Factors Affecting Prognosis in Localized Paratesticular Rhabdomyosarcoma
In a study reported in the Journal of Clinical Oncology, Walterhouse et al found that age ≥ 10 years at diagnosis and tumor size > 5 cm are adverse prognostic features in localized paratesticular rhabdomyosarcoma.
Study Details
The study was a pooled analysis of data from North American and European cooperative groups, assessing the effect of 9 demographic variables and 4 treatment modalities on event-free survival and overall survival in 12 cooperative group studies. A total of 842 patients with localized paratesticular rhabdomyosarcoma enrolled from 1988 to 2013 were included in the analysis.
Factors Affecting Prognosis
Patients aged ≥ 10 years at diagnosis were more likely vs younger patients to have tumors that were > 5 cm, enlarged nodes (N1), or pathologically involved nodes (all P ≤ .05). With a median follow-up of 7.5 years, estimates for 5-year event-free survival and overall survival among all patients were 87.7% and 94.8%.
Cooperative group, era of enrollment, age category, tumor size, Intergroup Rhabdomyosarcoma Study group, and T stage were all significantly associated with event-free survival (all P ≤ .05). Surgical assessment of regional nodes (performed in 23.5% of patients, usually those aged ≥ 10 years or with suspicious or N1 nodes) was the only treatment variable associated with improved event-free survival on univariate and multivariate analyses (P ≤ .05 each) in patients aged ≥ 1 year.
In proportional hazards regression multivariate models, era of enrollment, age (hazard ratio [HR] = 0.37, P < .001, for 1–9 vs ≥ 10 years), tumor size (HR = 2.42, P < .001, for > 5 vs ≤ 5 cm), and surgical assessment of regional nodes were significantly associated with event-free survival and era of enrollment, age (HR = 0.31, P < .001, for 1–9 years vs ≥10 years), tumor size (HR = 3.60, P = .001, for >5 vs ≤ 5 cm), and histology were significantly associated with overall survival.
The investigators concluded, “Localized [paratesticular rhabdomyosarcoma] has a favorable prognosis. Age ≥ 10 years at diagnosis and tumor size larger than 5 cm are unfavorable prognostic features. Surgical assessment of regional nodes is important in patients aged ≥ 10 years and in those with N1 nodes as it affects [event-free survival].”
The study was supported by grants from the National Cancer Institute, St Baldrick’s Foundation, and a grant from the WWWW (QuadW) Foundation to the Children’s Oncology Group.
David O. Walterhouse, MD, of the Ann & Robert H. Lurie Children’s Hospital of Chicago, is the corresponding author for the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
