title: Sarcoidosis and cancer risk: systematic review and meta-analysis of observational studies.
abstract: BACKGROUND
  An increased cancer risk in patients with sarcoidosis has been suggested, although results are conflicting in a number of case-control and cohort studies. We conducted a systematic review of all available data and performed a meta-analysis to better define and quantify the association between sarcoidosis and cancer.
  
  
  METHODS
  We searched Medline and Embase for all original articles on cancer and sarcoidosis published up to January 2013. Two independent authors reviewed all titles/abstracts to identify studies according to predefined selection criteria. We derived summary estimates using a random-effects model and reported them as relative risk (RR). Publication bias was evaluated using a funnel plot and was quantified by the Egger test.
  
  
  RESULTS
  Sixteen original studies, involving > 25,000 patients, were included in the present review. The summary RR to develop all invasive cancers was 1.19 (95% CI, 1.07-1.32). The results for selected cancer sites indicated a significantly increased risk of skin (RR, 2.00; 95% CI, 1.69-2.36), hematopoietic (RR, 1.92; 95% CI, 1.41-2.62), upper digestive tract (RR, 1.73; 95% CI, 1.07-2.79), kidney (RR, 1.55; 95% CI, 1.21-1.99), liver (RR, 1.79; 95% CI, 1.03-3.11), and colorectal cancers (RR, 1.33; 95% CI, 1.07-1.67). There was no evidence of publication bias for all cancers (P = .9), nor for any specific cancer site.
  
  
  CONCLUSIONS
  The present meta-analysis suggests a significant, though moderate, association between sarcoidosis and malignancy.
authors.affiliation: Department of Epidemiology, Istituto di Ricerche Farmacologiche Mario Negri-Istituto di Ricovero e Cura a carattere Scientifico, Milan, Italy. Electronic address: martina.bonifazi@marionegri.it.
authors.forename: Martina
authors.initials: M
authors.lastname: Bonifazi
authors.affiliation: Department of Clinical Sciences and Community Health, Università Degli Studi di Milano, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bravi
authors.affiliation: Department of Biomedical Sciences and Public Health, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gasparini
authors.affiliation: Department of Clinical Sciences and Community Health, Università Degli Studi di Milano, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Gabrielli
authors.affiliation: Interstitial Lung Disease Unit, Royal Brompton Hospital, Royal Brompton & Harefield NHS Foundation Trust, London, England.
authors.forename: Athol U
authors.initials: AU
authors.lastname: Wells
authors.affiliation: Interstitial Lung Disease Unit, Royal Brompton Hospital, Royal Brompton & Harefield NHS Foundation Trust, London, England.
authors.forename: Elisabetta A
authors.initials: EA
authors.lastname: Renzoni
mesh_terms: D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D064887:Observational Studies as Topic; D012307:Risk Factors; D017565:Sarcoidosis, Pulmonary / Q000150:complications*