title: Risk of second primary in situ and invasive melanoma in a Dutch population-based cohort: 1989-2008.
abstract: BACKGROUND
  Patients with melanoma are at increased risk of developing a subsequent melanoma.
  
  
  OBJECTIVE
  To estimate the risks of developing a second primary in situ or invasive cutaneous melanoma after a first melanoma, between 1989 and 2008.
  
  
  METHODS
  Patients were followed until diagnosis of a second melanoma, date of death or end of study. Cumulative risks, standardized incidence ratio (SIR, observed second melanomas divided by background age-, calendar- and sex-specific incidence rates of melanoma, as recorded in the Netherlands Cancer Registry) and absolute excess risk (AER, observed minus expected per 10 000 person-years) of second melanomas were calculated.
  
  
  RESULTS
  In total, 10 765 patients with in situ melanoma and 46 700 with invasive melanoma were included. The cumulative risks of a second invasive melanoma after a first in situ or invasive melanoma at 20 years of follow-up were 6·2% and 5·0%, respectively. The relative risk of developing any melanoma (in situ or invasive) after any first melanoma (measured as SIR) varied from 12·4-fold [invasive after invasive melanoma; 95% confidence interval (CI) = 11·6-13·2] to 26·4-fold (in situ after in situ melanoma; 95% CI = 22·6-30·7) increase compared with the general population. SIRs and AERs remained elevated up to 20 years after the first melanoma.
  
  
  CONCLUSIONS
  This study shows significantly increased long-term risks (both relative and absolute) of developing a second invasive melanoma after a first melanoma (invasive and in situ), and might serve as a basis for follow-up guidelines.
authors: Departments of Dermatology Public Health, Erasmus MC University Medical Center, Rotterdam, The Netherlands. r.vanderleest@erasmusmc.nl
authors: R J T
authors: RJ
authors: van der Leest
authors: L
authors: L
authors: Liu
authors: J W W
authors: JW
authors: Coebergh
authors: H A M
authors: HA
authors: Neumann
authors: W J
authors: WJ
authors: Mooi
authors: T
authors: T
authors: Nijsten
authors: E
authors: E
authors: de Vries
mesh_terms: D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D009426:Netherlands / Q000453:epidemiology; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality