Children From Ethnic Minorities Have Benefited Equally as Other Children From Contemporary Therapy for Rhabdomyosarcoma: A Report From the Intergroup Rhabdomyosarcoma Study Group

Abstract

PURPOSE: To define the clinical characteristics of rhabdomyosarcoma (RMS) occurring in children from ethnic minorities and determine whether these children have benefited equally from advances in therapy. PATIENTS AND METHODS: This was a retrospective cohort analysis of children treated on the Intergroup Rhabdomyosarcoma Study Group protocols between 1984 and 1997. The clinical features and outcomes of 336 African-American children and 286 children from other ethnic minorities were compared with those of white children (n = 1,721). RESULTS: African-American, other ethnic group, and white children enjoyed similar 5-year failure-free survivals (FFS) of 61%, 61%, and 66%, respectively, P = .15. Compared with white children, nonwhite patients more often had (1) invasive, T2 tumors (P = .03); (2) stage 2 or 3 tumors (P = .003); (3) large tumors (more than 5 cm, P < .006); and/or (4) tumors with positive regional nodes (ie, N1, P = .002). Using Cox proportional hazards analysis, seven patient risk categories were defined with significant differences in outcome. This model was then used to search for other factors associated with FFS after adjusting for these risk categories. Only T stage and age remained associated with FFS (P = .001 and P < .001, respectively). After adjusting for T stage, risk category, and age, we explored the relationship of ethnic group to FFS and found that, compared with whites, the relative risk of failure was 1.14 for African-American patients and 1.2 for other ethnic minority patients, values that are not significantly different. CONCLUSION: Patients from ethnic minority groups more often have larger, invasive tumors with positive lymph nodes. Nevertheless, they have benefited as equally as white children from the dramatic progress in therapy of RMS.