Malignant neoplasms in Jordanian children

Malignant lymphoma in Jordan: a retrospective analysis of 347 cases according to the World Health Organization classification

BACKGROUND

Most studies describing the subtypes of lymphoma in Jordan were carried out in the 1980s at a time when immunohistochemical facilities were unavailable. Using a database established after immunohistochemical studies were introduced, we determined the frequency of the various types of nodal and extranodal lymphomas in the adult and paediatric Jordanian population. We also assessed the incidence of bone marrow involvement at the initial presentation for each lymphoma type.

METHODS

A retrospective analysis of the histopathological subtypes of various lymphomas was conducted on all primary lymphoma cases diagnosed during a 3-year period between January 2001 and December 2003.

RESULTS

Of 347 patients included in the study, 78.4% had non-Hodgkin's lymphoma (NHL) and 21.6% had Hodgkin's lymphoma (HL). In the NHL group, diffuse large B-cell lymphoma was the most common (28.2%) followed by follicular lymphoma (15.6%). In the HL group, the nodular sclerosis variant was the most frequent (7.8%) followed by the mixed cellularity type (5.5%). Of all the lymphoma cases, the highest incidence of marrow involvement was seen in patients with lymphoplasmacytic lymphoma. Forty-nine patients were children (age <15 years) in whom Burkitt's lymphoma (15 cases) and HL (14 cases) were the commonest subtypes. One-hundred six patients with primary extranodal lymphomas (ENL) accounted for 30.5% of all lymphomas.

CONCLUSIONS

There is a higher incidence of NHL in Jordan compared with other series in the Middle East. Among the various lymphomas, diffuse large B-cell lymphoma is the most commonly encountered lymphoma in adults. Burkitt's lymphoma and Hodgkin's disease are the most frequent childhood lymphomas, followed closely by lymphoblastic lymphoma.

The incidence of childhood cancer in Jordan: a population-based study

BACKGROUND

Marked variations in the incidence of particular types of childhood cancer exist between countries. We report on the geographic variation in the occurrence of childhood cancer in Jordan.

MATERIAL AND METHODS

Cases were identified from the Jordan National Cancer Registry. We collected data on age, sex, type, primary site, and stage of cancer. Tumor topography and morphology were coded according to the accepted international standard. For all cases registered, 95.2% were histologically diagnosed. Incidence rates were calculated as annual rates per million population. The denominator is the 1997 estimate of the childhood population at ages 0-4, 5-9, and 10-14 years.

RESULTS

There were 646 registered primary malignant neoplasms during the three-year study period (1996-1998). The annual incidence rate for all types of cancer combined was 113 per million children. The rate among children less than 5 years of age was 134.5 per million, for 5-9 years it was 97.8 per million, and for 10-14 years it was 104.1 per million. Overall, the age-standardized annual incidence rate was 113.8 per million. The most common diagnostic group was leukemia, accounting for more than a third of all cases, followed by brain tumors and lymphoma. The highest rate was in the capital, Amman.

CONCLUSION

The pattern of childhood cancer in Jordan seems to be generally similar to other countries in the region, particularly the observed excess of lymphoma. Geographical variations in childhood cancer exist in Jordan and could be partly explained on the basis of lower detection or reporting, or both, in certain locations.

