prof Borgstein

Burkitt lymphoma (BL) accounts for 50% of childhood cancer in Malawi. Lack of resources precludes the use of new successful treatment approaches such as the LMB 89 group B protocol, which cures >80% of children with stage III BL with high dose chemotherapy and matching supportive care. Our objective was to achieve a good cure rate in Murphy stage I-III BL with manageable toxicity in Malawi at a drug cost of <1000 US dollars per patient. The intensity and toxicity of the LMB 89 group B protocol was reduced and adapted to Malawi realities. All stages received the same treatment. Children with suspected BL in the period July 1997-November 1999 were subjected to abdominal ultrasound, a tumor biopsy and/or fine needle aspirate (FNA) and bone marrow (BM), cerebrospinal fluid (CSF), and peripheral blood examination. HIV seropositive children were excluded. Endpoints are projected event free survival (EFS) at minimum 1 year, blood and gastro-intestinal tract toxicity, and risk for and severity of infections. Forty-four children were eligible for treatment and analysis. Their median age was 7.2 years, M:F ratio 1.4:1 with 10 stage I, 5 stage II, and 29 stage III patients. Projected Kaplan-Meier EFS for all was 57% (CI 41-73) at 1 year with 90% EFS in stage I and 52% EFS in stage III. The survival curve remained stable at 500 days. Toxicity and delays in appropriate supportive care contributed to ten deaths during treatment. Local recurrent tumor caused five and CNS recurrence one death. Two children died from progressive disease. The incidence of severe (grade 3 and/or 4) hematologic toxicity varied from 13% to 36%, gastro-intestinal toxicity (GIT) from 2% to 17%, and infections from 7% to 41% per chemotherapy module. It is possible to administer less intense and less costly multiagent chemotherapy to children with BL in a developing society with acceptable EFS rates. Adequate supportive care of the at-times associated severe toxicity must be made available to better the results.

We previously reported 57% 12-month event free survival (EFS) in Malawian children with stage I to III Burkitt lymphoma (BL) with an intermediate dose chemotherapy protocol lasting 77 days. This protocol was shortened to 42 days and evaluated in children with stage I to IV disease for EFS and toxicity. All Malawian children admitted to Queen Elizabeth Central Hospital, from 03/08/2000 to 12/03/2002 with confirmed BL were eligible. A fine needle aspirate, bone marrow aspirate, cerebrospinal fluid cytology, haemoglobin (Hb), white cell count (WCC), malaria smear, ELISA for HIV, and abdominal ultrasound were performed routinely. Murphy staging was used. The first dose of chemotherapy (COP1) consisted of 300 mg cyclophosphamide (CPM), 1 mg vincristine, and 60 mg prednisone given on day 1 and followed by COP2 on day 8 (only for patients with larger tumour volumes, stage III or IV disease). The vincristine dose in COP2 was 2 mg. COMP1 and 2 given on days 22 and 36 consisted of 500 mg CPM, 2 mg vincristine, 60 mg prednisone, and 2 g methotrexate. All doses were calculated per body surface area. Intrathecal methotrexate and hydrocortisone were given with COP1 and 2. Forty-two patients, 30 boys and 12 girls median ages 6 and 7.5 years, respectively, had Murphy stage I(n5), II(n8), III(n21), and IV(n8) disease. The face was involved in 74%, abdomen in 55%, bone marrow in 14%, kidneys in 24%, and 12% had paraplegia. Fourteen children died during or shortly after completion of chemotherapy. Three of these were disease related. Twelve patients suffered a local relapse after 57-328 days, and one a CNS relapse at 76 days. The projected EFS at 12 months is 50% in stage I, 50% in stage II, 24% in stage III, 25% in stage IV, and 33% for all patients. The cumulative mean dose of CPM was 62 mg/kg in survivors and 64 mg/kg in children who relapsed. One third of patients experienced significant marrow suppression, and infections after COMP1. Thirty-three percent of children are in first remission at 12 months. The morbidity and mortality of treatment was high. The high relapse rate in all stages may be due to the low cumulative dose of CPM.

