Epidemiological study (observational study)

Cellular phone use and risk of benign and malignant parotid gland tumors--a nationwide case-control study epidem.

By: Sadetzki S, Chetrit A, Jarus-Hakak A, Cardis E, Deutch Y, Duvdevani S, Zultan A, Novikov I, Freedman L, Wolf M

Published in: Am J Epidemiol 2008; 167 (4): 457-467

Aim of study (acc. to author)

The association between cellular phone use and parotid gland tumors was investigated in a nationwide case-control study in Israel. This study is part of the INTERPHONE project.

Further details

The association between laterality of tumor and side of cellular phone use was assessed by case-only analysis (including only cases who were regular users reporting on a single dominant side of use) and by case-control analysis stratified to ipsilateral and contralateral use.
Regular use of a mobile phone was defined as at least once a week for at least six months.

Endpoint/type of risk estimation

benign and malignant parotid gland tumors

Type of risk estimation:

incidence

(odds ratio (OR))

Exposure

- mobile communications
- analog mobile phone
- digital mobile phone
- personal

Assessment

interview: use of cellular phone, types including start and end dates, number and average duration of calls, use of headsets and hands-free devices, side of the head on which the phone was predominantly held, handedness, main area of use (urban, rural, both)

Exposure groups

Group	Description
Reference group 1	regular user: no or < 1year
Group 2	regular user: yes
Reference group 3	regular user 5 years in the past: no
Group 4	regular user 5 years in the past: yes
Reference group 5	regular user 10 years in the past: no
Group 6	regular user 10 years in the past: yes
Reference group 7	time since start use: never or < 1 year
Group 8	time since start use: 1 - 4.9 years
Group 9	time since start use: 5 - 9.9 years
Group 10	time since start use: ≥ 10 years
Reference group 11	duration of use: never or < 1 year
Group 12	duration of use: 1 - 4.9 years
Group 13	duration of use: 5 - 9.9 years
Group 14	duration of use: ≥ 10 years
Reference group 15	cumulative number of calls: nonusers or < 1 year
Group 16	cumulative number of calls: ≤ 5,479
Group 17	cumulative number of calls: ≥ 5,480
Group 18	cumulative number of calls: ≥ 18,997
Reference group 19	cumulative call time: nonusers or < 1 year
Group 20	cumulative call time: ≤ 266.3 hours
Group 21	cumulative call time: > 266.3 hours
Group 22	cumulative call time: > 1,035 hours
Reference group 23	cumulative call time by time since start use: nonusers or < 1 year
Group 24	cumulative call time by time since start use: < 5 years, ≤ 266.3 hours
Group 25	cumulative call time by time since start use: < 5 years, > 266.3 hours
Group 26	cumulative call time by time since start use: ≥ 5 years, ≤ 266.3 hours
Group 27	cumulative call time by time since start use: ≥ 5 years, > 266.3 hours
Reference group 28	cumulative number of calls by time since start use: nonusers or < 1 year
Group 29	cumulative number of calls by time since start use: < 5 years, ≤ 5479
Group 30	cumulative number of calls by time since start use: < 5 years, > 5479
Group 31	cumulative number of calls by time since start use: ≥ 5 years, ≤ 5479
Group 32	cumulative number of calls by time since start use: ≥ 5 years, > 5479
Reference group 33	regular users only, time since start use: 1 - 4.9 years
Group 34	regular users only, time since start use: 5 - 9.9 years
Group 35	regular users only, time since start use: ≥ 10 years
Reference group 36	regular users only, duration of use: 1 - 4.9 years
Group 37	regular users only, duration of use: 5 - 9.9 years
Group 38	regular users only, duration of use: ≥ 10 years
Reference group 39	regular users only, cumulative number of calls: ≤ 5,479
Group 40	regular users only, cumulative number of calls: 5,480 - 18,996
Group 41	regular users only, cumulative number of calls: ≥ 18,997
Reference group 42	regular users only, cumulative call time: ≤ 266.3 hours
Group 43	regular users only, cumulative call time: 266.4 - 1034.9 hours
Group 44	regular users only, cumulative call time: ≥ 1035 hours

