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Tobacco smoking and cancer: A meta‐analysis
Author(s) -
Gandini Sara,
Botteri Edoardo,
Iodice Simona,
Boniol Mathieu,
Lowenfels Albert B.,
Maisonneuve Patrick,
Boyle Peter
Publication year - 2007
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.23033
Subject(s) - medicine , relative risk , meta analysis , tobacco smoke , confounding , lung cancer , cancer , observational study , attributable risk , demography , environmental health , epidemiology , confidence interval , sociology
We conducted a systematic meta‐analysis of observational studies on cigarette smoking and cancer from 1961 to 2003. The aim was to quantify the risk for 13 cancer sites, recognized to be related to tobacco smoking by the International Agency for Research on Cancer (IARC), and to analyze the risk variation for each site in a systematic manner. We extracted data from 254 reports published between 1961 and 2003 (177 case‐control studies, 75 cohorts and 2 nested case‐control studies) included in the 2004 IARC Monograph on Tobacco Smoke and Involuntary Smoking . The analyses were carried out on 216 studies with reported estimates for ‘current’ and/or ‘former’ smokers. We performed sensitivity analysis, and looked for publication and other types of bias. Lung (RR = 8.96; 95% CI: 6.73–12.11), laryngeal (RR = 6.98; 95% CI: 3.14–15.52) and pharyngeal (RR = 6.76; 95% CI: 2.86–15.98) cancers presented the highest relative risks (RRs) for current smokers, followed by upper digestive tract (RR = 3.57; 95% CI: 2.63–4.84) and oral (RR = 3.43; 95% CI: 2.37–4.94) cancers. As expected, pooled RRs for respiratory cancers were greater than the pooled estimates for other sites. The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies. © 2007 Wiley‐Liss, Inc.