Improved outcome for patients with middle ear rhabdomyosarcoma: a children's oncology group study

The goal of this study was to define the clinical features and optimal therapy for children and adolescents with middle ear (ME) rhabdomyosarcoma (RMS).

We reviewed demographic data, clinical features, therapy (including chemotherapy, surgery, and radiation), and outcome for the 179 eligible patients with ME RMS who were enrolled onto Intergroup Rhabdomyosarcoma Studies (IRS) I through IV or pilot studies between November 1972 and December 1997.

Most patients were younger than 10 years old (90%), and 63% were male. Because of the parameningeal location, most tumors were not resected before chemotherapy (group I, < 1%; group II, 4%; group III, 84%; group IV, 12%). Although most tumors were locally invasive (T2, 89%), the majority were small (< or = 5 cm, 66%), lacked nodal metastases (N0, 86%), and had embryonal histology (85%). The 5-year failure-free survival (FFS) and overall survival (OS) estimates were 67% and 72%, respectively. Both FFS and OS improved significantly over the course of IRS I through IV (3-year FFS and OS: IRS-I, 42% and 42%; IRS-II, 70% and 74%; IRS-III, 65% and 72%; IRS-IV pilot, 81% and 96%; IRS-IV, 88% and 88%, P <.001). Lower clinical group or stage and smaller tumor size were associated with better outcome. Age, sex, tumor invasiveness, and nodal metastases were not predictive of outcome.

Patients with ME RMS generally present with small, unresectable, invasive tumors at a site traditionally considered prognostically unfavorable. Nevertheless, such patients have benefited markedly from improvements in multimodal, risk-based therapy during the course of IRS I through IV, and with contemporary therapy, most are cured.