Gastro-oesophageal reflux (GER) in neurologically impaired children often causes feeding problems and complications of oesophagitis and is frequently resistant to medical treatment. Fifty neurologically impaired children underwent anterior gastropexy as anti-reflux operation, combined with gastrostomy in 23, between 1976 and 1992. There was no operative mortality. There were 25 early complications in 14 patients and 9 late complications in 9 patients. Twelve patients needed 17 re-operations for delayed gastric emptying [4], intestinal obstruction [3], para-oesophageal hernia [3], oesophageal stenosis [4], and recurrent GER, revision of gastrostomy, subphrenic abscess (one each). Nine patients died during the follow up period. Death in two children was related to the operation (incarcerated para-oesophageal hernia and blow-out of the stomach). Out of 41 survivors, the operation was judged successful in 35. It is concluded that antireflux operations in neurologically impaired children carry a high risk of complications. Preoperative identification of risk factors is not possible. The improvements in the quality of life achieved in the majority of patients outweigh the risks.

To study transmission patterns of human herpesvirus-8 (HHV-8) (Kaposi's sarcoma-associated herpesvirus) in families in Malawi, nucleotide sequences derived from two hypervariable loci of the HHV-8 genome, the V1 and V2 regions of open reading frame K1 (K1/V1 and K1/V2, respectively), were amplified from blood and mouth rinse samples of 22 patients with treated and untreated Kaposi's sarcoma (KS) and their first-degree relatives (n=67). In patients with KS, vincristine therapy was significantly associated with non-detectability of circulating, but not oral, K1/V1 DNA. Intra-familial K1/V1 phylogenetic comparisons of eight families were possible. Both identical and non-identical sequences were observed between family members, suggesting transmission of HHV-8 along both intra- and extra-familial transmission routes.

Intra-familial transmission of Kaposi's sarcoma associated herpesvirus (KSHV) is likely to occur in geographical regions where KSHV infection is highly endemic. Transmission has been studied previously indirectly using serological techniques, however direct documentation of specific transmission routes has yet to be reported. The internal repeat domain (IRD) of the KSHV opening reading frame (ORF) 73 was shown previously to exhibit restriction-fragment length polymorphism (RFLP). Analysis of such polymorphism was undertaken using nested ORF 73 IRD PCR products derived from the blood and mouth rinse samples of individuals in Malawian family groups. The resulting RFLP patterns were unique to an individual and could be compared between family members. In three of eight families studied, identical RFLP patterns were recovered from family members; in the remaining five families, dissimilar RFLP patterns were revealed. Results from RFLP analysis were compared to sequencing data recovered from family members for the first variable region of the hypervariable KSHV ORF K1. Patterns of intra- and extra-familial transmission inferred from ORF K1 sequencing data were corroborated mainly using ORF 73 IRD RFLP analysis.

Primary BL in Malawian children has a very high frequency association, approaching 100%, with the human herpesvirus EBV. A detailed study carried out on viral gene expression in these tumours, using both fresh material and methanol-fixed FNAs, showed, contrary to prediction, that most belong to a variant "class II" latency category, with lytic cycle-related genes also expressed. That is, in addition to EBNA1 expression, membrane proteins (LMP1/2A), immediate early (BZLF1) and early (IR2 and IR4) genes, a putative viral oncogene (BARF1), CST (BART) antisense transcripts and the viral bcl-2 homologue are expressed in a high proportion of the BLs. Most, but not all, express the small viral (EBER) RNAs. Two other significant observations were made: (i) in addition to expression of cellular cytokine (IL-10) transcripts in all tumours investigated, the normally silent viral IL-10 homologue was expressed in some tumours; (ii) whereas EBNA1 expression from its restricted Qp promoter was generally observed, the nonrestricted Cp/Wp promoter was also active in some tumours. Viral gene expression in the Malawian [endemic (e)] BLs appears to be more promiscuous than predicted from other studies, but expression accords with the cytopathologic picture of eBLs as a rapidly proliferating cell population accompanied by considerable necrosis, and a clinically diverse disease. A small-scale study of relapse Malawian BLs revealed a different picture of viral association, more akin to systemic BL than eBL, where EBV appears to be absent or present only at very low levels. The significance of these findings is considered.