title: Patterns of failure for rhabdomyosarcoma of the perineal and perianal region.
abstract: OBJECTIVE
  To analyze prognostic factors and patterns of failure for rhabdomyosarcoma of the perineal and perianal region (PRMS), with an emphasis on radiation therapy for locoregional control.
  
  
  METHODS
  Detailed records of all 14 patients treated for PRMS at Memorial Sloan-Kettering Cancer Center between 1998 and 2012 were reviewed. The Kaplan-Meier method was used to assess the event-free survival (EFS) and overall survival (OS), and a competing-risks analysis was used to assess the cumulative incidence of local, regional, and distant failures.
  
  
  RESULTS
  Median age was 15.8 years (range, 1.1-31.9 years). High-risk features were identified: 9 of 14 patients (64%) had group 3 disease and 3 of 14 (21%) had group 4; 11 of 14 tumors (78%) were alveolar; 12 of 14 tumors (86%) were ≥5 cm; and 9 of 14 patients (64%) had involved lymph nodes (N1). Of those aged ≥10 years at diagnosis, 9 of 10 (90%) had alveolar histology, all had tumors ≥5 cm, and 8 of 10 (80%) presented with N1 disease. The rates of local, regional, and distant failure at 5 years were 17%, 31%, and 52%, respectively. Although 3 of the 4 patients with regional failure received nodal irradiation, only one of the nodal failures occurred in the radiation therapy field. The 5-year EFS was 33%, and OS was 39%. Age ≥10 years was associated with poor outcomes: EFS was 13% in patients aged ≥10 years, compared with 75% in those aged <10 years (P=.04); the OS was 13% in patients aged ≥10 years, compared with 100% in those aged <10 years (P=.04).
  
  
  CONCLUSIONS
  Patients with PRMS, especially those aged ≥10 years, present with poor prognostic features and continue to have poor outcomes. Given the high incidence of regional node recurrence, we recommend prophylactic ilioinguinal lymph node irradiation for all patients aged ≥10 years. For children aged <10 years, nodal evaluation is essential to determine the role for lymph node irradiation.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Casey
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Wexler
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Michael P
authors.initials: MP
authors.lastname: LaQuaglia
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Meyers
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York. Electronic address: woldens@mskcc.org.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Wolden
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D007085:Ilium; D007223:Infant; D007264:Inguinal Canal; D008198:Lymph Nodes / Q000473:pathology; D015182:Lymphatic Irradiation / Q000379:methods; D008207:Lymphatic Metastasis; D008297:Male; D010502:Perineum; D011379:Prognosis; D035583:Rare Diseases / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D018232:Rhabdomyosarcoma, Alveolar / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D018233:Rhabdomyosarcoma, Embryonal / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D016019:Survival Analysis; D017211:Treatment Failure; D047368:Tumor Burden; D055815:Young Adult