Lymphatic metastases with childhood rhabdomyosarcoma. A report from the Intergroup Rhabdomyosarcoma Study

A review of 1415 patients without distant metastasis from the Intergroup Rhabdomyosarcoma Study (IRS) I and II revealed an overall 10% incidence of identified lymphatic spread at diagnosis, whereas 81 of 592 children with localized rhabdomyosarcoma who had grossly complete resection (and therefore with more complete pathologic data) had histologically proven lymphatic spread (14%). The percentage of patients in this latter group with nodal metastases was highest for the prostate (41%), paratesticular sites (26%), and genitourinary sites overall (24%). Sites with a small percentage of proven lymphatic involvement were the orbit (0%), nonorbital head and neck sites (7%), and truncal sites (3%), whereas the percentage of patients with nodal metastases from extremity lesions was 12%. The primary tumor mean diameter was significantly larger in the group with nodal metastases, but there was no evidence of a relationship between lymphatic spread and age, sex, or histologic subtype. Patients with lymph node metastases who had resection had a poorer survival rate (logrank P value = 0.001), with a 3-year survival estimate of 54%, compared with 78% for patients without lymphatic metastases. Patients with extremity lesions and positive lymph nodes also did poorly when compared with patients with normal nodes (P = 0.006), and a similar observation was made for patients with paratesticular sarcoma (P = 0.06).