Ethnicity and characteristics of Hodgkin lymphoma in children

To identify ethnic group differences in the prognostic of Hodgkin lymphoma (HL) in South African children.

In order to create a larger database, cases were pooled from two South African hospitals: Tygerberg in the Western Cape and Bloemfontein Academic Complex in Free State. Self-assigned ethnicity was used to allocate the children to the following groups: black, white, and colored (historical descendants of couples of distinct ethnicity, the "Cape colored" are the largest population group in Western Cape). Retrospective data over 21 years were obtained from the tumor registry. Age at presentation, sex, ethnic group, stage, histological type, treatment protocol, event-free survival interval, and mortality were analyzed. The statistical significance of the findings was tested using the chi-square, Mann-Whitney U, and Kruskal-Wallis tests, as indicated.

The study population of 138 comprised 78 black (56.5%), 38 colored (27.5%), and 22 white (16%) children under 15 years of age. There was a 3:1 predominance of the male gender. The median age at diagnosis was 8 years 11 months. Black patients presented at the youngest age (median 103 months), whereas white patients were the oldest at presentation (median age 133 months; P = 0.04).Forty-five percent of all patients were seen in stage 2. Black and colored patients presented with significantly more advanced stage disease (P = 0.04) than whites. B symptoms were evenly distributed among ethnic groups; they increased the mortality ratio from 10% to 33% (P = 0.0019). Histologically, mixed cellularity was seen in 50% of the black children, while nodular sclerosis was found in 50% of whites. The overall survival rate is 79%, with 68% in whites, 84% in patients of mixed ethnicity, and 79% in blacks (P = 0.35).

White children had the worst HL prognosis in this series, in spite of a less advanced stage at presentation.