title: [Early detection of adenomas in asymptomatic subjects: flexible sigmoidoscopy or colonoscopy].
abstract: OBJECTIVE
  The aim of this study was to determine the frequency of adenomas as well as sensitivity, specificity, positive and negative predictive values of FS for polyp screening in two groups of asymptomatic individuals using colonoscopy (CP) as the gold standard.
  
  
  BACKGROUND
  Flexible sigmoidoscopy (FS) is the screening procedure of choice for polyps and colorectal carcinoma (CRC) in asymptomatic individuals. However, the validity of this approach has been questioned, specially in subjects with a family history of CRC.
  
  
  METHODS
  A total of 92 asymptomatic individuals were included in two groups: group A: with a family history (1st or 2nd degree relatives) of polyps or CRC (fifty-eight), and group B: without a family history and > 50 years (thirty-four). FS was simulated with the videocolonoscope until 60 cm, and was continued into the cecum. The number, type and localization of polyps were noted for each, FS and CP. The values mentioned previously were calculated according to established formulas. Comparisons were performed using Chi square test.
  
  
  RESULTS
  Adenomas were found in twenty individuals in group A (34.4%) and 7 in group B (20.5%), p = NS. Sensitivity for FS in group A was 42% vs 71% in group B, with a negative predictive value of 44.5 and 93%, respectively.
  
  
  CONCLUSIONS
  Colonoscopy is probably the screening procedure of choice in individuals with a family history of polyps or CRC. The utility of FS for screening purposes in asymptomatic individuals without a family history seems adequate, although more studies are required in different populations in our country.
authors.affiliation: Servicio de Gastroenterología y Unidad de Endoscopia Terapéutica, Hospital Gral. Dr. Manuel Gea González, México D.F.
authors.forename: A
authors.initials: A
authors.lastname: Farca Belsaguy
authors.forename: F
authors.initials: F
authors.lastname: Presenda Miller
authors.forename: G
authors.initials: G
authors.lastname: de la Mora Levy
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000367:Age Factors; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012737:Sex Factors; D012812:Sigmoidoscopy
vernacular_title: Detección temprana de adenomas en sujetos asintomáticos: sigmoidoscopia flexible o colonoscopia?