidence patterns and risk factors to EBV biology and virus-host interaction in an attempt to help elucidate factors involved in EBV-related carcinogenesis. We include a brief review of EBV virology and primary infection to provide a biologic context for considering the epidemiology, summarize the most salient epidemiologic features of each malignancy, synthesize epidemiologic data by risk factor to uncover commonalities and informative contrasts across the diseases, and propose hypotheses regarding etiologic mechanisms, based on the possible effect of the risk factors at various stages in the viral life cycle.

Preliminary report of an intensified, short duration chemotherapy protocol for the treatment of pediatric non-Hodgkin's lymphoma in India

BACKGROUND

In the past, the results of the treatment of non-Hodgkin's lymphomas (NHL) in Indian children have been poor, due to inadequate chemotherapy and poor supportive care. In an attempt to overcome these problems, we conducted a clinical trial in Bombay with a new protocol, MCP842.

PATIENTS AND METHODS

Seventy-four previously untreated patients < 25 years were entered on study at the Tata Memorial Hospital, Bombay. Patients with lymphoblastic lymphoma (LL) (38) without bone marrow involvement and all patients with small noncleaved cell lymphoma (SNCL) (18) and large cell lymphoma (LCL) (18) were eligible. Treatment consisted of alternating cycles of two regimens, A and B. Patients with St. Jude stages I and II received six cycles, and those with stages III or IV received eight cycles. A cycles included cyclophosphamide, adriamycin, vincristine and ara-C, and B cycles, etoposide, vincristine, methotrexate, ifosfamide and mesna.

RESULTS

Complete response was achieved in 67 (91%) of patients. Event free survival (EFS) for all patients was 58%; 68% for patients with SNCL and LCL combined, and 48% for patients with LL. There was no significant difference in EFS by histology (LL versus non-LL), or stage. There were nine (12%) toxic deaths, two during induction and seven in patients in remission; six occurred in patients with LL.

CONCLUSIONS

These results are better than past results in Bombay. Unlike earlier CCG protocols, in which the outcome between patients with LL and non-LL differed, this was not so in MCP842. Even patients with extensive LL without bone marrow disease received only eight cycles of therapy, suggesting that short duration therapy is curative in as many as half of such patients--an important observation in a country with limited resources.

Management of paediatric lymphoma

The high cure rate obtained in most paediatric lymphomas allows an optimistic vision of future treatments, with decreased primary late effects observed in patients who have completed therapy: decreased cognitive functional impairment, reproductive dysfunction, poor social adaptation, and risk of second malignancies. The deleterious effects of radiation therapy on neurocognitive functions is now well documented (Meadows et al, 1981) but, apart from rare acute toxicities (Sasazaki et al, 1992), reports on those following high-dose methotrexate are scarce, and sometimes discordant (Jannoun and Chessels, 1987; Robertson et al, 1992). Longer follow-up evaluation is warranted before definitive conclusions concerning the relationship between computed tomography scan findings and clinical outcome can be reached. The reproductive function of males is much more severely altered than that of females (Jaffe et al, 1988). Several reports have demonstrated the major dose-dependent toxicity of alkylating agents on male fertility. Male patients receiving more than 9 g/m2 of cyclophosphamide have a particularly high risk of sterility (Aubier et al, 1989) and children with less than 4 g/m2 of cyclophosphamide, a very low risk Patte et al, 1996a). Women treated before the age of 20 who do not receive abdominal irradiation usually have normal reproductive function, although early puberty (Quigley et al, 1989) and early menopause (Byrne et al, 1992) have been documented. The risk of a second malignancy is not as great as in children with a solid tumour or Hodgkin's disease (Anderson et al, 1993). The risk is higher in patients treated with alkylating agents (Lemerle et al, 1989). With the increasing cure rate, a social problem may arise for adults who "have had cancer'. The increased awareness by politicians and health insurance companies should help to solve, at least partially, this new problem (Monaco, 1987). As cure rates increase, emerging concerns involve the familial repercussions of this heavy treatment (Lansky et al, 1978; Cairns et al, 1979). At this stage, there is no demonstrated deleterious effect from treatment for the progeny of cured children (Mulvihill et al, 1987; Stein, 1993). Cure of children with lymphoma is a reality, and one should think in terms of "complete cure' when facing a distressed child with a heavy tumour burden arriving for diagnosis (Schweisguth, 1979). Since 1980, the progress of molecular biology techniques has permitted the precise molecular characterization of gene alterations (oncogenes, immunoglobulins, and T-cell receptor genes) involved in the process of malignant transformation of normal lymphocytes (Bhatia et al, 1996; Williams et al, 1996). In parallel, treatment of malignant NHL of childhood has improved dramatically. The progress in molecular biology has not led to a modification of the clinical management of NHL of childhood which remains mainly empirical. Precise cytohistological classification of lymphomas has resulted in the characterization of low- and high-risk patients requiring distinct therapeutic approaches. The major goals of the next few years will be to increase the cure rates of those patients with CNS and bone marrow involvement at diagnosis, probably through an intensification of chemotherapy (increase in the dose or intensity of the chemotherapy); to define precisely subgroups of good-prognosis patients requiring less aggressive treatment that would decrease the risk of long-term events; and to salvage previously heavily treated patients at relapse. The precise analysis of gene alterations in lymphoma cells of a given patient may have important clinical applications in this respect (Bhatia et al, 1996).

