title: Molecular alterations in spontaneous sputum of cancer-free heavy smokers: results from a large screening program.
abstract: OBJECTIVE
  The high mortality rate for lung cancer is likely to be reduced by the development of a panel of sensitive biological markers able to identify early-stage lung cancers or subjects at high risk. The aim of this study was to establish the frequency of K-ras and p53 mutations and p16(INK4A), RASSF1A, and NORE1A hypermethylation in sputum of a large cohort of cancer-free heavy smokers and to assess whether these markers are suitable for a routine use in the clinical practice for the early diagnosis of pulmonary cancer.
  
  
  METHODS
  Sputum samples were collected from 820 heavy smokers. Inclusion criteria consisted of radiologic and cytologic absence of pulmonary lesions, age at least 60 years, male gender, and a smoking history of at least 20 pack-years.
  
  
  RESULTS
  The analysis identified 56 individuals (6.9%) with one molecular alteration. p53 mutation and p16(INK4A), RASSF1A, and NORE1A methylation frequencies were 1.9%, 5.1%, 0.8%, and 1.0%, respectively; no K-ras mutations were found. One patient with p53 mutations was diagnosed with an early-stage lung cancer after 3-years of follow-up. The molecular analysis of bronchoscopy samples confirmed in half of the cases alterations present in sputum without revealing additional molecular changes.
  
  
  CONCLUSIONS
  Genetic and epigenetic abnormalities can be detected in cancer-free heavy smokers. Although the predictive value of the cancer risk is still to be established as it requires not less than 5 years of follow-up, p53 and p16(INK4A) are more promising candidates than K-ras, RASSF1A, and NORE1A for the pulmonary molecular screening of heavy smokers healthy individuals.
authors.affiliation: Molecular Genetics Laboratory, IRCCS Istituto Clinico Humanitas, Milan, Italy.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Baryshnikova
authors.forename: Annarita
authors.initials: A
authors.lastname: Destro
authors.forename: Maurizio Valentino
authors.initials: MV
authors.lastname: Infante
authors.forename: Silvio
authors.initials: S
authors.lastname: Cavuto
authors.forename: Umberto
authors.initials: U
authors.lastname: Cariboni
authors.forename: Marco
authors.initials: M
authors.lastname: Alloisio
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Ceresoli
authors.forename: Romano
authors.initials: R
authors.lastname: Lutman
authors.forename: Giorgio
authors.initials: G
authors.lastname: Brambilla
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Chiesa
authors.forename: Gianni
authors.initials: G
authors.lastname: Ravasi
authors.forename: Massimo
authors.initials: M
authors.lastname: Roncalli
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D001999:Bronchoscopy; D015331:Cohort Studies; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D042241:Early Diagnosis; D005500:Follow-Up Studies; D019942:Genes, p16; D016158:Genes, p53; D011905:Genes, ras; D005820:Genetic Testing; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics; D011230:Precancerous Conditions / Q000235:genetics* / Q000378:metabolism; D012907:Smoking / Q000235:genetics*; D013183:Sputum / Q000166:cytology / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C411762:RASSF1 protein, human; C454042:RASSF5 protein, human; D025521:Tumor Suppressor Proteins; D020559:Monomeric GTP-Binding Proteins