The question of whether radiofrequency electromagnetic fields may initiate or promote cancer has been investigated in many occupational, personal and residential areas (e.g., exposure to TV broadcasting, radar, or mobile communications). Research activities have, in recent years, focused more and more on mobile communications, this is because of the exponential increase of mobile phone use in the past 20 years. Mobile phones are positioned close to the ear during a call and thereby the head is most strongly exposed. For this reason, the research focus was especially on brain tumors and tumors of adjacent tissues.

Brain tumors are benign and malignant tumors of the brain. They are classified according to the histological cell types into e.g. gliomas, meningiomas and acoustic neuromas. Gliomas arise from the supportive tissues of the brain (glial cells) and are the most common type of brain tumors. Meningiomas are benign tumors of the meninges (layers of tissue covering the brain). Acoustic neuromas are benign, slowly growing tumors of the Schwann cells of the acoustic nerve.

A particular problem with brain tumors arises from their location. Due to the surrounding cranium, the space for the brain is limited, therefore a growing tumor steadily increases the pressure in the brain. For this reason, even benign brain tumors are also threatening, because they can evoke severe symptoms and functional disorders of the central nervous system solely by extrusion of the tissue. Brain tumors are a relatively rare type cancer with a rate of 1% of all cancer types (Robert-Koch-Institut, RKI). About 250,000 persons fell ill with malignant brain tumors worldwide in 2012 (incidence rate: 3.4/100,000 persons; data source: IARC GLOBOCAN). The incidence for acoustic neuroma is 1 per 100,000 persons per year.

A summarizing evaluation of the publications on cancer due to exposure to radiofrequency electromagnetic fields has been conducted by an expert group of the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). Radiofrequency electromagnetic fields were classified into group 2B "possibly carcinogenic" to humans (IARC Monographs Vol. 102, p.419). The evidence of an increased risk based on the epidemiological studies (e.g., Interphone study) was rated as limited. Also the evidence of animal studies was evaluated as limited. Only weak evidence for possible mechanisms of action between effects of radiofrequency electromagnetic fields and the occurrence of cancer was observed in in vitro studies. According to the IARC evaluation, there was not sufficient evidence found for an association between exposure to radiofrequency electromagnetic fields and the risk for other cancer types (e.g., leukemia, lymphoma, breast cancer, testicular tumor).

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has concluded in their evaluation (2011) based on epidemiological and animal studies that an increase of cancer risk in adults is unlikely within 10-15 years after first use of mobile phones use. Data for childhood tumors and for periods beyond 15 years were lacking at the time of the evaluation.

Because of the increasing use of mobile phones and the lack of studies with longer observation periods of more than 15 years, the WHO (WHO fact sheet 193, WHO research agenda, p.12) has recommended additional research especially for long-term exposure to mobile phones (e.g., COSMOS study, CEFALO study, and MOBI-KIDS study). Especially children and adolescents should be studied because they will be exposed longer during their lifetime than today’s adults.

The Scientific Committee on Emerging and Newly Identified Health Risks of the European Commission (SCENIHR) stated in their opinion (2015, p.5) that overall epidemiological studies on mobile phone use did not show an increased risk for brain tumors. Some studies suggested an increased risk for glioma and acoustic neuroma. However, the results of cohort studies and incidence time trend studies did not support an increased risk for glioma and the possibility of an association with acoustic neuroma remains open. According to SCENIHR, there is no evidence of an increased risk for other cancer types in adults and children.

The German Commission on Radiological Protection (SSK) stated in their evaluation (2011, p.8 in German only) that there is insufficient evidence for an association between cancer risk and mobile communication exposure. The German Federal Office for Radiation Protection stated on the basis of epidemiological studies on mobile phone use that there is no increased cancer risk in adults.

More information and an overview of all studies on mobile-communication related exposure and cancer are available for epidemiological studies and for experimental studies. Further information and an overview of studies on children and young animals are available for epidemiological studies and for experimental studies.