The investigation of Epstein-Barr viral sequences in 41 cases of Burkitt's lymphoma from Egypt: epidemiologic correlations

BACKGROUND

Epstein-Barr virus (EBV) is associated with many human neoplasms, including Burkitt's lymphoma (BL). Endemic BL in central Africa is more often EBV-associated than BL in the United States, where seroconversion for EBV occurs somewhat later than in Africa. Therefore, the EBV association rate in BL may correlate more with the socioeconomic status of the population studied, which influences the age of EBV seroconversion, than with such factors as malaria, which may relate to the overall higher incidence rate in endemic regions.

METHODS

Forty-one patients with BL in Egypt, which differs both climatically and racially from central African countries (i.e., Kenya, Uganda) where BL is endemic, were analyzed. All biopsies were evaluated for EBV-encoded RNAs (EBER1) by RNA in situ hybridization, analyzed for p53 protein expression using the monoclonal antibody D07, and immunophenotyped using a panel of monoclonal antibodies that included L26 (CD20), Leu 22 (CD43), and A6 (CD45RO). Twelve cases were evaluable for EBV subtype by polymerase chain reaction with EBV-specific primers.

RESULTS

The median age at diagnosis was 9 years (range, 2-22 years). The biopsy site was extranodal in 29 patients and nodal in 12 patients. All 41 cases were documented as B-cell neoplasms. A hybridization signal for EBER1 RNA was identified in greater than 95% of the neoplastic cells in 30 of 41 cases (73%), whereas no signal was observed in 11 cases (27%). Epstein-Barr virus subtype 1 was found in 10 patients, subtype 2 in two patients. Immunostaining for p53 was observed in greater than 5% of the neoplastic cells in 9 of 37 cases (24%). No significant correlation was observed between EBV positivity and sex, biopsy site, or p53 immunostaining.

CONCLUSIONS

The prevalence of EBV in BL from Egypt is slightly lower than in BL in endemic regions, but significantly higher than in sporadic BL. Epstein-Barr virus positivity probably reflects the socioeconomic status of the patient population, and age at seroconversion. The prevalence of EBV subtype 1 suggests that immunodeficiency does not play a role in Egyptian Burkitt's lymphoma, in contrast to endemic Burkitt's lymphoma, in which holoendemic malaria is thought to contribute to immunodeficiency, a higher incidence rate, and the observed prevalence of subtype 2.

Immunophenotypic analysis of childhood Burkitt's lymphoma in the West Midlands 1957-1986

AIMS

To analyse the immunophenotype of a large number of non-endemic Burkitt's lymphomas to determine whether a B cell phenotype is consistently recognisable using formalin fixed, paraffin wax embedded archival material and a standard panel of commercially available antibodies.

