Mobile phone use and risk of tumors: a meta-analysis.
OBJECTIVE
Case-control studies have reported inconsistent findings regarding the association between mobile phone use and tumor risk. We investigated these associations using a meta-analysis.


METHODS
We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library in August 2008. Two evaluators independently reviewed and selected articles based on predetermined selection criteria.


RESULTS
Of 465 articles meeting our initial criteria, 23 case-control studies, which involved 37,916 participants (12,344 patient cases and 25,572 controls), were included in the final analyses. Compared with never or rarely having used a mobile phone, the odds ratio for overall use was 0.98 for malignant and benign tumors (95% CI, 0.89 to 1.07) in a random-effects meta-analysis of all 23 studies. However, a significant positive association (harmful effect) was observed in a random-effects meta-analysis of eight studies using blinding, whereas a significant negative association (protective effect) was observed in a fixed-effects meta-analysis of 15 studies not using blinding. Mobile phone use of 10 years or longer was associated with a risk of tumors in 13 studies reporting this association (odds ratio = 1.18; 95% CI, 1.04 to 1.34). Further, these findings were also observed in the subgroup analyses by methodologic quality of study. Blinding and methodologic quality of study were strongly associated with the research group.


CONCLUSIONS
The current study found that there is possible evidence linking mobile phone use to an increased risk of tumors from a meta-analysis of low-biased case-control studies. Prospective cohort studies providing a higher level of evidence are needed.
Myung
Seung-Kwon
SK
Smoking Cessation Clinic, Center for Cancer Prevention and Detection, Division of Cancer Prevention, National Cancer Control Research Institute, National Cancer Center, Goyang, Republic of Korea; msk@ncc.re.kr.
Ju
Woong
W
McDonnell
Diana D
DD
Lee
Yeon Ji
YJ
Kazinets
Gene
G
Cheng
Chih-Tao
CT
Moskowitz
Joel M
JM
D001932:Brain Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D016022:Case-Control Studies; D040421:Cell Phone / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007723:Korea; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013997:Time Factors