@article{3178659,
    title = "Impact of prediagnostic smoking and smoking cessation on colorectal
cancer prognosis: a meta-analysis of individual patient data from
cohorts within the CHANCES consortium",
    author = "Ordonez-Mena, J. M. and Walter, V. and Schoettker, B. and Jenab, M. and and O'Doherty, M. G. and Kee, F. and Bueno-de-Mesquita, B. and Peeters, P. and H. M. and Stricker, B. H. and Ruiter, R. and Hofman, A. and Soderberg, and S. and Jousilahti, P. and Kuulasmaa, K. and Freedman, N. D. and and Wilsgaard, T. and Wolk, A. and Nilsson, L. M. and Tjonneland, A. and and Quiros, J. R. and van Duijnhoven, F. J. B. and Siersema, P. D. and and Boffetta, P. and Trichopoulou, A. and Brenner, H. and Consortium Hlth and Ageing Network",
    journal = "Annals of Oncology",
    year = "2018",
    volume = "29",
    number = "2",
    pages = "472-483",
    publisher = "Oxford University Press",
    issn = "0923-7534, 1569-8041",
    doi = "10.1093/annonc/mdx761",
    keywords = "smoking; smoking cessation; colorectal neoplasms; survival;
meta-analysis",
    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<10years =
0.78; 95% CI = 0.69-0.88; HR >= 10years = 0.78; 95% CI = 0.63-0.97)
and CRC-specific survival (HR similar to 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."
}