Retroperitoneal node biopsy in paratesticular rhabdomyosarcoma

Abstract

Retroperitoneal lymph node dissection (RPLND) was used in 121 Intergroup Rhabdomyosarcoma Study (IRS) III patients with nonmetastatic paratesticular (PT) rhabdomyosarcoma (RMS) to assess retroperitoneal lymph node (RPLN) involvement so as to determine the need for x-ray therapy (XRT). Clinical node evaluation (CNE) was accomplished by a computed tomography (CT) scan in 105 and a sonogram in six. Pathological node evaluation (PNE) was performed in 113: lymphadenectomy (9 bilateral, 85 unilateral) and biopsy in 19. Vincristine and actinomycin D were used for 1 year postoperatively in 89%; all patients who had positive PNE received RPLN XRT. This study compares CNE with PNE and evaluates predictors of relapse and survival. Findings: There were clinically negative nodes (cN0) in 81% of the 121 patients. Among cN0 patients, 14% had positive nodes (pN1). Of the clinically positive (cN1) patients, 94% had pN1. RPLN relapse occurred in only two of the 121 patients. Initially both had cN0 and one had PNE that was negative. For all 121 patients, the 5-year survival was 91%. For cN0 patients, the 5-year survival was 96% compared with 69% for cN1 patients ( P < .001). Among the children in whom treatment failed, nodes were cN1 in 5 of 11 (45%) compared with 15 of 107 (14%) in those whose treatment did not fail ( P < .008). Conclusions: (1) Results of RPLN imaging studies were negative in 81% of patients with PT RMS (specificity 99%, sensitivity 57%). (2) RPLN recurrence is uncommon (even when RPLN are initially involved) if regional XRT and appropriate chemotherapy are used. (3) RPLN biopsy is not necessary to confirm positivity in patients with clinically positive nodes. (4) Node positivity is associated with decreased patient survival and helps identify patients who have an increased risk for relapse and death.