Epidemiological study (observational study)

Case-control study on the use of cellular and cordless phones and the risk for malignant brain tumours epidem.

By: Hardell L, Hansson Mild K, Carlberg M

Published in: Int J Radiat Biol 2002; 78 (10): 931-936

Aim of study (acc. to author)

In this study, further analyses on the database of a Swedish case-control study (see publication 9105) were performed on the use of cellular telephones and cordless telephones and the risk of brain tumors.

Further details

Furthermore, there are additional analyses of the database of the same case-control study (publication 9105) in publications 9520, 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: malignant 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, ever, ipsilateral
Group 3	analog, 450 MHz, ever, contralateral
Group 4	analog, 450 MHz, ever, varying ipsi/contralateral
Group 5	analog, 450 MHz, ever, all
Group 6	analog, 900 MHz, ever, ipsilateral
Group 7	analog, 900 MHz, ever, contralateral
Group 8	analog, 900 MHz, ever, varying ipsi/contralateral
Group 9	analog, 900 MHz, ever, all
Group 10	analog, 450 + 900 MHz, ever, ipsilateral
Group 11	analog, 450 + 900 MHz, ever, contralateral
Group 12	analog, 450 + 900 MHz, ever, varying ipsi/contralateral
Group 13	analog, 450 + 900 MHz, ever, all
Group 14	digital, total, ipsilateral
Group 15	digital, total, contralateral
Group 16	digital, total, varying ipsi/contralateral
Group 17	digital, total, all
Group 18	cordless, total, ipsilateral
Group 19	cordless, total, contralateral
Group 20	cordless, total, varying ipsi/contralateral
Group 21	cordless, total, all

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

Control group

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

Study size

	Cases	Controls
Eligible	1,111	-
Participants	649	649
Participation rate	91 %	90 %
Evaluable	588	581

Statistical analysis method:

conditional logistic regression

(adjustment:

age
sex
socioeconomic status

)

Results (acc. to author)

18.7 % of the cases and 18.2 % of the controls reported the use of analog cellular phones, 34.7 % of the cases and 33.0 % of the controls the use of digital cellular phones, and 30.4 % of the cases and 26.5 % of the controls the use of cordless phones.
Overall, no significantly increased risk for malignant brain tumors and the use of cellular phones and cordless phones was observed. For the ipsilateral use of analog cellular telephones, significantly increased risks for all malignant brain tumors as well for astrocytoma were found.

Study funded by

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

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
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
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
Takebayashi T et al. (2006): Mobile phone use and acoustic neuroma risk in Japan
Lönn S et al. (2006): Mobile phone use and risk of parotid gland tumor
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
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Hepworth SJ et al. (2006): Mobile phone use and risk of glioma in adults: case-control study
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. (2005): Case-Control Study on Cellular and Cordless Telephones and the Risk for Acoustic Neuroma or Meningioma in Patients Diagnosed 2000-2003
Hardell L et al. (2005): Use of cellular telephones and brain tumour risk in urban and rural areas
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
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Hardell L et al. (2003): Further aspects on cellular and cordless telephones and brain tumours
Hardell L et al. (2002): Cellular and cordless telephones and the risk for brain tumours
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Hardell L et al. (2001): Ionizing radiation, cellular telephones and the risk for brain tumours
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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