title: Increased cancer risks in myotonic dystrophy.
abstract: OBJECTIVE
  To estimate cancer risks for patients with myotonic dystrophy, given that increased risks for neoplasms in association with myotonic dystrophy type 1 and type 2 have been suggested in several studies but the risks of cancers have not been quantified.
  
  
  METHODS
  A cohort of 307 patients with myotonic dystrophy identified from medical records of Mayo Clinic in Rochester, MN, from January 1, l993, through May 28, 2010, was retrospectively analyzed. We estimated standardized incidence ratios (SIRs) of specific cancers for patients with myotonic dystrophy compared with age- and sex-specific cancer incidences of the general population. Age-dependent cumulative risks were calculated using the Kaplan-Meier method.
  
  
  RESULTS
  A total of 53 cancers were observed at a median age at diagnosis of 55 years. Patients with myotonic dystrophy had an increased risk of thyroid cancer (SIR, 5.54; 95% confidence interval [CI], 1.80-12.93; P=.001) and choroidal melanoma (SIR, 27.54; 95% CI, 3.34-99.49; P<.001). They may also have an increased risk of testicular cancer (SIR, 5.09; 95% CI, 0.62-18.38; P=.06) and prostate cancer (SIR, 2.21; 95% CI, 0.95-4.35; P=.05). The estimated cumulative risks at age 50 years were 1.72% (95% CI, 0.64%-4.55%) for thyroid cancer and 1.00% (95% CI, 0.25%-3.92%) for choroidal melanoma. There was no statistical evidence of an increased risk of brain, breast, colorectal, lung, renal, bladder, endometrial, or ovarian cancer; lymphoma; leukemia; or multiple myeloma.
  
  
  CONCLUSIONS
  Patients with myotonic dystrophy may have an increased risk of thyroid cancer and choroidal melanoma and, possibly, testicular and prostate cancers.
authors.affiliation: Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Aung Ko
authors.initials: AK
authors.lastname: Win
authors.forename: Promilla G
authors.initials: PG
authors.lastname: Perattur
authors.forename: Jose S
authors.initials: JS
authors.lastname: Pulido
authors.forename: Christine M
authors.initials: CM
authors.lastname: Pulido
authors.forename: Noralane M
authors.initials: NM
authors.lastname: Lindor
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000453:epidemiology; D015984:Causality; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology; D008223:Lymphoma / Q000453:epidemiology; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data*; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000175:diagnosis / Q000453:epidemiology*; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013736:Testicular Neoplasms / Q000453:epidemiology; D013964:Thyroid Neoplasms / Q000453:epidemiology; D014481:United States / Q000453:epidemiology