Patterns of childhood solid tumor incidence in northern Israel, 1973-1990

A retrospective analysis of 515 pediatric cancer cases diagnosed over 18 years, 1973-1990, showed an annual incidence of pediatric solid tumors in northern Israel of 77.1 per million, somewhat lower than previously reported. Lymphomas predominated over central nervous system (CNS) neoplasms, suggesting an Afro-Asian rather than a Western pattern. Jewish and non-Jewish children were at approximately equal risk (1:07:1.0) for the nonleukemic cancer. However, there was a notably higher frequency in males than females (1:42:1.0) and in Ashkenasi Jews as compared to either Sephardi Jews (1.25:1.00) or non-Jews (1.23:1.0). Ethnic, age, and sex predispositions for particular types of malignancy were also noted. Non-Jews tended to have lymphomas or retinoblastomas and Sephardi Jews were predisposed to soft tissue sarcomas. Ashkenasi Jews tended to manifest CNS tumors, retinoblastoma, and osteosarcoma. Children under 5 years showed Burkitt's lymphoma and neuroblastoma, whereas the older group tended to have Hodgkin's lymphoma. Boys were more vulnerable to non-Hodgkin's lymphoma, medulloblastoma, neuroblastoma, and rhabdomyosarcoma, and girls were subject to higher incidences of bone, gonadal, germ cell, and epithelial tumors, as well as to astrocytoma. The implications for genetic or environmental contributions to several cancers are considered in conjunction with ethnic or gender predisposition to those cancers.

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.

International variations in the incidence of neuroblastoma

The International Agency for Research on Cancer has coordinated a worldwide study of childhood cancer incidence, with data from over 50 countries. We present here the results for neuroblastoma. In predominantly white Caucasian populations the age-standardized rate was 7-12 per million, and 6-10% of all childhood cancers were neuroblastomas. Rates were highest in the first year of life (25-50 per million, 30% of total neuroblastoma incidence), and decreased with age to 15-20 per million (50% of the total) at age 1-4, 2-4 per million (15%) at 5-9 and 1-1.5 per million (5%) at 10-14. In the United States, black children had an incidence of 8.5 per million compared with 11.5 among Whites; Blacks tended to be older than Whites at diagnosis. The highest rate in Africa was in Bulawayo, Zimbabwe (8.0 per million) and the lowest in West Nile, Uganda, with no cases registered. Incidence in Israel was similar to that in many white populations, with Jews having a particularly high rate. In other parts of West Asia neuroblastoma had a low relative frequency, suggesting that incidence is low. Rates were also low throughout much of southern and eastern Asia, including India and China. Incidence in Japan was somewhat higher, though less than in Western countries, with the deficit most pronounced in the first year of life; these data relate to the period before mass screening of infants for neuroblastoma in the regions concerned. Incidence was generally higher in regions and among ethnic groups enjoying a higher standard of living, though previous studies within single countries had suggested that neuroblastoma is more common among less affluent groups. Blacks in Africa and the United States may have a weaker genetic predisposition to neuroblastoma, but some of the deficit in many developing countries is likely to be due to under-diagnosis.

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.

Malignant tumors in children of northeastern Zaire. A comparison of distribution patterns

In an effort to better understand the epidemiology of cancer in Zaire, a retrospective review of biopsy-proven malignant tumors was undertaken. Of 188 biopsies taken from children aged 0-15 years over a 4.5 year period, 73 (39%) revealed malignancy. Fifty-six percent of patients with malignant tumors were boys. Lymphoma was the most common tumor (28 patients, 15 with Burkitt's Lymphoma). Sarcoma (15 patients), carcinoma (8 patients), Wilms' Tumor (6 patients), and retinoblastoma (5 patients) were also seen. Lymphomas were most heavily represented in the first 5 years of life, while sarcoma and carcinoma accounted for most of the malignancies in children after 10 years of age. Lymphomas and sarcomas are relatively more common in Zaire than in North America and Europe, while leukemia and central nervous system tumors are notably less common in Zaire. In view of current limitations on health care in rural Zaire, cancer care should be directed toward early diagnosis, quick referral for appropriate surgical care, and use of the limited arsenal of chemotherapy.

Diagnostic value of cervical lymph node biopsy: a pathological study of 596 cases

During a 10-year period (1976-1985), a total of 596 cervical lymph node biopsies for diagnostic purposes were performed at our institution. Thirty-five percent of these nodes were involved with malignant lymphoma, and 20.5% showed metastatic deposits. Nondiagnostic reactive hyperplastic changes were noted in 23% of the cases. Several other inflammatory and neoplastic conditions were encountered. Comparison of our data with several series from different countries with review of relevant literature are presented.