Epidemiological study (observational study)

Mobile phone use and risk of glioma in 5 North European countries.

Published in: Int J Cancer 2007; 120 (8): 1769-1775

Aim of study (acc. to author)

The collaborative population-based case-control study was conducted in five North European countries (Denmark, Finland, Norway, Sweden, Southeast England) to investigate the possible association of glioma with use of mobile phones.
This study is part of the INTERPHONE project.

Further details

The Swedish, Danish and British studies have been published previously (publication 11648, publication 11887, and publication 13154). Furthermore, the authors recently reported also a collaborative analysis of acoustic neuromas based on these studies (publication 12419).
Regular use of a mobile phone was defined as at least once a week for at least six months.

Endpoint/type of risk estimation

Type of risk estimation:
  • incidence
(odds ratio (OR))

Exposure

Assessment

  • Type of assessment: Individual
  • interview: mobile phone use, including start and end dates of use, types of phones used and the frequency of use, laterality, use of hands-free equipment, and other circumstances of use such as type of telephone network
  • calculation: lifetime cumulative numbers of hours of phone use and numbers of calls

Exposure groups

Reference group 1 never or nonregular use
Group 2 regular use
Group 3 years since first use: 1.5-4
Group 4 years since first use: 5-9
Group 5 years since first use: ≥10
Group 6 lifetime years of use: 0.5-4
Group 7 lifetime years of use: 5-9
Group 8 lifetime years of use: ≥ 10
Group 9 cumulative number of calls: < 2172
Group 10 cumulative number of calls: 2172-7792
Group 11 cumulative number of calls: > 7792
Group 12 cumulative hours of use: < 125
Group 13 cumulative hours of use: 125-503
Group 14 cumulative hours of use: > 503
Group 15 cumulative number of calls by time since first use: < 10 years
Group 16 cumulative number of calls by time since first use: ≥ 10 years (≤ 1512 calls)
Group 17 cumulative number of calls by time since first use: ≥ 10 years (> 1512 calls)
Group 18 cumulative hours of use by time since first use: < 10 years
Group 19 cumulative hours of use by time since first use: ≥ 10 years (≤ 75 hours)
Group 20 cumulative hours of use by time since first use: ≥ 10 years (> 75 hours)
Group 21 analogue phone use
Group 22 digital phone use
Reference group 23 nonregular use or contralateral side of tumor and phone use
Group 24 ipsilateral, years since first use: 1.5-4
Group 25 ipsilateral, years since first use: 5-9
Group 26 ipsilateral, years since first use: ≥10
Reference group 27 nonregular use or ipsilateral side of tumor and phone use
Group 28 contralateral, years since first use: 1.5-4
Group 29 contralateral, years since first use: 5-9
Group 30 contralateral, years since first use: ≥10

Population

  • Group:
    • men
    • women
  • Age: 20–69 yr
  • Observation period: September 1999 - February 2004
  • Study location: Denmark, Finland (excluding Northern Lapland and Aland), Norway (the Southern and Middle parts), Sweden (Umea, Stockholm, Gothenburg, and Lund regions), United Kingdom (Thames region of Southeast England)

Case group

Control group

  • Selection:
    • population-based
    • registry-based
  • Matching:
    • sex
    • age
    • area

Study size

Cases Controls
Eligible 2,530 6,581
Participants 1,521 3,301
Participation rate 60 50
Statistical analysis method:
  • conditional logistic regression
( adjustment:
  • 5-year age group
  • sex
  • residential area
  • country
)

Conclusion (acc. to author)

No evidence of increased risk of glioma related to regular mobile phone use was found. No significant association was found across categories with duration of use, years since first use, cumulative number of calls or cumulative hours of use. No increased risks was found when analogue and digital phones were analyzed separately.
An increased risk for tumour ipsilateral to side of phone use was found for more than 10 years of mobile phone use (group 26). The indication of increased risk in relation to reported ipsilateral mobile phone use for more than 10 years duration may be due to either chance or causal effect or information bias.

Study funded by

  • European Union (EU)/European Commission
  • Academy of Finland
  • Swedish Research Council (VR)
  • Emil Aaltonen Foundation, Finland
  • GSM Association, UK/Ireland
  • Mobile Manufacturers Forum (MMF), Belgium
  • International Union against Cancer (UICC; Union Internationale Contre le Cancer), Switzerland
  • Mobile Telecommunications and Health Research (MTHR), UK
  • Doctoral Programs for Public Health (DPPH), Finland
  • Quality of Life and Management of Living Resources program of European Union

Related articles