Epidemiological study (observational study)

Cellular and cordless telephones and the risk for brain tumours epidem.

By: Hardell L, Hallquist A, Hansson Mild K, Carlberg M, Pahlson A, Lilja A

Published in: Eur J Cancer Prev 2002; 11 (4): 377-386

Aim of study (acc. to author)

A population-based case-control study was conducted in Sweden to investigate the risk of brain tumors and the use of cellular telephones and cordless telephones.

Further details

Further analyses of the database of this case-control study are published in the publications 9520, 9361, 11953, and 12393.
Subjects who started their use of a mobile phone or cordless phone within one year prior diagnosis were classified as unexposed.

Endpoint/type of risk estimation

brain tumor

Type of risk estimation:

incidence

(odds ratio (OR))

Exposure

- mobile communications
- analog mobile phone
- digital mobile phone
- GSM
- NMT
- cordless phone
- personal

Assessment

questionnaire: type of phone, years of use, brand name, first part of number (to differentiate between analog and digital), mean number and minutes of daily calls, use in car with fixed external antenna or hands-free device, ear most frequently used during calls
interview: supplementing data
calculation: cumulative use in hours

Exposure groups

Group	Description
Reference group 1	unexposed
Group 2	analog, 450 MHz, > 1 year latency
Group 3	analog, 450 MHz, > 5 years latency
Group 4	analog, 450 MHz, > 10 years latency
Group 5	analog, 900 MHz, > 1 year latency
Group 6	analog, 900 MHz, > 5 years latency
Group 7	analog, 900 MHz, > 10 years latency
Group 8	analog, all, > 1 year latency
Group 9	analog, all, > 5 years latency
Group 10	analog, all, >10 years latency
Group 11	analog, ≤ 85 h, > 1 year latency
Group 12	analog, ≤ 85 h, > 5 years latency
Group 13	analog, ≤ 85 h, >10 years latency
Group 14	analog, > 85 h, > 1 year latency
Group 15	analog, > 85 h, > 5 years latency
Group 16	analog, > 85 h, > 10 years latency
Group 17	digital, all, > 1 year latency
Group 18	digital, all, > 5 years latency
Group 19	digital, all, >10 years latency
Group 20	digital, ≤ 55 h, > 1 year latency
Group 21	digital, ≤ 55 h, > 5 years latency
Group 22	digital, ≤ 55 h, >10 years latency
Group 23	digital, > 55 h, > 1 year latency
Group 24	digital, > 55 h, > 5 years latency
Group 25	digital, > 55 h, >10 years latency
Group 26	cordless, all, > 1 year latency
Group 27	cordless, all, > 5 years latency
Group 28	cordless, all, > 10 years latency
Group 29	cordless, ≤ 183 h, > 1 year latency
Group 30	cordless, ≤ 183 h, > 5 years latency
Group 31	cordless, ≤ 183 h, > 10 years latency
Group 32	cordless, > 183 h, > 1 year latency
Group 33	cordless, > 183 h, > 5 years latency
Group 34	cordless, > 183 h, > 10 years latency

Population

Group:
- men
- women
Age: 20–80 years
Observation period: January 1997 - June 2000
Study location: Sweden (Uppsala/Örebro, Stockholm, Linköping and Göteborg regions)

Case group

Characteristics: brain tumor, histopathologically verified
Data source: Cancer Registry
Exclusion criteria: deceased

Control group

Selection:
- population-based
Matching:
- sex
- area
- 5-years age group
- case:control = 1:1

Study size

	Cases	Controls
Eligible	1,617	-
Contacted	1,617	1,617
Participants	1,429	1,470
Participation rate	88 %	91 %
Evaluable	1,303	1,470

Other:

1303 complete pairs were used for statistical analysis.

Statistical analysis method:

conditional logistic regression
multivariate analysis

Results (acc. to author)

17.3 % of the cases and 14.8 % of the controls reported the use of analog cellular phones, 29.6 % of the cases and 29.5 % of the controls the use of digital cellular phones, and 28.1 % of the cases and 26.9 % of the controls the use of cordless phones. An increased risk for brain tumor and the use of analog cellular phones was found. For digital cellular phones and cordless phones no significantly increased risk was observed overall within a 5-year latency period.

Limitations (acc. to author)

The median time of use was 3 years for digital cellular phones, 5 years for cordless phones and 7 years for analog cellular phones.

Study funded by

Cancer och Allergifonden (Cancer and Allergy Foundation), Sweden
Örebro Cancer Fund, Sweden
Swedish Work Environment Fund
Telia, Sweden

Comments on this article

Hallberg O (2005): Hearing problems and acoustic neuroma cancer in Sweden

Prasad M et al. (2017): Mobile phone use and risk of brain tumours: a systematic review of association between study quality, source of funding, and research outcomes
Leitgeb N (2015): Synoptic Analysis of Epidemiologic Evidence of Glioma Risk from Mobile Phones
Leitgeb N (2014): Synoptic Analysis of Epidemiologic Evidence of Brain Cancer Risks from Mobile Communication
Lagorio S et al. (2014): Mobile phone use and risk of intracranial tumors: A consistency analysis
Hardell L et al. (2013): Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997-2003 and 2007-2009 and use of mobile and cordless phones
Myung SK et al. (2009): Mobile phone use and risk of tumors: a meta-analysis
Hardell L et al. (2009): Mobile phones, cordless phones and the risk for brain tumours
Klaeboe L et al. (2007): Use of mobile phones in Norway and risk of intracranial tumours
Lahkola A et al. (2007): Mobile phone use and risk of glioma in 5 North European countries
Hepworth SJ et al. (2006): Mobile phone use and risk of glioma in adults: case-control study
Lönn S et al. (2006): Mobile phone use and risk of parotid gland tumor
Lahkola A et al. (2006): Meta-analysis of mobile phone use and intracranial tumors
Hardell L et al. (2006): Pooled analysis of two case-control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997-2003
Schüz J et al. (2006): Cellular phones, cordless phones, and the risks of glioma and meningioma (Interphone Study Group, Germany)
Hardell L et al. (2006): Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003
Hardell L et al. (2006): Case-control study of the association between the use of cellular and cordless telephones and malignant brain tumors diagnosed during 2000-2003
Hardell L et al. (2005): Case-Control Study on Cellular and Cordless Telephones and the Risk for Acoustic Neuroma or Meningioma in Patients Diagnosed 2000-2003
Christensen HC et al. (2005): Cellular telephones and risk for brain tumors: a population-based, incident case-control study
Lönn S et al. (2005): Long-term mobile phone use and brain tumor risk
Hardell L et al. (2004): Cellular and cordless telephone use and the association with brain tumors in different age groups
Lönn S et al. (2004): Mobile Phone Use and the Risk of Acoustic Neuroma
Hardell L et al. (2003): Further aspects on cellular and cordless telephones and brain tumours
Hardell L et al. (2002): Case-control study on the use of cellular and cordless phones and the risk for malignant brain tumours
Auvinen A et al. (2002): Brain tumors and salivary gland cancers among cellular telephone users
Hardell L et al. (2001): Ionizing radiation, cellular telephones and the risk for brain tumours
Inskip PD et al. (2001): Cellular-telephone use and brain tumors
Muscat JE et al. (2000): Handheld cellular telephone use and risk of brain cancer
Hardell L et al. (2000): Case-control study on radiology work, medical x-ray investigations, and use of cellular telephones as risk factors for brain tumors
Hardell L et al. (1999): Use of cellular telephones and the risk for brain tumours: A case-control study