METHODS

Archival material was obtained from 30 cases of childhood Burkitt's lymphoma registered with the West Midlands Regional Children's Tumour Research Group. These were analysed by a standard avidin biotin complex immunoperoxidase method using antibodies to CD45, CD43, CD30, CD20, CD15, and immunoglobulin heavy and light chains.

RESULTS

There was a high incidence of the CD45RB and CD20 immunophenotypes, with a clearly recognisable B cell lineage even in archival material. IgM was identifiable in 13 of the 23 (56.5%) cases tested. Only three of 17 (18%) cases expressed CD30. Positive membrane staining with CD45RO was observed in two (6.7%) cases.

CONCLUSIONS

A B cell lineage can be identified in Burkitt's lymphoma in formalin fixed, paraffin wax embedded material, even in archival tissue. There was a low incidence of membrane staining with CD45RO which is a potential source of diagnostic confusion.

Gastrointestinal lymphoma

Primary gastrointestinal lymphoma comprises a group of distinctive clinicopathological entities, most of which are not included in current lymph node-based lymphoma classifications. They may be of B- or T-cell type, with primary gastrointestinal Hodgkin's disease being extremely uncommon. Most low grade B-cell gastrointestinal lymphomas are of mucosa-associated lymphoid tissue (MALT) type, so called because they recapitulate the features of MALT rather than those of lymph nodes. Paradoxically, however, most MALT lymphomas arise in the stomach, which normally contains no organized lymphoid tissue. These gastric MALT lymphomas appear to arise in MALT acquired as a reaction to infection of the stomach by Helicobacter pylori and their growth can be influenced by eradication of this organism from the stomach. Low grade MALT lymphomas, which usually have a very favorable clinical course, may undergo high grade transformation; high grade tumours also may arise de novo and these probably also belong to the MALT group. Immunoproliferative small intestinal disease (IPSID) is a special form of MALT lymphoma with a restricted geographic distribution, which is characterized by synthesis of alpha heavy-chain immunoglobulin. Other gastrointestinal B-cell lymphomas include mantle cell lymphoma, which presents as lymphomatous polyposis, and Burkitt's or Burkitt-like lymphoma. Enteropathy (celiac disease)-associated T-cell lymphoma (EATL) is the most common primary gastrointestinal T-cell lymphoma. This is a clinically aggressive tumor that arises from the intraepithelial T-cell population, which is increased in celiac disease.

Burkitt's lymphoma: a model for clinical oncology

Burkitt's lymphoma, a pathological entity initially described in Africa, is the most common childhood lymphoma in western countries and represents approximately 5% of all adults lymphomas. This high grade small non-cleaved diffuse lymphoma is a model with which to study the relations between cancer and viruses, the chromosomes and the genes. Burkitt's lymphoma is also a model for clinical research which allows evaluation of the dose effect concept with chemotherapy and the role of megatherapy with autologous bone marrow rescue.

International variations in the incidence of childhood lymphomas

The International Agency for Research on Cancer has coordinated a worldwide study of childhood cancer incidence, with data provided by contributors from over 50 countries. We present here the results on lymphomas from this study and other sources. Hodgkin's disease had a relatively high incidence in North Africa and West Asia and a low incidence throughout East Asia. In populations of predominantly European origin, the highest rates tended to be in warmer countries of lower latitude. In industrialised Western countries, the incidence increased steeply with age and was low in childhood compared with that in young adults whereas elsewhere the increase in incidence between childhood and adults aged 20-34 was much less marked. The age-distribution of Hodgkin's disease in childhood appears to be related to levels of socio-economic development but the total incidence seems to be determined more by ethnic and environmental factors. The highest incidence of Burkitt's lymphoma occurred in tropical Africa and Papua New Guinea. Elsewhere, Burkitt's lymphoma was rare, though the incidence was higher in Spain, North Africa and the Middle East than in other areas. In most Western countries, a third of all non-Hodgkin lymphomas may be Burkitt's. There was no consistent pattern in the incidence of other non-Hodgkin lymphomas except for a tendency towards higher rates around the Mediterranean and in some Latin American registries.

