title: Merkel cell carcinoma: what makes a difference?
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is a cutaneous neuroendocrine tumor that may spread via lymphatics and can therefore be staged with sentinel lymph node biopsy (SLNB). MCC is radiosensitive and chemosensitive, although the role of adjuvant therapy is still unclear. We examined the impact of different treatments on the outcome of MCC.
  
  
  METHODS
  We performed a retrospective review of state cancer registry data from California, Oregon, and Washington of patients diagnosed with primary skin MCC between 1988 and 2012 (n = 4,038). Data were analyzed using Cox regression and Kaplan-Meier methods to examine disease-specific survival.
  
  
  RESULTS
  Patients with positive nodes or no documented nodal evaluation had worse survival compared with node-negative patients. No nodal evaluation had decreased survival compared with lymph node evaluation by SLNB. Completion lymph node dissection conferred improved survival in patients with a positive SLNB. In clinically node-negative patients who had a positive SLNB, radiation and chemotherapy did not affect survival.
  
  
  CONCLUSIONS
  Lymph node evaluation is an important component to MCC treatment. The role of adjuvant radiation and chemotherapy needs further evaluation.
authors.affiliation: Department of Surgery, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Tseng
authors.affiliation: Department of Surgery, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Birat
authors.initials: B
authors.lastname: Dhungel
authors.affiliation: Division of Surgical Oncology, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Jane K
authors.initials: JK
authors.lastname: Mills
authors.affiliation: Department of Surgery, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Brian S
authors.initials: BS
authors.lastname: Diggs
authors.affiliation: Division of Surgical Oncology, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Roshanthi
authors.initials: R
authors.lastname: Weerasinghe
authors.affiliation: Division of Surgical Oncology, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Jeanine
authors.initials: J
authors.lastname: Fortino
authors.affiliation: Department of Surgery, Oregon Health & Science University, Portland, OR, USA; Division of Surgical Oncology, Oregon Health & Science University, Portland, OR, USA. Electronic address: vettoj@ohsu.edu.
authors.forename: John T
authors.initials: JT
authors.lastname: Vetto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D015266:Carcinoma, Merkel Cell / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009922:Oregon / Q000453:epidemiology; D012042:Registries; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate; D014861:Washington / Q000453:epidemiology
keywords: Chemotherapy; Lymph node; Merkel cell carcinoma; Radiation