Suboptimal outcome for patients with biliary rhabdomyosarcoma treated on low‐risk clinical trials: A report from the Children's Oncology Group

• Published in: Pediatric blood & cancer 2021-04, Vol.68 (4), p.e28914-n/a
• Main Authors: Aye, Jamie M., Xue, Wei, Palmer, Joshua D., Walterhouse, David O., Arnold, Michael A., Heaton, Todd E., Venkatramani, Rajkumar
• Format: Article
• Language: English
• Subjects: biliary rhabdomyosarcoma; Biliary tract; Biliary Tract Neoplasms - drug therapy; Biliary Tract Neoplasms - radiotherapy; Biliary Tract Neoplasms - surgery; Biliary Tract Neoplasms - therapy; Chemotherapy; Child; Child, Preschool; Children; Children & youth; Clinical trials; Disease Management; Female; Hematology; Humans; Male; Neoplasm, Residual - etiology; Oncology; Pediatrics; Radiation therapy; radiotherapy; Radiotherapy, Adjuvant; Rhabdomyosarcoma; Rhabdomyosarcoma - drug therapy; Rhabdomyosarcoma - radiotherapy; Rhabdomyosarcoma - surgery; Rhabdomyosarcoma - therapy; surgery; Survival; Treatment Outcome; Tumors
• ISSN: 1545-5009; 1545-5017; 1545-5017
• DOI: 10.1002/pbc.28914

Background Biliary rhabdomyosarcoma (RMS) is the most common biliary tumor in children. The biliary tract is classified as a favorable primary site. Therefore, patients with localized biliary RMS were included in two consecutive low‐risk studies, D9602 and ARST0331, by the Children's Oncology Group (COG). The outcome for these patients treated with low‐risk therapy has not been reported. Procedure Patients with biliary RMS enrolled on COG low‐risk trials D9602 or ARST0331 were analyzed. All patients received systemic chemotherapy and those with Group II (microscopic residual) or Group III (macroscopic residual) disease received 36‐50.4 Gy adjuvant radiotherapy (RT). Delayed primary excision (DPE) was allowed on both studies. Results Seventeen patients with biliary RMS were treated on D9602 (n = 7) or ARST0331 (n = 10). Median age was 3.5 years (range 1.7‐10.3). Ten (59%) patients had tumors >5 cm and 14 (82%) had Group III disease. Fifteen (88%) patients received RT. The 5‐year event‐free survival (EFS) and overall survival (OS) were 70.6% (95% confidence interval [CI]: 46.9‐94.3%) and 76.5% (95% CI: 54.6‐98.4%), respectively. The majority of patients (80%) who received RT did not have disease recurrence while both patients who did not receive RT had local relapse. Five (36%) of 14 patients with Group III disease underwent DPE; two experienced a local relapse. In the nine patients without DPE, two developed local relapse. Conclusions Patients with localized biliary RMS treated on low‐risk studies had suboptimal outcomes. These patients may benefit from therapy on intermediate‐risk studies.