title: Age-related toxicity in patients with rhabdomyosarcoma: a report from the children's oncology group.
abstract: On the Fourth Intergroup Rhabdomyosarcoma study, older children experienced excessive neurotoxicity, whereas younger children had increased myelosuppression. The purpose of this study was to determine whether the same pattern of toxicity was seen on the successor study when use of growth factor was required and dosing of chemotherapy was different by performing a retrospective cohort analysis on patients treated on Children's Oncology Group protocol D9803. Toxicity data were analyzed by stratifying children into 4 age groups. The frequency of grade 3/4 neurotoxicity, myelosuppression, infection, and mucositis was predicted for each age group. The cumulative doses of vincristine and cyclophosphamide administered were measured as percent of protocol-prescribed dose. Adolescents (aged 15+) were more likely to experience neurotoxicity compared with younger patients (odds ratio, 3.6; P<0.0001). There was no difference in myelosuppression, infection, or mucositis. The mean percent protocol-prescribed doses administered for vincristine and cyclophosphamide did not differ much by age group. Adolescents experienced more neurotoxicity with vincristine compared with younger patients. No differences in other toxicities were observed between age groups. As adolescents received at least 85% of protocol-prescribed doses of vincristine, it is difficult to attribute the poorer survival in this age group to inadequate protocol-delivered therapy.
authors.affiliation: Departments of *Pediatric and Adolescent Medicine †Statistics and Informatics, Mayo Clinic, Rochester MN ‡Preventive and Societal Medicine, University of Nebraska Medical Center, Omaha, NE §Stanford University School of Medicine, Stanford, CA ∥Division of Pediatric Surgery, East Carolina University, Greenville, NC.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Altaf
authors.forename: Felicity
authors.initials: F
authors.lastname: Enders
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lyden
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Donaldson
authors.forename: David
authors.initials: D
authors.lastname: Rodeberg
authors.forename: Carola
authors.initials: C
authors.lastname: Arndt
mesh_terms: D000293:Adolescent; D000367:Age Factors; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000633:toxicity; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000633:toxicity; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007223:Infant; D007239:Infections / Q000209:etiology; D008297:Male; D052016:Mucositis / Q000139:chemically induced; D020258:Neurotoxicity Syndromes / Q000209:etiology*; D012189:Retrospective Studies; D012208:Rhabdomyosarcoma / Q000188:drug therapy*; D012983:Soft Tissue Neoplasms / Q000188:drug therapy*; D014750:Vincristine / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D018906:Antineoplastic Agents, Alkylating; D000972:Antineoplastic Agents, Phytogenic; D014750:Vincristine; D003520:Cyclophosphamide