Location of Gliomas in Relation to Mobile Telephone Use: A Case-Case and Case-Specular Analysis

Abstract

The energy absorbed from the radio-frequency fields of mobile telephones depends strongly on distance from the source. The authors' objective in this study was to evaluate whether gliomas occur preferentially in the areas of the brain having the highest radio-frequency exposure. The authors used 2 approaches: In a case-case analysis, tumor locations were compared with varying exposure levels; in a case-specular analysis, a hypothetical reference location was assigned for each glioma, and the distances from the actual and specular locations to the handset were compared. The study included 888 gliomas from 7 European countries (2000-2004), with tumor midpoints defined on a 3-dimensional grid based on radiologic images. The case-case analyses were carried out using unconditional logistic regression, whereas in the case-specular analysis, conditional logistic regression was used. In the case-case analyses, tumors were located closest to the source of exposure among never-regular and contralateral users, but not statistically significantly. In the case-specular analysis, the mean distances between exposure source and location were similar for cases and speculars. These results do not suggest that gliomas in mobile phone users are preferentially located in the parts of the brain with the highest radio-frequency fields from mobile phones.

The Intracranial Distribution of Gliomas in Relation to Exposure From Mobile Phones: Analyses From the INTERPHONE Study

“…Our results concur with the observation of a statistically significant excess of gliomas on the self-reported side of mobile phone use (28). However, Larjavaara et al (28) did not observe significantly higher odds for a short distance between glioma and mobile phone for cases than for speculars (a hypothetical control location).…”

“…However, Larjavaara et al (28) did not observe significantly higher odds for a short distance between glioma and mobile phone for cases than for speculars (a hypothetical control location). Contrary to our method, they considered exposure on the same side of the head as the glioma, irrespective of the reported preferred side of mobile phone use.…”

“…These analyses included the 324 cases with preferred laterality out of the total 372 cases with TCSE. We fitted a model with shorter steps than in equation 2, a model with the mixing proportion specified as w pref = 0.85, and a model with a piecewise constant decreasing-distance relationship for the subsets used in previous case-only analyses: Denmark, Finland, Germany, Italy, Norway, Sweden, and the United Kingdom (n = 428 with preferred laterality out of 515 cases) in the study by Larjavaara et al (28) and Australia, Canada, France, Israel, and New Zealand (n = 332 with preferred laterality out of 380 cases) in the study by Cardis et al (30). Because of the uncertainty in the assessment of tumor origin, we conducted the analyses as in the paper by Grell et al (31), with the same data subset but using the center of gravity to see whether the choice of either point was crucial for these results.…”

“…Others investigated the risks of brain tumors in the different anatomical lobes of the brain separately (6,12,14,16,19,21). Some studies estimated the distance between the brain tumor and the mobile phone and divided cases into those in which the tumor was close to the phone, where most energy from RF-EMF is absorbed, and those in which the tumor was further away (27,28). Additionally, both the rate of energy absorption (the specific absorption rate (SAR)) inside the tumor (29) and the total cumulative specific energy (TCSE) absorbed for each tumor (30) have been estimated for use as exposure measures.…”

Electromagnetic interference and exposure from household wireless networks

“…Gliomas in areas of the brain with the highest estimated SAR were also significantly more common among users reporting long-term rather than short-term use in this study. In contrast, another analysis of tumor location in relation to phone handset use among cases from seven Interphone countries [15] did not find a statistically significant association between glioma tumor location and areas of the brain with the highest RF exposure, and the average distance of the tumors from the side of the head was not significantly shorter for a greater degree of phone use.…”