title: Stopping Smoking Reduces Mortality in Low-Dose Computed Tomography Screening Participants.
abstract: The National Lung Screening Trial has achieved a 7% reduction in total mortality with low-dose computed tomography (LDCT) screening as compared with in the chest radiography arm. Other randomized trials are under way, comparing LDCT screening with no intervention. None of these studies was designed to investigate the impact of smoking habits on screening outcome. In the present study, we tested the effect of stopping smoking on the overall mortality of participants undergoing repeated LDCT screening for many years.
  
  
  
  Between 2000 and 2010, 3381 smokers aged 50 years or older were enrolled in two LDCT screening programs. On the basis of the last follow-up information, subjects were divided into two groups: current smokers throughout the screening period and former smokers.
  
  
  
  With a median follow-up time of 9.7 years and a total of 32,857 person-years (PYs) of follow-up, a total of 151 deaths were observed in the group of 1797 current smokers (17,846 PYs) versus 109 among 1584 former smokers (15,011 PYs), corresponding to mortality rates of 8.46 and 7.26 for every 1000 PYs, respectively. Compared with current smokers, former smokers had an adjusted mortality hazard ratio of 0.61 (95% confidence interval: 0.44-0.83), with a 39% reduction in mortality. A similar reduction in mortality was observed in the subset of 712 late quitters, with a hazard ratio of 0.65 (95% confidence interval: 0.44-0.96).
  
  
  
  Stopping smoking significantly reduces the overall mortality of smokers enrolled in LDCT screening programs. The beneficial effect of stopping smoking on total mortality appears to be threefold to fivefold greater than the one achieved by earlier detection in the National Lung Screening Trial.
authors.affiliation: Thoracic Surgery Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy. Electronic address: ugo.pastorino@istitutotumori.mi.it.
authors.forename: Ugo
authors.initials: U
authors.lastname: Pastorino
authors.affiliation: Tobacco Control Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Boffi
authors.affiliation: Radiology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Marchianò
authors.affiliation: Thoracic Surgery Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Sestini
authors.affiliation: Tobacco Control Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Munarini
authors.affiliation: Radiology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Calareso
authors.affiliation: Tumor Genomics Unit, Department of Experimental Oncology, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Boeri
authors.affiliation: Department of Pathology and Laboratory Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy; Department of Oncology and Hemato-Oncology, Università degli Studi, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pelosi
authors.affiliation: Tumor Genomics Unit, Department of Experimental Oncology, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Sozzi
authors.affiliation: Department of Clinical Sciences, Section of Radiology, University of Parma, Parma, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Silva
authors.affiliation: Department of Clinical Sciences, Section of Radiology, University of Parma, Parma, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Galeone
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Division of Biostatistics, Epidemiology and Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Ghirardi
authors.affiliation: Division of Biostatistics, Epidemiology and Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Corrao
mesh_terms: D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D013902:Radiography, Thoracic; D012907:Smoking / Q000009:adverse effects*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: LDCT; Lung cancer; Mortality; Screening; Smoking