Mobile Phones and Cancer

Next Steps

To the Editors:

We welcome the commentary by Samet et al¹ and their recommendation for reanalysis of the main case-control studies on radiofrequency electromagnetic fields (the basis of all wireless technology). This reanalysis is something we have also suggested. The authors discuss pros and cons for the IARC classification of radiofrequency electromagnetic fields as “possibly carcinogenic to humans” (group 2B). However, several more recently published articles are either misinterpreted in or omitted from their presentation—for instance, 3 articles published by our research group on meningioma,² acoustic neuroma,³ and malignant brain tumors.⁴ Our study and the INTERPHONE study differ in their recruitment of cases and controls, participation rates, and assessment of exposure, but restricting to the same age groups and omitting the use of cordless phones (as in INTERPHONE) gives similar results.⁵

The Danish cohort study⁶ was included in the IARC evaluation of radiofrequency electromagnetic fields, with the conclusion that “phone provider, as a surrogate for mobile phone use, could have resulted in considerable misclassification in exposure assessment.” Samet et al^l write that this was “a study considered by the IARC Working Group” but fail to report the conclusion by the Working Group. Samet et al^l do not mention the analytic studies we published in 2013, but they do reference an update of the Danish cohort study and Benson et al⁷—the latter also published in 2013.

We have discussed elsewhere the increasing incidence of brain tumors in several countries including Denmark. There was a sharp increase in the incidence of brain tumors during 2003–2012 (41% in men and 46% in women). This casts doubt on the findings of both Deltour et al⁸ on glioma incidence in the Nordic countries during 1997–2008 and the recent report on the Danish cohort study on mobile phone users.⁶

In summary, we disagree with the way Samet et al¹ have chosen to present evidence regarding mobile phones and cancer. We do, however, agree with the authors’ advice on “keeping people well-informed.” In considering the most up-to-date publications, we find increasing evidence of an association between the use of mobile or cordless phones and glioma and acoustic neuroma.

Lennart Hardell

Michael Carlberg

Department of Oncology

University Hospital

Örebro, Sweden

[email protected]

Fredrik Söderqvist

Centre for Clinical Research

Uppsala University

Central Hospital of Västerås

Västerås, Sweden

Kjell Hansson Mild

Department of Radiation Physics

Umeå University

Umeå, Sweden