title: Prognostic significance of sentinel lymph node mapping in Merkel cell carcinoma: systematic review and meta-analysis of prognostic studies.
abstract: OBJECTIVE
  To assess through a systematic review and meta-analysis of the literature the prognostic implication of sentinel lymph node mapping in Merkel cell carcinoma (MCC).
  
  
  METHODS
  PubMed and SCOPUS databases were searched by using "Merkel AND sentinel" as keywords. All studies with prognostic information regarding SLN mapping in cN0 MCC patients were included. Hazard ratio (HR) for overall survival (OS) and disease free survival (DFS) was used as effect size.
  
  
  RESULTS
  SLN biopsy predicted better DFS and OS as compared to the nodal observation in cN0 MCC patients (pooled HR for DFS: 1.61 (95% CI: 1.05-2.46), P = 0.028; pooled HR for OS: 1.08 (95% CI: 0.55-2.10), P = 0.8). Pathologically negative SLN (SLN-) patients had better OS (pooled HR: 4.42 (95% CI: 1.82-10.7), P = 0.0009) and DFS (pooled HR: 2.58 (95% CI: 1.78-3.73)) as compared to SLN+ patients.
  
  
  CONCLUSIONS
  SLN mapping can provide strong prognostic information regarding OS and DFS in cN0 MCC patients. More importantly, SLN mapping can improve DFS and possibly OS in cN0 MCC patients as compared to nodal observation. As MCC is a rare tumor, large multicenter prospective studies are still needed to validate the survival benefit of SLN mapping.
authors: Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad 9176699199, Iran.
authors: Ramin
authors: R
authors: Sadeghi
authors: Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad 9176699199, Iran.
authors: Zohreh
authors: Z
authors: Adinehpoor
authors: Cutaneous Leishmaniasis Research Center, Mashhad University of Medical Sciences, Mashhad 9137913316, Iran.
authors: Masoud
authors: M
authors: Maleki
authors: Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran 1411713137, Iran.
authors: Babak
authors: B
authors: Fallahi
authors: Department of Nuclear Medicine and PET/CT Center, Oncology Institute of Southern Switzerland, Via Ospedale 12, 6500 Bellinzona, Switzerland.
authors: Luca
authors: L
authors: Giovanella
authors: Department of Nuclear Medicine and PET/CT Center, Oncology Institute of Southern Switzerland, Via Ospedale 12, 6500 Bellinzona, Switzerland.
authors: Giorgio
authors: 0000-0001-9808-780X
authors: G
authors: Treglia
mesh_terms: D000368:Aged; D015266:Carcinoma, Merkel Cell / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D012878:Skin Neoplasms / Q000473:pathology*