title: Risk of subsequent basal cell carcinoma and squamous cell carcinoma of the skin among patients with prior skin cancer. Skin Cancer Prevention Study Group.
abstract: OBJECTIVE
  The primary aims of this study were to assess risk of subsequent basal and squamous cell skin cancer among patients with a prior history of these tumors and to examine these risks in relation to patient characteristics and life-style factors.
  
  
  METHODS
  Follow-up of participants in a randomized trial of betacarotene as a possible skin cancer preventive agent.
  
  
  METHODS
  Clinical centers in Los Angeles, Calif, San Francisco, Calif, Minneapolis, Minn, and Hanover, NH.
  
  
  METHODS
  Patients (n = 1805) who were diagnosed as having a basal or squamous cell skin cancer between January 1980 and February 1986 and were free of skin cancer at study entry.
  
  
  METHODS
  Time from study entry to first new occurrence of basal and squamous cell skin cancer.
  
  
  RESULTS
  The estimated risk of developing one or more new skin cancers was 35% at 3 years and 50% at 5 years. New skin cancers tended to be of the same cell type as the previous skin cancers. For both basal and squamous cell skin cancer, risk was higher among patients who were male, were over the age of 60 years, had more prior skin cancers, had severe actinic skin damage, or who burned easily with sun exposure. Compared with those who had never smoked, the rate of subsequent squamous cell skin cancer was higher among current smokers (rate ratio, 2.01; 95% confidence interval, 1.21 to 3.34) and former smokers (rate ratio, 1.62; 95% confidence interval, 1.07 to 2.47) and increased with both duration and amount smoked. There was no clear relationship between smoking and basal cell skin cancer; the rate appeared lower among heavy smokers but was unrelated to duration of smoking.
  
  
  CONCLUSIONS
  Persons with a prior nonmelanoma skin cancer had a substantial 5-year risk of developing another tumor of the same histologic type. Number of previous skin cancers, solar damage, and skin sensitivity to sun exposure were particularly related to this risk. The increased risk of squamous cell skin cancer associated with cigarette smoking merits further study.
authors.affiliation: Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH 03755-3861.
authors.forename: M R
authors.initials: MR
authors.lastname: Karagas
authors.forename: T A
authors.initials: TA
authors.lastname: Stukel
authors.forename: E R
authors.initials: ER
authors.lastname: Greenberg
authors.forename: J A
authors.initials: JA
authors.lastname: Baron
authors.forename: L A
authors.initials: LA
authors.lastname: Mott
authors.forename: R S
authors.initials: RS
authors.lastname: Stern
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000209:etiology* / Q000517:prevention & control; D002294:Carcinoma, Squamous Cell / Q000209:etiology* / Q000517:prevention & control; D002338:Carotenoids / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D011336:Probability; D012307:Risk Factors; D012737:Sex Factors; D012878:Skin Neoplasms / Q000209:etiology* / Q000517:prevention & control; D012907:Smoking / Q000009:adverse effects; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D002338:Carotenoids