title: Extrathymic malignancies in a defined cohort of patients with myasthenia gravis.
abstract: BACKGROUND
  Myasthenia gravis (MG) may be associated with extrathymic malignancies, especially in patients with thymoma.
  
  
  OBJECTIVE
  To determine the frequency and type of extrathymic malignancies in MG patients from the Belgrade area, and to identify potential risk factors associated with tumors.
  
  
  METHODS
  The study comprised 390 patients with MG. Different sociodemographic and clinical variables potentially associated with extrathymic neoplasms were analyzed.
  
  
  RESULTS
  Extrathymic malignancies were present in 42 (10.8%) MG patients - 22 (52.4%) males and 20 (47.6%) females. The most frequently detected were breast (40%) and lung (40%) neoplasms. The tumors appeared with similar frequency before (45.2%) and after the onset of MG (42.9%). Significant predictors for the development of extrathymic malignancies were current age (p = 0.001) and immunoglobulin (IVIg) therapy (p = 0.021). On the other hand, current age (p=0.001), longer MG duration (p = 0.001) and generalized form of MG (p = 0.002) were significant predictors of malignancy occurring after the MG onset.
  
  
  CONCLUSIONS
  Our study revealed that older MG patients, as well as those with longer duration of the disease, and those who received IVIg therapy had a higher oncogenic risk for the development of extrathymic malignancies.
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: I
authors.initials: I
authors.lastname: Basta
authors.affiliation: Institute of Epidemiology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: T
authors.initials: T
authors.lastname: Pekmezovic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: S
authors.initials: S
authors.lastname: Peric
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: A
authors.initials: A
authors.lastname: Nikolic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: V
authors.initials: V
authors.lastname: Rakocevic-Stojanovic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Z
authors.initials: Z
authors.lastname: Stevic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: I
authors.initials: I
authors.lastname: Marjanovic
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia. Electronic address: dragana.lav@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Lavrnic
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007155:Immunologic Factors / Q000627:therapeutic use; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D012307:Risk Factors; D055771:Serbia / Q000453:epidemiology
chemical_list: D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors
keywords: Extrathymic malignancies; Myasthenia gravis; Risk factors; Therapy; Thymoma