RESUMEN
OBJECTIVE: To compare the incidence of subsequent cancers in a cohort of patients with primary Sjögren's syndrome (pSS) with that of the general population in the same region of England. METHODS: A retrospective analysis was carried out on 112 patients who had attended the out-patients department at University College Hospital, London, from 1979 onwards. Patients were followed up from diagnosis of pSS to diagnosis of first subsequent cancer, death, loss to follow-up or 31 December 2003 (the censoring date) to determine the person-years at risk for each individual. The expected numbers of subsequent cancers were calculated from sex-/age-/period-specific rates for the general population of southeast England, derived from registrations at the Thames Cancer Registry. Standardized incidence ratios (SIRs) were then calculated as the ratio of observed to expected numbers of cancers, along with 95% confidence intervals (CIs). Separate analyses were performed for all malignant cancers combined, lymphomas and non-lymphoid cancers. RESULTS: Among the 112 patients with pSS, 25 developed cancer (either before or after development of pSS), with lymphoma occurring in 11 cases. Nine patients had two cancers. There was a significantly elevated incidence of lymphomas in pSS patients compared with the general population (SIR 37.5, 95% CI 20.7-67.6). For non-lymphoid cancer, the observed increase in incidence was small and not statistically significant (SIR 1.5, 95% CI 0.9-2.6). CONCLUSION: This study confirms that there is an increased incidence of lymphoma in patients with pSS. An increase in the incidence of other cancers was not proven but the observation that some patients developed more than one cancer raises the possibility that there may be a subgroup of patients who are at greater risk of developing cancer.
Asunto(s)
Neoplasias/etiología , Síndrome de Sjögren/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Antirreumáticos/efectos adversos , Inglaterra/epidemiología , Métodos Epidemiológicos , Femenino , Humanos , Inmunosupresores/efectos adversos , Linfoma/epidemiología , Linfoma/etiología , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Síndrome de Sjögren/tratamiento farmacológico , Síndrome de Sjögren/epidemiologíaRESUMEN
BACKGROUND: To investigate whether patients with primary Sjögren's syndrome (pSS) have an increased tendency to develop other autoimmune diseases. METHODS: A retrospective case note review was carried out on 114 patients in whom a diagnosis of pSS had been made in a department of rheumatology from 1979 onwards. The year of diagnosis of pSS was recorded, plus the diagnosis and year of diagnosis of any other identified autoimmune disease. RESULTS: Of the 114 patients with pSS, seven (6%) were male and 107 (94%) female. Mean age at diagnosis of pSS was 53 years (range 21 to 83). Patients were followed up for an average of 10.5 years (range 0 to 23). Thirty eight patients (33.3%) were diagnosed as having another autoimmune disease, while nine (7.9%) had two or more. Thirteen additional autoimmune diseases were identified. Twenty five diagnoses (51.0%) were made before the diagnosis of pSS, three (6.1%) within the same year, and 21 (42.9%) after the diagnosis. Hypothyroidism was the most common autoimmune disease (n = 16). CONCLUSIONS: Although pSS is a relatively benign condition, affected individuals have an increased tendency to develop additional autoimmune diseases. Patients with pSS should be monitored on a regular basis for such diseases.