Purpose: 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.
Conclusion: 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.
Amanda Gardner, HealthDay News, Oct 13, 2009
David Morgan, Reuters, Oct 13, 2009
Shari Roan, Los Angeles Times, October 14, 2009
Scientists looking at 23 studies involving almost 38,000 people initially see no connection. But a closer look at the highest-quality studies tells another story.
Evidence still fuzzy on cell phones, cancer
Elizabeth Landau, CNN, Nov 10, 2009
Video: Part 2 (5:29): http://www.youtube.com/watch?v=Cczwz1SE64c
Video: Part 3 (3:24): http://www.youtube.com/watch?v=BL1q1cEH-c
Media tele-conference on cellphones and brain tumors