Immunology of gastrointestinal lymphoma

Experimental work showing that IgA plasma cell precursors activated in gut associated lymphoid tissue (GALT) of rats and sheep migrate to the lamina propria of the gut via the regional lymphatics, mesenteric lymph node and blood, has been supported by immunohistochemical studies. In rats, immunoblasts with cytoplasmic IgA are present in the Peyer's patches in association with the high endothelial venules which is probably an important, though not the only, site of extravasation into the gut, whereas cells with cytoplasmic IgA are rarely observed in the dome regions of Peyer's patches. Immunohistochemical studies of human Peyer's patches have revealed differences between the distribution of cells with cytoplasmic IgA in man compared to rats. In man, immunoblasts with cytoplasmic IgA are not concentrated in the zone of cells containing the high endothelial venules, whereas they are present in the dome regions of the Peyer's patches. The following questions arise: Do precursors of IgA plasma cells activated in human GALT migrate to the lamina propria via the blood, but extravasate predominantly via the capillary network, rather than the high endothelial venules? or do IgA plasma cell precursors 'mature' in situ in the Peyer's patches of man and subsequently migrate laterally to seed the lamina propria? Three lines of evidence from studies of primary B cell lymphomas of GALT support the latter hypothesis: 1) Primary B cell lymphomas of the gut remain localized to GALT for long periods of time; 2) Histological studies of the lymphoid tissue in these lymphomas have shown a gradation of cell types, from the muscularis mucosae towards the mucosal epithelium, which strongly suggests that plasma cells develop in situ in the gut from the adjacent layers of cells; 3) Preliminary studies of DNA extracted from the blood-borne cells from patients with GALT-derived B cell lymphoma have failed to demonstrate the presence of clonal gene rearrangements. Normal and malignant human GALT contains a perifollicular population of B cells with centrocyte-like morphology which lack surface IgD. No direct equivalent can be detected in rodent Peyer's patches. Their quiescent nature and distribution in malignant GALT suggests that they are follicle centre cell-derived and precursors of immunoblasts and plasma cells. As such they may be memory B cells. Their association with epithelium is a consistent feature of normal and malignant GALT which is of unknown but undoubted significance. The function of intraepithelial T cells is still unknown. Malignant T cells in MHI may be derived from intraepithelial T cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Non-Hodgkin's lymphomas in childhood. A clinicopathologic and epidemiologic study in Finland

All cases diagnosed in Finland as non-Hodgkin's lymphoma (NHL), Hodgkin's disease or histiocytosis X in children younger than 15 years in 1953 to 1973, according to the Finnish Cancer Registry, were reexamined histologically. Only 55% of the cases originally diagnosed as NHL were regarded as such at reexamination. The others were mainly malignant nonlymphatic tumors such as neuroblastoma and different kinds of sarcomas. Seventy-two NHLs were diagnosed in 50 boys and 22 girls. The corrected age-specific incidence rate was 0.32/10(5). The most common histologic types were Burkitt's lymphoma (BL) (30 cases), lymphoblastic lymphoma (LBL) (26), large cell lymphomas (LCL) (six), and non-Burkitt's lymphoma (n-BL) (three). There were marked differences between BL and LBL in the course of the disease: BL was extranodal in 83%, LBL only in 4% (mediastinum was regarded as nodal); BL showed initial abdominal or pelvic involvement in 60% whereas LBL showed none; BL had initial mediastinal involvement in 7%, and LBL had it in 62%; all patients with LBL died whereas 23% of those with BL survived. Other types of NHL resembled BL in their course of disease. Patients with initial tonsillary involvement appeared to have the best prognosis and patients with mediastinal involvement the poorest. The importance of accurate histologic classification is emphasized. It appears to be most important to differentiate LBL from other types of NHL.

Effective multiagent chemotherapy in children with advanced B-cell lymphoma: who remains the high risk patient?

