T

here have long been fears in the community

about whether the use of mobile phones could

lead to an increase in the frequency of brain

tumours. However, our analysis of data collected

by The New Zealand Cancer Registry between

1995 and 2010 has found that the risk of developing a brain

tumour has not changed signiicantly despite the increased use

of mobile phones during that time.

In fact, for those aged 10–69 years there has been a decrease

of about 1% per year. In people aged over 70 years there was an

increase in some types of brain cancer, but this has been seen

in other countries and is likely to be due to improved diagnosis.

Our study, published in theAustralian and New Zealand

Journal of Public Health(tinyurl.com/ptynwqe), adds to

existing evidence against a substantially increased risk in mobile

phone users, and is consistent with most similar studies

conducted in other countries. However, a study of this type

cannot exclude the possibility of a small risk, or a risk limited

to a certain subtype of cancers, or a risk that only arises after

more than 15 years of phone use.

Put that way, our research results sound pretty simple and

straightforward, but reaching those conclusions took a great

deal of thought and hard work.

Stella had completed the 3 years of the Bachelor of Health

Science program and had chosen to do an Honours year, which

requires a research dissertation. She was interested in epidemi-

ology, and Mark suggested she examine whether there been

an increase in the incidence of brain cancers in New Zealand

in recent years. This is an important question because almost

everybody uses a cell phone these days, and the idea that cell

phones increase brain cancers because of their electromagnetic

radiation is a familiar one.

While the popular concept of science is that the develop-

ment of such a scientiic study involves deep contemplation and

challenging original thought, in practice the questions asked

when selecting a study are often are very practical. Can we get

data? Do we need funding? What do we do about ethical

approval?

The mobile phone study was only feasible because New

Zealand, like most other developed countries, has a national

cancer registry: that is, a system by which every newly diag-

nosed cancer in the country is reported to a group within the

Ministry of Health.

So we asked the cancer registry to give us information on

every person with a brain cancer diagnosed and recorded in

New Zealand between 1985 and 2010 (the most recent year

available) as a simple Excel spreadsheet. This record had their

age, gender, date of diagnosis, and details about the cancer

such as its pathology (there are several different types of brain

cancer) and its location within the brain. The information we

34 | APRIL 2016

DData Caps

Brain Cancer

Concerns

MARK ELWOOD & STELLA KIM

Extensive health data records

in New Zealand have revealed

whether brain cancer rates have

changed as a result of radiation

emitted by mobile phones.

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