title: No increase in cancer incidence detected after cyclophosphamide in a French cohort of patients with progressive multiple sclerosis.
abstract: BACKGROUND
  Cyclophosphamide is still used in progressive forms of multiple sclerosis (MS) in view of its suggested efficacy and safety in the short term. No data exist on its long-term safety in MS, particularly on the risk of malignancy.
  
  
  OBJECTIVE
  The objective of this study was to evaluate cancer incidence in MS after cyclophosphamide treatment.
  
  
  METHODS
  We performed a historical prospective study in a cohort of MS patients treated with cyclophosphamide. We collected demographic data and medical history from medical databases and patient interviews. Reported cancers were histologically confirmed. Cancer incidence was compared with the incidence in the general population by estimating standardized incidence ratios (SIRs).
  
  
  RESULTS
  We included 354 patients, with a median follow-up of 5 years (range 2-15) after cyclophosphamide treatment. Fifteen patients developed a solid cancer, which occurred at a median of 3 years (range 0.5-14) after cyclophosphamide introduction. The cumulative incidence of cancer after cyclophosphamide was 3.1% at 5 years and 5.9% at 8 years. We found no increase in cancer incidence after cyclophosphamide treatment in men (SIR = 0.83, 95% confidence interval [CI] 0.30-1.82), women (SIR = 0.99, 95% CI 0.43-1.95), or men and women combined (SIR = 0.92, 95% CI 0.50-1.54).
  
  
  CONCLUSIONS
  We found no evidence of an increased risk of cancer associated with cyclophosphamide treatment in MS patients.
authors.affiliation: Department of Neurology, Université Lille Nord de France, Lille, France.
authors.forename: R
authors.initials: R
authors.lastname: Le Bouc
authors.forename: H
authors.initials: H
authors.lastname: Zéphir
authors.forename: B
authors.initials: B
authors.lastname: Majed
authors.forename: A
authors.initials: A
authors.lastname: Vérier
authors.forename: M
authors.initials: M
authors.lastname: Marcel
authors.forename: P
authors.initials: P
authors.lastname: Vermersch
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003520:Cyclophosphamide / Q000009:adverse effects*; D005260:Female; D005602:France; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy*; D009369:Neoplasms / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents; D003520:Cyclophosphamide