Between 1981 and 1985, 50 patients, mainly children and adolescents, with advanced B-cell lymphoma were entered on a protocol comprising eight drugs: cyclophosphamide, vincristine, prednisolone, high dose methotrexate, adriamycin, BCNU, cytosine arabinoside and thioguanine. Treatment to the central nervous system consisted of intrathecal methotrexate and cytosine-arabinoside in association with high dose methotrexate without irradiation. Data was collected prospectively with regard to response rate, treatment related complications and survival. Histology was reviewed in all referred cases and in 21 there was supportive evidence from immunological and cytogenetic studies. The overall complete response rate was 86%: 31/36 stage III and 12/14 stage IV. There were four treatment related deaths. The overall disease-free survival is 75% with a median follow up of 32 months. In the group of stage IV patients 5/7 with only marrow involvement, 2/4 with isolated CNS involvement and 1/3 with combined CNS and marrow infiltration survive. All the patients with CNS involvement at presentation underwent consolidation treatment with high dose chemotherapy and bone marrow transplant. These results demonstrate the very high curability of B-cell lymphoma using intensive multiagent therapy even with advanced abdominal disease. Bone marrow infiltration does not appear to be an adverse prognostic factor in isolation from bulk disease or CNS involvement. There remain, however, two groups of patients in whom further intensification of therapy is indicated, namely, those with initial CNS involvement, especially in combination with marrow infiltration, and those with extensive multiorgan involvement at presentation who fail to achieve remission with initial therapy. For the other patients, the large majority, a reduction in the intensity and duration of therapy is currently under study.

Intensive chemotherapy for non-localised Burkitt's lymphoma

Between 1982 and 1984, 24 consecutively diagnosed children from Iraq with non-localised Burkitt lymphoma (Murphy stages II, III, and IV) were eligible for treatment with a multi-drug rotating chemotherapy schedule. This schedule was intensive and included early treatment directed at the central nervous system but was of only six months' duration and fairly inexpensive compared with schedules recently advocated for use in the developed world. Some patients had 'debulking' abdominal surgery, but no radiation treatment was used. There were a number of complications related to early treatment, some of them fatal, but of 13 patients entering complete remission 12 are long term survivors who are free of disease and, hopefully, cured. These results represent a substantial improvement over our experience before 1982 (6.9% survival). A similar treatment approach might be adopted by other centres, especially those in developing countries where cancer accounts for a rising proportion of childhood death but whose resources are limited.

Epstein-Barr virus status and tumour cell phenotype in sporadic Burkitt's lymphoma

Burkitt's lymphoma (BL) biopsy cells and derived cell lines can be grouped according to their patterns of reactivity with 6 selected monoclonal antibodies (MAbs) against B cell-associated surface antigens. Group I cells react only with MAbs J5 and 38.13, recognising the common acute lymphoblastic leukaemia antigen and a BL-associated antigen respectively; group II cells react with J5 and 38.13 and with one or more of a set of MAbs (Ki-24, MHM6, AC2, Ki-1) against "lymphoblastoid" antigens; group III cells react only with these anti-"lymphoblastoid" MAbs. Tumour biopsy cells from 17 cases of sporadic BL, 9 positive for the Epstein-Barr (EB) virus genome and 8 negative, have been analysed during the process of cell line establishment in vitro. In early passage the EB virus-negative BL cells showed either a group I phenotype or gave an additional reactivity with MAb Ki-24 which placed them in group II; these phenotypes remained essentially stable with continued growth of the cell lines for up to 50 passages. By contrast the EB virus-positive BL cells were much more susceptible to phenotypic change in vitro. Although such cells displayed a group I or group II phenotype in early passage, many of the lines soon moved into group III whilst retaining the karyotypic markers indicative of their malignant origin. These observations suggest that a resident EB virus genome can drive the in vitro progression of BL cells towards a more "lymphoblastoid" phenotype. This was confirmed in subsequent experiments where virus-negative BL cell lines were converted to EB virus positivity by in vitro infection. Clearly, therefore, phenotypic analysis of long-established lines can lead to false distinctions being drawn between the EB virus-positive and -negative forms of sporadic BL; both may derive from the same sub-population of target B cells in vivo.