title: Serum concentration of alpha-1 antitrypsin is significantly higher in colorectal cancer patients than in healthy controls.
abstract: BACKGROUND
  The association between alpha-1 antitrypsin (AAT) deficiency and colorectal cancer (CRC) is currently controversial. The present study compares AAT serum concentrations and gene frequencies between a group of CRC patients and a control group of healthy unrelated people (HUP).
  
  
  METHODS
  267 CRC subjects (63% males, 72 ± 10 years old) were enlisted from a Hospital Clinic setting in Asturias, Spain. The HUP group comprised 327 subjects (67% males, mean age 70 ± 7.5 years old) from the same geographical region. Outcome measures were AAT serum concentrations measured by nephelometry, and AAT phenotyping characterization by isoelectric focusing.
  
  
  RESULTS
  Significantly higher serum concentrations were found among CRC (208 ± 60) than in HUP individuals (144 ± 20.5) (p = 0.0001). No differences were found in the phenotypic distribution of the Pi*S and Pi*Z allelic frequencies (p = 0.639), although the frequency of Pi*Z was higher in CRC (21%) than in HUP subjects (15%).
  
  
  CONCLUSIONS
  The only statistically significant finding in this study was the markedly higher AAT serum concentrations found in CRC subjects compared with HUP controls, irrespective of whether their Pi* phenotype was normal (Pi*MM) or deficient (Pi*MS, Pi*MZ and Pi*SZ). Although there was a trend towards the more deficient Pi* phenotype the more advanced the tumor, the results were inconclusive due to the small sample size. Consequently, more powerful studies are needed to reach firmer conclusions on this matter.
authors.affiliation: General Surgery Department, Hospital Valle del Nalón, 33920 Langreo, Principality of Asturias, Spain. perezholandas@gmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: Pérez-Holanda
authors.forename: Ignacio
authors.initials: I
authors.lastname: Blanco
authors.forename: Manuel
authors.initials: M
authors.lastname: Menéndez
authors.forename: Luis
authors.initials: L
authors.lastname: Rodrigo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000097:blood* / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D015854:Up-Regulation; D000515:alpha 1-Antitrypsin / Q000097:blood* / Q000235:genetics; D019896:alpha 1-Antitrypsin Deficiency / Q000097:blood* / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; C043392:SERPINA1 protein, human; D000515:alpha 1-Antitrypsin