title: Conditional survival after surgical treatment of melanoma: an analysis of the Surveillance, Epidemiology, and End Results database.
abstract: BACKGROUND
  Survival curves following surgical treatment of cutaneous melanoma are heavily influenced by early deaths. Therefore, survival estimates may be misleading for long-term cancer survivors. We examined whether conditional survival (CS) is more accurate in predicting long-term melanoma survival.
  
  
  METHODS
  We used the Surveillance, Epidemiology, and End Results database (1992-2005) to identify patients who underwent surgical treatment for melanoma. We included patients with T2-T4 disease and with known nodal status. Patients were stratified into low-risk (T2-3N0M0) and high-risk (T4N0M0 or T2-4N1-3M0) categories. We defined CS as time-specific estimates conditioned on living to a certain point in follow-up, and calculated 10-year cancer-specific survival curves conditioned on annual survival. We adjusted for potential confounders using a Cox proportional hazards regression model (alpha = 0.05).
  
  
  RESULTS
  A total of 8647 patients met inclusion criteria (low-risk, 5987 [69.2%]; high-risk, 2660 [30.8%]). At diagnosis, low-risk patients had a significantly better 10-year survival rate (low-risk, 79.6%; high-risk, 41.2%; P < 0.001). On CS analysis, survival differences remained until 8 years after treatment, after which 10-year cancer-specific survival rates were no longer significantly different (P = 0.51) for low-risk (95.4%) and high-risk (91.7%) groups. Multivariate analysis demonstrated that age, gender, location, and ulceration (initial predictors of survival) were no longer predictive after 8 years of survival.
  
  
  CONCLUSIONS
  For patients who survive 8 years after surgical treatment of melanoma, CS data become discordant with traditionally used estimates. Our findings have important implications for patient counseling, as high-risk melanoma survivors may require no more intensive surveillance than low-risk survivors 8 years after treatment.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Natasha M
authors.initials: NM
authors.lastname: Rueth
authors.forename: Shawn S
authors.initials: SS
authors.lastname: Groth
authors.forename: Todd M
authors.initials: TM
authors.lastname: Tuttle
authors.forename: Beth A
authors.initials: BA
authors.lastname: Virnig
authors.forename: Waddah B
authors.initials: WB
authors.lastname: Al-Refaie
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Habermann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015999:Multivariate Analysis; D011159:Population Surveillance; D016016:Proportional Hazards Models; D018426:SEER Program; D012878:Skin Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D015996:Survival Rate; D014481:United States / Q000453:epidemiology