Epidemiological study (observational study)

Mobile phone use, exposure to radiofrequency electromagnetic field, and brain tumour: a case-control study.

Published in: Br J Cancer 2008; 98 (3): 652-659

Aim of study (acc. to author)

The relation between mobile phone use and brain tumor was investigated in a population-based case-control study in Japan. The study is part of the INTERPHONE project.

Further details

Regular mobile phone use was defined as use at least once a week for 6 months one year before diagnosis. Exposure was assessed by following the protocol of the INTERPHONE study using a questionnaire. Furthermore, a new approach was used for estimating the specific absorption rate (SAR) inside the tumor based on a head model taking account of spatial relationships between tumor localisation and intracranial radiofrequency distribution (Nagaoka et al, 2004). Three SAR-derived exposure indices (mean maximal SAR, cumulative maximal SAR-year, and cumulative maximal SAR-hour) were calculated and categorized in four quartiles.

Endpoint/type of risk estimation

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

Exposure

Assessment

Exposure groups

Reference group 1 mobile phone use: non-user
Group 2 mobile phone use: regular user
Reference group 3 cumulative length of use in years: non-user
Group 4 cumulative length of use in years: lowest
Group 5 cumulative length of use in years: mid-low
Group 6 cumulative length of use in years: mid-high
Group 7 cumulative length of use in years: highest
Reference group 8 cumulative call time in hours: non-user
Group 9 cumulative call time in hours: lowest
Group 10 cumulative call time in hours: mid-low
Group 11 cumulative call time in hours: mid-high
Group 12 cumulative call time in hours: highest
Reference group 13 type of mobile phone used: non-user
Group 14 type of mobile phone used: analog and digital
Group 15 type of mobile phone used: digital
Reference group 16 tumor laterality and side of mobile phone use: no or contralateral use
Group 17 tumor laterality and side of mobile phone use: ipsilateral
Reference group 18 tumor laterality and side of mobile phone use: no or ipsilateral use
Group 19 tumor laterality and side of mobile phone use: contralateral
Reference group 20 mean maximal SAR: non-exposed
Group 21 mean maximal SAR: lowest
Group 22 mean maximal SAR: mid-low
Group 23 mean maximal SAR: mid-high
Group 24 mean maximal SAR: highest
Reference group 25 mean maximal SAR: non-exposed
Group 26 mean maximal SAR: < 0.001 W/kg
Group 27 mean maximal SAR: 0.001 - 0.01 W/kg
Group 28 mean maximal SAR: ≥ 0.01 W/kg
Reference group 29 cumulative maximal SAR-year: non-exposed
Group 30 cumulative maximal SAR-year: lowest
Group 31 cumulative maximal SAR-year: mid-low
Group 32 cumulative maximal SAR-year: mid-high
Group 33 cumulative maximal SAR-year: highest
Reference group 34 cumulative maximal SAR-year: non-exposed
Group 35 cumulative maximal SAR-year: < 0.001 W/kg
Group 36 cumulative maximal SAR-year: 0.001 - 0.01 W/kg
Group 37 cumulative maximal SAR-year: 0.01 - 0.1 W/kg
Group 38 cumulative maximal SAR-year: ≥ 0.1 W/kg
Reference group 39 cumulative maximal SAR-hour: non-exposed
Group 40 cumulative maximal SAR-hour: lowest
Group 41 cumulative maximal SAR-hour: mid-low
Group 42 cumulative maximal SAR-hour: mid-high
Group 43 cumulative maximal SAR-hour: highest
Reference group 44 cumulative maximal SAR-hour: non-exposed
Group 45 cumulative maximal SAR-hour: < 0.1 W/kg
Group 46 cumulative maximal SAR-hour: 0.1 - 1 W/kg
Group 47 cumulative maximal SAR-hour: 1 - 10 W/kg
Group 48 cumulative maximal SAR-hour: ≥ 10 W/kg

Population

  • Group:
    • men
    • women
  • Age: 30–69 yr
  • Observation period: December 2000 - November 2004
  • Study location: Japan (Tokyo)

Case group

Control group

  • Selection:
    • population-based
  • Matching:
    • sex
    • area
    • 5-years age group

Study size

Cases Controls
Eligible 455 1,122
Participants 322 683
Other: glioma: 88 cases; meningioma: 132 cases; pituitary adenoma: 102 cases
Statistical analysis method:
  • conditional logistic regression
( adjustment:
  • age
  • sex
  • educational level, marital status
)

Conclusion (acc. to author)

No consistent increase was observed in the overall risk of glioma, meningioma and pituitary adenoma among mobile phone users. No increasing trend in risk in relation to cumulative length of use or cumulative call time was foung. The results of the SAR-derived exposure indices also showed no substantial increased risk for glioma or meningioma.

Study funded by

  • Ministry of Internal Affairs and Communications, Japan

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