title: Subsequent squamous- and basal-cell carcinomas in kidney-transplant recipients after the first skin cancer: cumulative incidence and risk factors.
abstract: BACKGROUND
  The risk of skin cancer is highly increased in kidney-transplant recipients (KTR), but the risk of subsequent skin cancers is less well studied. The aim of this study was to estimate the cumulative incidence of subsequent squamous- and basal-cell carcinomas (BCCs) and to analyze potential risk factors.
  
  
  METHODS
  All histologically confirmed skin cancers between 1966 and 2006 were included in the study and counted. Cumulative incidences of subsequent squamous- and BCCs were calculated using Kaplan-Meier survival analyses. For the analyses of risk factors, we used Cox proportional hazard analyses.
  
  
  RESULTS
  A total of 239 (13%) of 1906 KTR developed skin cancer of whom 222 were diagnosed in our hospital. Altogether 167 (75%) of these 222 patients developed multiple skin cancers. The cumulative incidence of a second skin cancer increased from 32%, 1 year, to 59%, 3 years, and 72%, 5 years after the first skin cancer. KTR who started with squamous-cell carcinoma (SCC) mainly developed SCC and recipients who started with BCC mainly developed BCC as second skin cancer. Immunosuppression with azathioprine in combination with prednisone was associated with a significantly increased risk of subsequent SCCs but not with subsequent BCCs.
  
  
  CONCLUSIONS
  Skin cancer multiplicity is common in KTR. Patients with a first skin cancer are at increased risk for more skin cancers and need to be carefully checked for subsequent skin cancers.
authors.affiliation: Department of Dermatology, Leiden University Medical Centre, Leiden, The Netherlands. h.c.wisgerhof@lumc.nl
authors.forename: Hermina C
authors.initials: HC
authors.lastname: Wisgerhof
authors.forename: Jeroen R J
authors.initials: JR
authors.lastname: Edelbroek
authors.forename: Johan W
authors.initials: JW
authors.lastname: de Fijter
authors.forename: Geert W
authors.initials: GW
authors.lastname: Haasnoot
authors.forename: Frans H J
authors.initials: FH
authors.lastname: Claas
authors.forename: Rein
authors.initials: R
authors.lastname: Willemze
authors.forename: Jan N Bouwes
authors.initials: JN
authors.lastname: Bavinck
mesh_terms: D001379:Azathioprine / Q000009:adverse effects / Q000627:therapeutic use; D002280:Basal Cell Carcinoma / Q000453:epidemiology*; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use; D015994:Incidence; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000276:immunology / Q000401:mortality; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D011241:Prednisone / Q000009:adverse effects / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology*; D013472:Sunlight / Q000009:adverse effects; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D001379:Azathioprine; D011241:Prednisone