title: Tuberculosis and risk of cancer: a Danish nationwide cohort study.
abstract: OBJECTIVE
  To investigate the short- and long-term risk of cancer in patients with active tuberculosis (TB).
  
  
  METHODS
  Using Danish nationwide databases, we quantified cancer risk in TB patients during 1978-2011 compared with the general population.
  
  
  RESULTS
  We observed 1747 cancers in 15 024 TB patients (median follow-up 8.5 years), reflecting a standardised incidence ratio (SIR) of 1.52 (95%CI 1.45-1.59). All-time SIR for extra-pulmonary cancer was 1.29 (95%CI 1.22-1.36) and for lung cancer it was 3.40 (95%CI 3.09-3.74). Absolute cancer risk 3 months after TB was 1.83% (SIR 11.09, 95%CI 9.82-12.48), with highly increased SIRs for malignant pleural mesothelioma (368.4), lung cancer (40.9), Hodgkin's lymphoma (30.6), ovarian cancer (26.4) and non-Hodgkin's malignant lymphoma (23.8). Between the 3-month and 5-year follow-up, the SIR for any cancer was 1.59 (95%CI 1.46-1.72), including 19- and 3-fold increases for malignant pleural mesothelioma and lung cancer. Beyond 5 years, the SIR of cancer was 1.17 (95%CI 1.10-1.25). Elevated long-term risks persisted for haematological (SIR 1.34, 95%CI 1.01-1.74) and tobacco-related cancers (SIR 1.78, 95%CI 1.60-1.97).
  
  
  CONCLUSIONS
  TB is a marker of occult lung cancer and several extra-pulmonary cancers. TB also predicts increased long-term risk of cancer, possibly related to chronic inflammation and shared risk factors, including immunosuppression and smoking.
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: D F
authors.initials: DF
authors.lastname: Simonsen
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: D K
authors.initials: DK
authors.lastname: Farkas
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Søgaard
authors.affiliation: Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Horsburgh
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: H T
authors.initials: HT
authors.lastname: Sørensen
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: R W
authors.initials: RW
authors.lastname: Thomsen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008654:Mesothelioma / Q000453:epidemiology / Q000209:etiology; D000086002:Mesothelioma, Malignant; D008875:Middle Aged; D012307:Risk Factors; D014376:Tuberculosis / Q000150:complications / Q000453:epidemiology*