Childhood malignant tumours in Papua New Guinea

Burkitt lymphoma in Papua New Guinea—40 years on

BACKGROUND

Burkitt lymphoma is common in tropical Africa and Papua New Guinea, where it has been reported to account for 16% of all childhood malignancies.

AIM

This study aimed to compare the geographical distribution of recent cases and their anatomical site of presentation with findings from previous studies, and to determine survival using the current treatment protocol.

METHODS

The study included all cases of Burkitt and Burkitt-like lymphoma in children up to 14 years of age diagnosed between January 1998 and December 2003.

RESULTS

Thirty-six children were diagnosed with Burkitt lymphoma, accounting for 50% of all lymphomas and 13% of all childhood malignancies. The median age was 6 years (interquartile range 4-8 years) and the male:female ratio was 8:1. Facial structures were the most commonly affected sites, accounting for 21 (58%) cases, followed by spinal involvement in three. The majority (89%) of patients came from malaria-holo-endemic, coastal PNG and three were from the highland region. The national incidence was 1.7/100,000 but provincial rates varied, the highest of 13.4/100,000 being in Gulf province. Only two of the 16 patients who received chemotherapy were known to be in remission at 12 months.

CONCLUSIONS

Burkitt tumour remains a common childhood malignancy in PNG. There is a need to improve diagnosis and reporting so that treatment can be started early. The most appropriate treatment regimen for use in PNG and other resource-poor countries remains to be determined.

Leukaemia in children in Papua New Guinea: an unusual pattern

We report data on 110 children aged <15 years diagnosed with leukaemia during two periods covering 13.25 years. The data sets were consistent. The reported incidence of leukaemia was low. Only 34 (31%) of the children were diagnosed with acute lymphoblastic leukaemia (ALL) compared with 54 (49%) children with acute myeloid leukaemia (AML). The overall mean (SD) age was 6.6 (3.5) years, 6.1 (3.5) for ALL and 6.9 (3.5) for AML. There was no evidence of an early childhood peak of ALL. The male : female ratio was 1.2 : 1 for all leukaemias, 1.3 for ALL and 1.25 for AML. Only eight (22%) of those diagnosed with ALL were classified as type L1. Our figures reflect a relative absence of the common (cALL) cell type in early childhood leukaemia and support the role of infection and its effect on the immune system in the aetiology of childhood leukaemia. Our data also revealed an unusually high proportion of chronic myeloid leukaemia (CML).

Paediatric head and neck lymphomas in Papua New Guinea: a review and analysis of 67 cases

A retrospective study of head and neck lymphomas in Papua Newguinean children between the age of 0 and 12 years for a 10-year period has been attempted. A total of 67 cases are recorded. This constitutes approximately 23% of all lymphomas seen during this period. There was a male predominance in all groups. Non-Hodgkin's lymphomas (NHL) comprised of 92% of which Burkitt's lymphomas (BL) predominate (64%). Almost 50% of these cases seen were in the age group of 5-8 years. In BL, cheek swelling and upper jaw involvement are the common modes of presentation, however, in 23% of cases advanced disease with multiple sites of involvement are noted. In other NHL cases, approximately 55% presented with cervical lymphadenopathy only, maxillary sinus was affected in four cases and orbit in two cases. Histological evaluation of NHL cases excluding BL revealed two high grade, nine intermediate grade and seven low grade tumours. Hodgkin's lymphoma (HL) comprised of 8%. All cases of HL presented with cervical lymphadenopathy. Standard therapeutic modalities for lymphomas with multidrug chemotherapy, surgery and radiotherapy were followed. Proper prognostic evaluation following the treatment had not been possible in view of poor patient compliance and lack of follow up.

International variations in the incidence of childhood soft-tissue sarcomas

In the study of international childhood cancer incidence coordinated by the International Agency for Research on cancer, soft-tissue sarcomas comprised between 4 and 8% of all cancers between 0 and 14 years of age. Among predominantly white populations, the age-standardised annual incidence rate (ASR) for all soft-tissue sarcomas was between 5 and 9 per million. The most common histological subtypes were rhabdomyosarcoma (ASR 4-7 per million) and fibrosarcoma, including other malignant fibromatous tumours (ASR 1-2 per million). In the United States the incidence of rhabdomyosarcoma for black girls was only half that for white girls, while the rates for boys were similar in the two ethnic groups; fibrosarcoma had a higher incidence among black people than white people for both sexes. Throughout most of Asia, soft-tissue sarcomas almost invariably had a total ASR below 6 per million, rhabdomyosarcoma and fibrosarcoma again being the most common histological types. In Africa, incidence rates could not generally be calculated, but there were substantial numbers of registrations for rhabdomyosarcoma and fibrosarcoma. The majority of cases of Kaposi's sarcoma were in African children, and in eastern and southern Africa where Kaposi's sarcoma is endemic among adult men it comprised 25-50% of soft-tissue sarcomas and 2-10% of all childhood cancers; the sex ratio (M/F) was 2.2:1, in contrast to the overwhelming male predominance among adults. Variations between ethnic groups in the incidence of rhabdomyosarcoma and fibrosarcoma, together with their occurrence in a number of heritable syndromes, suggest that genetic predisposition is important in their aetiology. There was little evidence for an environmental aetiology in rhabdomyosarcoma and fibrosarcoma but an infectious agent may be responsible for childhood Kaposi's sarcoma.

Malignant tumours in Omani children

In an effort to understand better the epidemiology of childhood cancer in Oman, a retrospective review of hospital-based biopsy-proven malignant tumours was undertaken. A total of 313 cases of malignant diseases in children between the ages of 0 and 12 years were diagnosed in Oman during the 5-year period from January 1988 to December 1992, inclusive. Leukaemias were the most commonly occurring malignancies (32.3%), followed by lymphomas (29%) and brain tumours (11.2%). The male:female ratio was 1.3:1. The commonest presenting age group was 2 years, the majority of which were leukaemias and lymphomas. Differences and similarities between Omani data and those from other countries are discussed.