title: Natural history of merkel cell carcinoma following locoregional recurrence.
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine malignancy with an ill-defined natural history following locoregional recurrence.
  
  
  METHODS
  This is a retrospective review of patients with MCC diagnosed at the Mayo Clinic from 1981 to 2008. For each outcome (subsequent locoregional recurrence, distant recurrence, and death) the survival-free of the outcome was estimated using the Kaplan-Meier method. Associations of patient and clinical characteristics with the outcomes were assessed by fitting Cox proportional hazards regression models.
  
  
  RESULTS
  Among the 240 patients diagnosed with MCC, 70 (29%) patients were identified who developed locoregional recurrence as the first site of recurrence. The median time from diagnosis to locoregional recurrence was 6 months. The pattern of first locoregional failure in this group includes 25 (10.4%) local, 18 (7.5%) in-transit, and 27 (11.3%) nodal recurrences. Recurrences were most commonly treated by surgery and radiation. At 3 years after the initial recurrence, locoregional recurrence-free survival was 75% and the distant recurrence-free survival was 56%. Locoregional recurrence is a poor prognostic sign associated with a 3-year overall survival of 39%. Nodal status at time of original surgery and time to first recurrence were important predictors of distant recurrence (P < 0.006) and overall survival following locoregional recurrence (P < 0.001).
  
  
  CONCLUSIONS
  Locoregional recurrence is a substantial problem in patients with MCC and is a poor prognostic sign. In those patients who experience a locoregional recurrence, aggressive efforts to regain locoregional control appear warranted and may result in long-term survival.
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Travis E
authors.initials: TE
authors.lastname: Grotz
authors.forename: Tina I
authors.initials: TI
authors.lastname: Tarantola
authors.forename: Clark C
authors.initials: CC
authors.lastname: Otley
authors.forename: Amy L
authors.initials: AL
authors.lastname: Weaver
authors.forename: Michaela E
authors.initials: ME
authors.lastname: McGree
authors.forename: James W
authors.initials: JW
authors.lastname: Jakub
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D015996:Survival Rate