Population

Group:
- men
- women
Age: ≥ 18 years
Observation period: January 2001 - December 2003
Study location: Israel

Case group

Characteristics: benign or malignant parotid gland tumor, histologically or cytologically confirmed
Data source: all 22 otolaryngology departments of hospitals in Israel

Control group

Selection:
- population-based
Matching:
- sex
- age
- continent of birth
Exclusion criteria: not living in Israel, mentally disabled

Study size

	Cases	Controls
Eligible	531	1,920
Participants	460	1,266
Participation rate	87 %	66 %

Other:

402 benign and 58 malignant tumors

Statistical analysis method:

logistic regression
trend tests

(adjustment:

age
sex
year of interview

)

Results (acc. to author)

Cellular phone users in Israel are exceptionally heavy users compared to cellular phone users in other countries participating in the Interphone study.
No increased risk of parotid gland tumors was observed for ever having been a regular cellular phone user for the entire group. For ipsilateral use, the odds ratios in the highest category of cumulative number of calls and call time were significantly elevated.
The authors concluded that the results suggest a relation between long-term and heavy cellular phone use and parotid gland tumors. This association was seen in analyses restricted to regular users, analyses of laterality of cellular phone use, and analyses of area of main use (urban, rural, or both) .

Study funded by

European Union (EU)/European Commission
GSM Association, UK/Ireland
International Union against Cancer (UICC; Union Internationale Contre le Cancer), Switzerland
Israel Cancer Association (ICA)
Mobile Manufacturers Forum (MMF), Belgium

de Siqueira EC et al. (2017): Does cell phone use increase the chances of parotid gland tumor development? A systematic review and meta-analysis
Siqueira EC et al. (2016): Cell phone use is associated with an inflammatory cytokine profile of parotid gland saliva
Al-Qahtani K (2016): Mobile Phone Use and the Risk of Parotid Gland Tumors: A Retrospective Case-Control Study
Lagorio S et al. (2014): Mobile phone use and risk of intracranial tumors: A consistency analysis
Shu X et al. (2012): Incidence trends of malignant parotid gland tumors in Swedish and nordic adults 1970 to 2009
Söderqvist F et al. (2012): Use of wireless phones and the risk of salivary gland tumours: a case-control study
de Vocht F (2011): Cell phones and parotid cancer trends in England
Duan Y et al. (2011): Correlation between cellular phone use and epithelial parotid gland malignancies
Czerninski R et al. (2011): Risk of parotid malignant tumors in Israel (1970-2006)
Goldwein O et al. (2010): The influence of handheld mobile phones on human parotid gland secretion
Myung SK et al. (2009): Mobile phone use and risk of tumors: a meta-analysis
Lahkola A et al. (2007): Mobile phone use and risk of glioma in 5 North European countries
Lönn S et al. (2006): Mobile phone use and risk of parotid gland tumor
Vrijheid M et al. (2006): Validation of short term recall of mobile phone use for the Interphone study
Schüz J et al. (2006): Cellular phones, cordless phones, and the risks of glioma and meningioma (Interphone Study Group, Germany)
Schoemaker MJ et al. (2005): Mobile phone use and risk of acoustic neuroma: results of the Interphone case-control study in five North European countries
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
Lönn S et al. (2004): Mobile Phone Use and the Risk of Acoustic Neuroma
Hardell L et al. (2004): No association between the use of cellular or cordless telephones and salivary gland tumours
Christensen HC et al. (2004): Cellular telephone use and risk of acoustic neuroma
Auvinen A et al. (2002): Brain tumors and salivary gland cancers among cellular telephone users
Cardis E et al. (1999): International Case-Control Study of Adult Brain, Head and Neck Tumours: Results of the Feasibility Study