title: Lymphoma risk in psoriasis: results of the PUVA follow-up study.
abstract: OBJECTIVE
  To assess the risk of lymphoma in patients with psoriasis.
  
  
  METHODS
  Prospective cohort study that spans 30 years and a systematic review of the literature.
  
  
  METHODS
  Sixteen university medical centers.
  
  
  METHODS
  A total of 1380 patients with psoriasis who were initially treated with psoralen-UV-A (PUVA) from 1975 through 1976 and who underwent periodic interviews and physician examinations irrespective of their use of any treatment.
  
  
  METHODS
  Incidence of lymphoma relative to that expected in the general US population (original primary end point of the study).
  
  
  RESULTS
  The incidence of lymphoma in patients who received PUVA and were not exposed to high levels of methotrexate was comparable to that expected in the general population (incidence rate ratio, 0.85; 95% confidence interval, 0.37-1.67) but was elevated among those exposed to high levels of methotrexate (> or =36 months) (incidence rate ratio, 4.39; 95% confidence interval, 1.59-12.06).
  
  
  CONCLUSIONS
  Unless exposed to high levels of methotrexate, the risk of lymphoma among members of the PUVA Follow-up Study was comparable to that observed in the general population.
authors.affiliation: Department of Dermatology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA. rstern@bidmc.harvard.edu
authors.forename: Robert S
authors.initials: RS
authors.lastname: Stern
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D015994:Incidence; D008223:Lymphoma / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011701:PUVA Therapy / Q000009:adverse effects*; D011446:Prospective Studies; D011565:Psoriasis / Q000188:drug therapy*; D012307:Risk Factors; D011795:Surveys and Questionnaires