Affiliations 

  • 1 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Network Aging Research, University of Heidelberg, Heidelberg, Germany; Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
  • 2 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany. Electronic address: v.walter@dkfz.de
  • 3 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Network Aging Research, University of Heidelberg, Heidelberg, Germany; Institute of Health Care and Social Sciences, FOM University, Essen, Germany
  • 4 International Agency for Research on Cancer (IARC), Lyon, France
  • 5 UKCRC Centre of Excellence for Public Health, Queens University of Belfast, Belfast, UK
  • 6 Department of Chronic Diseases, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands; Department of Gastroenterology and Hepatology, University Medical Centre, Utrecht, The Netherlands; Division of Epidemiology and Biostatistics, The School of Public Health, Imperial College London, London, UK; Department of Social & Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
  • 7 Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
  • 8 Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
  • 9 Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, USA
  • 10 Department of Public Health and Clinical Medicine, Cardiology, and Heart Center, Umeå University, Umeå, Sweden
  • 11 National Institute for Health and Welfare (THL), Helsinki, Finland
  • 12 Metabolic Epidemiology Branch, Division of Cancer Epidemiology & Genetics, National Cancer Institute, Rockville, USA
  • 13 Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway
  • 14 Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
  • 15 Nutritional Research, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden; Arcum, Arctic Research Centre at Umeå University, Umeå, Sweden
  • 16 Diet, Genes and Environment, Danish Cancer Society Research Center, Copenhagen, Denmark
  • 17 Public Health Directorate, Asturias, Spain
  • 18 Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
  • 19 Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, The Netherlands
  • 20 Hellenic Health Foundation, Athens, Greece; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA
  • 21 Hellenic Health Foundation, Athens, Greece; WHO Collaborating Center for Nutrition and Health, Unit of Nutritional Epidemiology and Nutrition in Public Health, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece
  • 22 Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany; Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany; German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
Ann Oncol, 2018 Feb 01;29(2):472-483.
PMID: 29244072 DOI: 10.1093/annonc/mdx761

Abstract

BACKGROUND: Smoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies and might also be associated with prognosis after CRC diagnosis. However, current evidence on smoking in association with CRC prognosis is limited.

PATIENTS AND METHODS: For this individual patient data meta-analysis, sociodemographic and smoking behavior information of 12 414 incident CRC patients (median age at diagnosis: 64.3 years), recruited within 14 prospective cohort studies among previously cancer-free adults, was collected at baseline and harmonized across studies. Vital status and causes of death were collected for a mean follow-up time of 5.1 years following cancer diagnosis. Associations of smoking behavior with overall and CRC-specific survival were evaluated using Cox regression and standard meta-analysis methodology.

RESULTS: A total of 5229 participants died, 3194 from CRC. Cox regression revealed significant associations between former [hazard ratio (HR) = 1.12; 95 % confidence interval (CI) = 1.04-1.20] and current smoking (HR = 1.29; 95% CI = 1.04-1.60) and poorer overall survival compared with never smoking. Compared with current smoking, smoking cessation was associated with improved overall (HR<10 years = 0.78; 95% CI = 0.69-0.88; HR≥10 years = 0.78; 95% CI = 0.63-0.97) and CRC-specific survival (HR≥10 years = 0.76; 95% CI = 0.67-0.85).

CONCLUSION: In this large meta-analysis including primary data of incident CRC patients from 14 prospective cohort studies on the association between smoking and CRC prognosis, former and current smoking were associated with poorer CRC prognosis compared with never smoking. Smoking cessation was associated with improved survival when compared with current smokers. Future studies should further quantify the benefits of nonsmoking, both for cancer prevention and for improving survival among CRC patients, in particular also in terms of treatment response.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.