title: Reduced frequency of melanoma in 72,739 patients with psoriasis: A retrospective study.
abstract: BACKGROUND
  Chronic inflammatory conditions such as psoriasis may pose an increased risk of cancer due to impaired immunosurveillance resulting from the chronic inflammation and immunosuppressive medications. However, the relationship between psoriasis and the risk of melanoma is still controversial.
  
  
  OBJECTIVE
  To compare the occurrence of melanoma in a cohort of 72,739 psoriasis patients and in 25,956 non-dermatological patients.
  
  
  METHODS
  A record-linkage was performed between records of hospitalizations and access to day-hospital and day-surgery clinics and outpatient clinics. The frequency of melanoma was compared between psoriasis patients and vascular surgery patients. Occurrence of melanoma was compared by computing the relative risk (RR) and modelled using multiple logistic regression.
  
  
  RESULTS
  Overall, occurrence of melanoma was 1.8% (95% CI 1.5-2.2%) in psoriasis patients and 4.5% (95% CI 3.8-5.4%) in non-dermatological patients (RR = 0.40, 95% CI 0.31-0.51). The simultaneous adjustment for gender, age, and phototherapy yielded a RRadj = 0.54(95% CI 0.41-0.70. For patients who underwent phototherapy, vs. those who did not, the RRadj was 1.50 (95% CI 0.56-4.15).
  
  
  CONCLUSIONS
  In this large retrospective study, patients with psoriasis had a significantly lower probability of having melanoma when compared to a group of non-dermatological patients. Further studies, preferably with a concurrent longitudinal design to estimate incidence with more complete information, are needed to corroborate our findings.
authors.affiliation: Health Services Research Unit;
authors.forename: Andrea
authors.initials: A
authors.lastname: Paradisi
authors.affiliation: Health Services Research Unit;
authors.forename: Stefano
authors.initials: S
authors.lastname: Tabolli
authors.affiliation: First Dermatological Clinic.
authors.forename: Biagio
authors.initials: B
authors.lastname: Didona
authors.affiliation: Hospital Information System.
authors.forename: Luciano
authors.initials: L
authors.lastname: Sobrino
authors.affiliation: Medical Direction, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico (IDI-IRCCS), Via dei Monti di Creta, 104 I-00167 Rome, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Russo
authors.affiliation: Health Services Research Unit;
authors.forename: Damiano
authors.initials: D
authors.lastname: Abeni
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008545:Melanoma / Q000453:epidemiology*; D008875:Middle Aged; D010789:Phototherapy; D015995:Prevalence; D011565:Psoriasis / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000453:epidemiology*; D014652:Vascular Diseases / Q000453:epidemiology
keywords: epidemiology; melanoma; psoriasis; risk