title: Differential risk of non-Hodgkin's lymphoma in Italian patients with primary Sjögren's syndrome.
abstract: OBJECTIVE
  To assess the incidence of non-Hodgkin's lymphoma (NHL) and estimate the relative risk (RR) of developing lymphoproliferative complications in a large population of Italian patients with Sjögren's syndrome (SS) and to ascertain if any difference exists between the north and centre-south of Italy.
  
  
  METHODS
  Differential relative risks of NHL were obtained by comparing the number of observed cases with cases identified on the basis of age-sex-time specific incidence rates extracted from regional cancer registries.
  
  
  RESULTS
  Among the 331 patients with SS studied, 9 cases of NHL occurred, while no lymphoid malignancy appeared in patients with overlapping connective tissue disease (secondary SS) or in males with primary SS. As the number of NHL cases identified on the basis of the rate in the cancer registries would have been 0.27, the RR is 33.3 (p < 0.001). The incidence rate of NHL in Italian patients with SS is about 5.1/1000 person-years. 5.4/1000 per year in the north of the country and 4.8/1000 per year in the centre-south. The relative risks are, respectively, 34.7 and 32.5.
  
  
  CONCLUSIONS
  Italian patients with primary SS have increased risk of developing NHL. In this group, the absence of a significant difference between the north and the centre-south of Italy contrasts with the higher incidence of NHL in the general population of northern regions and strengthens the direct connection between primary SS and NHL.
authors.affiliation: Istituto di Clinica Medica I, Roma, Italy. gvalesini@mix.it
authors.forename: G
authors.initials: G
authors.lastname: Valesini
authors.forename: R
authors.initials: R
authors.lastname: Priori
authors.forename: D
authors.initials: D
authors.lastname: Bavoillot
authors.forename: J
authors.initials: J
authors.lastname: Osborn
authors.forename: M G
authors.initials: MG
authors.lastname: Danieli
authors.forename: N
authors.initials: N
authors.lastname: Del Papa
authors.forename: R
authors.initials: R
authors.lastname: Gerli
authors.forename: M
authors.initials: M
authors.lastname: Pietrogrande
authors.forename: M G
authors.initials: MG
authors.lastname: Sabbadini
authors.forename: F
authors.initials: F
authors.lastname: Silvestris
authors.forename: L
authors.initials: L
authors.lastname: Valsecchi
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D005260:Female; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008198:Lymph Nodes / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000150:complications* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012859:Sjogren's Syndrome / Q000150:complications* / Q000453:epidemiology* / Q000473:pathology; D013163:Splenomegaly / Q000453:epidemiology / Q000209:etiology
chemical_list: D001323:Autoantibodies