Survival of patients with orbital and eyelid rhabdomyosarcoma treated on Children's Oncology Group studies from 1997 to 2013: A report from the Children's Oncology Group

Abstract

Background: Orbital rhabdomyosarcoma (ORMS) commonly presents as low-risk disease (stage 1, group I-III, embryonal RMS) with excellent outcome. Long-term follow-up of patients with low-risk ORMS and outcomes of less common subgroups of ORMS treated on recent Children's Oncology Group (COG) trials have not been reported.

Methods: Patients with ORMS enrolled on COG trials from 1997 to 2013 were identified. Demographic information and disease characteristics were collected. Outcomes were determined for the following subgroups: 1) low-risk ORMS, 2) resected (group I/II) low-risk ORMS, 3) non-low-risk ORMS, and 4) recurrent ORMS. Event-free survival (EFS) and overall survival (OS) were estimated using the Kaplan-Meier method. ResultsThe authors identified 218 patients with ORMS. Most tumors were embryonal/botryoid (n = 169; 77.5%), <5 cm (n = 213; 97.7%), group III (n = 170; 78.0%), and without lymph node involvement (N0; n = 215; 98.6%). For 192 patients with low-risk ORMS, the 10-year EFS and OS rates were 85.5% (95% confidence interval [CI], 77.0%-94.0%) and 95.6% (95% CI, 90.8%-100.0%), respectively. Those with group I/II low-risk ORMS (n = 5 in group I; n = 39 in group IIA) had 10-year EFS and OS rates of 88.0% (95% CI, 72.6%-100.0%) and 97.6% (95% CI, 90.0%-100.0%), respectively. Twenty-six patients with non-low-risk ORMS had 5-year EFS and OS rates of 88.5% (95% CI, 75.6%-100.0%) and 95.8% (95% CI, 87.7%-100.0%), respectively. For patients with recurrent ORMS, the 10-year OS rate from the time of recurrence was 69.4% (95% CI, 50.0%-88.8%).

Conclusions: Patients with ORMS had favorable long-term survival outcomes on COG studies from 1997 to 2013, including those who had both low-risk and non-low-risk disease. A significant proportion of patients with recurrent ORMS may achieve long-term survival.

Keywords: orbital; pediatric; rhabdomyosarcoma; sarcoma; survival.

FIGURE 1

Kaplan–Meier distribution for low-risk orbital rhabdomyosarcoma. (A) EFS and (B) OS are illustrated for COG trials D9602 (red) and ARST0331 (green). (C) EFS and (D) OS are illustrated for patients with group I/IIA low-risk orbital rhabdomyosarcoma. Estimated 10-year EFS and OS rates for each Kaplan–Meier curve are indicated at the bottom right in each graph. CI indicates confidence interval; COG, Children’s Oncology Group; EFS, event-free survival; OS, overall survival.

FIGURE 2

Kaplan–Meier distribution for non-low-risk and recurrent orbital rhabdomyosarcoma. (A) EFS and (B) OS are illustrated for non-low-risk orbital rhabdomyosarcoma, and (C) OS is illustrated for recurrent orbital rhabdomyosarcoma. The estimated 5-year EFS and OS rates for non-low-risk disease and the 10-year OS rate for recurrent disease are indicated at the bottom right in each graph. CI indicates confidence interval; EFS, event-free survival; OS, overall survival.