title: Adjuvant Radiation Therapy and Chemotherapy in Merkel Cell Carcinoma: Survival Analyses of 6908 Cases From the National Cancer Data Base.
abstract: Merkel cell carcinoma (MCC) has a high risk of recurrence after initial surgical therapy. Adjuvant radiation therapy (RT) and chemotherapy may be used to reduce the risk of locoregional and systemic recurrence, respectively, but there are conflicting data regarding their impact on survival. We performed a retrospective analysis of MCC cases from the National Cancer Data Base (NCDB) to assess whether adjuvant therapy was associated with differences in survival.
  
  
  
  Six thousand nine hundred and eight MCC patients with staging, treatment, and survival data were included. Multivariable analyses were conducted for overall survival (OS) with various treatment modalities while adjusting for prognostic variables including age, sex, comorbidities (Charlson/Deyo score), margin status, primary tumor site and size, and lymph node status. All statistical tests were two-sided.
  
  
  
  For localized MCC (stage I: n = 3369, stage II: n = 1474 ), surgery plus adjuvant RT was associated with statistically significantly better OS than with surgery alone in multivariable analyses (stage I: hazard ratio [HR] = 0.71, 95% confidence interval [CI] = 0.64 to 0.80, P < .001; stage II: HR = 0.77, 95% CI = 0.66 to 0.89, P < .001). In patients with regional nodal metastases (stage III: n = 2065 ), neither adjuvant RT nor chemotherapy was associated with statistically significantly improved or worsened OS.
  
  
  
  In this study of the largest MCC cohort reported to date, adjuvant RT was associated with improved OS in stages I-II MCC. Neither adjuvant RT nor chemotherapy was associated with improved OS in stage III MCC. These results, with the limitations of retrospective analyses, are consistent with earlier studies suggesting benefit with adjuvant RT but do not support the routine use of adjuvant chemotherapy in MCC.
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG) sbhatia@uw.edu pnghiem@uw.edu.
authors.forename: Shailender
authors.initials: S
authors.lastname: Bhatia
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Barry E
authors.initials: BE
authors.lastname: Storer
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Jayasri G
authors.initials: JG
authors.lastname: Iyer
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Ata
authors.initials: A
authors.lastname: Moshiri
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Upendra
authors.initials: U
authors.lastname: Parvathaneni
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: David
authors.initials: D
authors.lastname: Byrd
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Sober
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Vernon K
authors.initials: VK
authors.lastname: Sondak
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG).
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Gershenwald
authors.affiliation: University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA (SB, BES, JGI, AM, UP, DB, PN); Massachusetts General Hospital, Boston, MA (AJS); H. Lee Moffitt Cancer Center, Tampa, FL (VKS); The University of Texas MD Anderson Cancer Center, Houston, TX (JEG) sbhatia@uw.edu pnghiem@uw.edu.
authors.forename: Paul
authors.initials: P
authors.lastname: Nghiem
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015266:Carcinoma, Merkel Cell / Q000401:mortality / Q000556:secondary* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D016208:Databases, Factual / Q000706:statistics & numerical data; D062109:Dermatologic Surgical Procedures; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents