title: The essential role of radiotherapy in the treatment of Merkel cell carcinoma: a study from the Rare Cancer Network.
abstract: OBJECTIVE
  To evaluate the role of postoperative radiotherapy (RT) in Merkel cell carcinoma (MCC).
  
  
  METHODS
  A retrospective multicenter study was performed in 180 patients with MCC treated between February 1988 and September 2009. Patients who had had surgery alone were compared with patients who received surgery and postoperative RT or radical RT. Local relapse-free survival (LRFS), regional relapse-free survival (RRFS), and distant metastasis-free survival (DMFS) rates were assessed together with disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) rates.
  
  
  RESULTS
  Seventy-nine patients were male and 101 patients were female, and the median age was 73 years old (range, 38-93 years). The majority of patients had localized disease (n = 146), and the remaining patients had regional lymph node metastasis (n = 34). Forty-nine patients underwent surgery for the primary tumor without postoperative RT to the primary site; the other 131 patients received surgery for the primary tumor, followed by postoperative RT (n = 118) or a biopsy of the primary tumor followed by radical RT (n = 13). Median follow-up was 5 years (range, 0.2-16.5 years). Patients in the RT group had improved LRFS (93% vs. 64%; p < 0.001), RRFS (76% vs. 27%; p < 0.001), DMFS (70% vs. 42%; p = 0.01), DFS (59% vs. 4%; p < 0.001), and CSS (65% vs. 49%; p = 0.03) rates compared to patients who underwent surgery for the primary tumor alone; LRFS, RRFS, DMFS, and DFS rates remained significant with multivariable Cox regression analysis. However OS was not significantly improved by postoperative RT (56% vs. 46%; p = 0.2).
  
  
  CONCLUSIONS
  After multivariable analysis, postoperative RT was associated with improved outcome and seems to be an important component in the multimodality treatment of MCC.
authors.affiliation: Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Switzerland. pirus.ghadjar@insel.ch
authors.forename: Pirus
authors.initials: P
authors.lastname: Ghadjar
authors.forename: Johannes H
authors.initials: JH
authors.lastname: Kaanders
authors.forename: Philipp
authors.initials: P
authors.lastname: Poortmans
authors.forename: Renata
authors.initials: R
authors.lastname: Zaucha
authors.forename: Marco
authors.initials: M
authors.lastname: Krengli
authors.forename: Jean L
authors.initials: JL
authors.lastname: Lagrange
authors.forename: Orhan
authors.initials: O
authors.lastname: Özsoy
authors.forename: Tan D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
authors.forename: Adele
authors.initials: A
authors.lastname: Baize
authors.forename: Noureddine
authors.initials: N
authors.lastname: Boujelbene
authors.forename: Timothy
authors.initials: T
authors.lastname: Collen
authors.forename: Luciano
authors.initials: L
authors.lastname: Scandolaro
authors.forename: Michel
authors.initials: M
authors.lastname: Untereiner
authors.forename: Hadassah
authors.initials: H
authors.lastname: Goldberg
authors.forename: Gianfranco A
authors.initials: GA
authors.lastname: Pesce
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Anacak
authors.forename: Esther E
authors.initials: EE
authors.lastname: Friedrich
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Aebersold
authors.forename: Karl T
authors.initials: KT
authors.lastname: Beer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D011182:Postoperative Care; D035583:Rare Diseases / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012044:Regression Analysis; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery