Dr. Leszczynski is one of the world's leading biologists who researches the effects of radiofrequency radiation for the Finnish government. At least he did until the Finnish government defunded his laboratory. He was one of 31 experts invited in 2011 by the World Health Organization's (WHO) International Agency for Research on Cancer to review the cancer risks of exposure to wireless radiation. The results of this expert review was that WHO classified radiofrequency energy, especially cell phone radiation, as "possibly carcinogenic" in humans (i.e., Group 2B). Dr. Leszczynski has subsequently reported that some of the group wanted a "probably carcinogenic" or Group 2A classification.
Dr. Leszczynski has been writing an occasional column that is published on the Washington Times web site. For his latest article, he asked six experts including two of the WHO Interphone Study investigators to comment on the United Kingdom's Million Women Study. His interest in this study is because the study's authors interpreted the absence of evidence for increased brain cancer risk to mean that cell phone radiation does not cause cancer.
One of the experts interviewed for this column was the former director of the WHO's EMF Project. He defends the Million Women Study and argues based on the results that cell phone radiation does not cause cancer. In contrast, the other five experts including myself criticize the study and dismiss its relevance to the cancer debate.
Despite its shortcomings, the study found significant evidence that cell phone use was associated with increased risk of acoustic neuroma, a rare, non-malignant tumor on the nerve from the ear to the brain.
The Million Women Study … shoddy
design … shoddy results … shoddy conclusions
Dariusz
Leszczynski, Washington Times Communities, Oct 3, 2013
HELSINKI,
Finland, October 3, 2013 —The only two epidemiological cohort studies in
existence examining the link between cell phone radiation exposures and brain
cancer have embarrassingly poor design.
The two
cohorts were established in Denmark and in UK. The original purpose was not to
study cell phone radiation effects but other health problems. At some point in
designing cohorts, scientists decided to ask questions about cell phone use
and, as an aside, to examine brain cancer risk.
The
problem is that the questions concerning cell phone use were not well thought
out. It seems that epidemiologists did not care at all about details of
exposure to cell phone radiation. They just wanted to know it - “roughly”.
In the
first cohort, called ‘Danish Cohort’, the information on exposure of persons to
cell phone radiation is completely useless for the purpose of determining
whether causality exists between radiation exposure and cancer (for details see
letters to the British Medical Journal and The Scientist Magazine story).
In the
spring of 2013, the results from the second cohort were published and called The Million Women Study. As seen
from the description of the study, its primary goal was to examine the effects
of hormone replacement therapy in women over 50 years of age.
This, by
design, indicates that the results of this study apply only to a certain sex
(females) and age (over 50) group and can not be freely extrapolated to the
cell phone users as a whole. Furthermore, period of the exposure to cell phone
radiation examined in The Million Women Study is far too short to be relevant
when examining causality link between cell phone radiation and cancer.
The information
about cell phone radiation exposures obtained for the study was as follows
(quote from the study): “Women in the study have been asked twice about mobile
phone use. In a survey conducted between 1999 and 2005 (to which about 65% of
women recruited in 1996–2001 replied [sic!]), women were asked: ‘About how
often do you use a mobile phone?’, and given three options to respond: ‘never’,
‘less than once a day’, ‘every day’; and ‘For how long have you used one?’
(participants were asked to provide total years of use).”
The
authors did not obtain information about cell phone usage per day or week. Cell
phone users talking on the phone for few minutes or for few hours per week were
analyzed together. When considering the latency of brain cancer, the follow-up
period was far too short to provide relevant and reliable information. This
extremely limited information about the exposures to cell phone radiation is
absolutely inadequate to determine whether exposures have, or have not, causal
link with cancer.
The
inadequacy of the collected the information on the exposure is very disturbing.
It is like scientists evaluating the health risk in smokers and not asking how
many cigarettes per day someone smokes.
The
Million Women Study has shoddy exposure design leading to shoddy results and
ending with shoddy conclusions.
The
Million Women Study is, similarly with the Danish Cohort, yet another example
of the complete failure of epidemiologists to design scientifically relevant
study on cell phone radiation and brain cancer.
It is
embarrassing to hear that some scientists consider the “epidemiological
failure”, called The Million Women Study, as a “well designed” research.
Forbes’
Magazine blogger, Geoffrey Kabat of the Albert Einstein College of Medicine in
New York City, in his recent post says about The Million Women Study: “The
strengths of this design are two-fold.
First, it follows the actual temporal sequence, with exposure preceding
disease. Second, since information on
exposure is obtained before the onset of illness, this information cannot be
biased (distorted) by the presence of illness.”
Indeed,
these could be the strengths of the study if the information on exposures was
relevant.
Mr. Kabat
writes also that: “Because of its large size and prospective design, the
Million Women Study results represent an important contribution.”
Big is not
always beautiful, especially when one side of the examined equation, the
radiation exposure data, are shoddy.
I asked
also opinions from the few prominent scientists about The Million Women Study.
Here are their opinions, directly as provided via e-mails:
Michael
Repacholi, retired Head of the WHO EMF Project, agrees with Geoffrey Kabat that
the Million Women Study is a valuable proof of no cancer risk:
“This is a
very large, well-conducted cohort study showing no increased incidence of
glioma or meningioma with mobile phone use of 10 or more years. However, the
study reported a trend of increasing risk of acoustic neuroma. When the results
were combined with the Danish cohort study, that had a much larger number of
these tumours, no statistical increase was found with mobile phone use of 10 or
more years. Aside from the obvious difficulties in accurately assessing people’s
exposure to mobile phones, the evidence from well-conducted epidemiological and
animal studies is now establishing that mobile phone use does not cause or
increase the incidence of head or neck cancers.”
The above
opinion of Michael Repacholi should be also viewed in the context of his recent
criticism of epidemiology. His opinion was that epidemiology is unable to
provide reliable information on causality link between cell phone radiation and
brain cancer. As Mr. Repacholi said in his Guest Blog on BRHP: “my concern is
that there is an over-reliance on epidemiology studies.”
However,
epidemiologists were cautious and did not consider the evidence provided by The
Million Women Study to be as great as Kabat and Repacholi thought.
Michael
Kundi of the Medical University of Vienna, Austria, considers it a very good
idea to use the existing large cohorts to study cell phone radiation and cancer
issue. However, he points out that the authors of the Million Women Study did
not do a good job:
“It is
definitely worthwhile to try and use a large cohort of people that are
available for investigations like the cohort of the Million Women Study. This
cohort has been used for many important health issues and will continue to be
used for a variety of research questions. Having said this, I regret to say
that the authors have not put much thought into the issue of mobile phone use
and brain tumors. It is almost impossible to study induction of brain tumors
because of the short observation period. That is, most if not all of the tumors
diagnosed during the follow-up must have already existed at the time of
commencing use of a mobile. This leaves us with studying effects on tumor
growth rate and/or progression. In the case of glioma the peculiarities of the
relationship of incidences with age have to be considered. In this cohort there
are only women and they are in a narrow age range of about 60 years. The
consequence of this fact is that if mobile phone use leads to an increased
growth rate of the tumor and therefore an earlier diagnosis the risk estimate
must be low or even less than one (because at older age the incidence is
declining). The situation for acoustic neuroma is different because the
age-incidence function differs from that of glioma.”
Bruce
Armstrong of the Sydney University, Australia, considers that The Million Women
Study is insufficient to think of down-grading the IARC classification of cell
phone radiation from the current possible carcinogen category to lower one:
“A total
of 1,261 primary intracranial neoplasms were diagnosed during follow-up, which
is sufficient to make a potentially worthwhile contribution to literature on
mobile phone use and brain tumours. Some 50,000 invasive neoplasms at other
sites were also diagnosed, which can also contribute to knowledge about the
relationship between other cancers and mobile phone use. Of the intracranial
tumours investigated (glioma, meningioma, pituitary tumours and acoustic
neuroma) only risk of acoustic neuroma was increased in women who were longer
term users of a mobile phone. This result is coherent with results from the
most recent case-control studies of mobile phone use and acoustic neuroma but
not with the absence of increase in risk of acoustic neuroma reported from the
Danish cohort study of mobile phone subscribers. While this study adds to the evidence on the
relationship between mobile phone use and intracranial tumours, it does not add
sufficiently, in my opinion, to shift in either direction the IARC’s conclusion
that there is limited evidence in humans for carcinogenicity of radiofrequency
radiation.”
Joel
Moskowitz of the University of California at Berkeley has also serious doubts
about the design and quality of the outcome of The Million Women Study:
“With
regard to investigating the association between cell phone use and subsequent
tumor risk (which was not the primary purpose of the “million women” study),
this study had several major shortcomings which would undermine its ability to
find this association. First, cell phone
use was measured only at the beginning of the study, and it was assessed too
crudely to expect to find an association with tumor risk. When women enrolled
in the study, they were asked how many years they used a cell phone, and if
they did, whether they used it daily or less than daily. The researchers had no
follow up assessments to determine whether the women continued to use their
cell phones over time so they had to assume that cell phone users continued to
use their cell phones. More importantly, the researchers could not assess how
much time the women spent on a cell phone either before or during the course of
the study so women who used a few minutes almost every day at baseline would be
lumped together with women who used their phone a half hour or more per day. Second, the study failed to assess cordless
phone use which likely exceeded cell phone use among these women due to the
high cost of cell phone minutes during this period. Cordless phone use has been found in other
research to increase brain tumor risk. Third, brain tumors can take several
decades to develop and few women in this study had used their cell phones for
ten or more years. Fourth, about 40% of
the 1.3 million women who participated in the study were excluded from the cell
phone analyses—most because they failed to provide any cell phone information.
This large loss of research participants limits how generalizable the study
findings are and could have biased the results. Despite these major
shortcomings, the study reported a statistically significant doubling of risk
of acoustic neuroma, a tumor on the nerve from the ear to the brain, among
those who used cell phones for 10 or more years. Moreover, this association was
related to the number of years of cell phone use.”
Mark
Elwood, of the University of Auckland in New Zealand is not convinced that the
provided evidence is sufficiently reliable to convince the scientists and the
general public alike:
“These
scientists took the opportunity of asking a few questions about cell phone use
in the huge British ‘Million Women’ study, where women attending breast cancer
screening clinics were invited. Over the next 10 or more years, women (average
age 59) who reported the most use of cellphones had the same risk of developing
brain cancers than women who did not use cellphones at the time that was asked (and also, the
same risk of all cancers, and of 18 major types of cancer). So, another of many
studies showing no risk from using cellphones, but like all other studies, it
can’t prove that there’s no risk. In the many analyses, there was an increased
risk of one rather rare tumor, based on only 8 cases; but that was acoustic
neuroma, a tumor of the nerve to the ear, and therefore in the high exposure
zone from cellphones. And the study doesn’t cover men, younger people, or risks
beyond about 10 years. So the debate will continue.”
Elisabeth
Cardis, of CREAL-Centre for Research in Environmental Epidemiology in Spain and
formerly Principal Investigator of the Interphone Project, is cautious and
considers results of The Million Women Study as too weak:
“Am a bit
surprised at the lack of mention of the acoustic neuroma results in the
conclusion - particularly since this and glioma are the two tumour types for
which their is currently the most evidence from other studies (including
Interphone and the Japanese study). It seems that the first questionnaire about
mobile phone use was asked over a long time period 1999-2005 but the follow-up
is correctly calculated from the time the questionnaire was asked. Of the 1261
intracranial CNS tumours, 754 occurred among those who reported ever use at
first questionnaire.
Only 90 of
these, however, were among women who reported using the phone every day and 100
among those who reported 10+ years of use. Numbers get even smaller when the
first 3 years of follow-up are excluded - 91 with 10+ years. It would be nice
to see results by some form of amount of use, but obviously the information
collected is very limited - ever use, daily use and number of years - but
perhaps looking at categories of daily use in different periods of time since
start … but the numbers would get very small.”
From the
above comments of prominent epidemiologists the general conclusion can be drawn
that despite the size of The Million Women cohort, the numbers of tumors are
small and the information about the cell phone use is nonexistent. Therefore,
it is not possible to draw any scientifically reliable conclusions based on the
results of The Million Women Study.
Setting up
large cohort for epidemiological study is expensive and laborious. That is why
it is indeed a very good idea to use the already existing cohorts to examine
causality link between cell phone radiation exposures and brain cancer.
However,
the radiation exposure information, both the length and the strength/intensity
of exposure, must be properly collected. Scientists working on the Danish
Cohort and The Million Women Study, failed in the study design. Radiation
exposure information collected in both cohorts is shoddy.
It is very
disappointing that yet again epidemiologists failed. They used funds to provide
us with shoddy studies. What is very worrying is the fact that these studies
were published in peer-review journals and are now considered, by some, as
“reliable scientific evidence”.
It is
simply an embarrassing show of scientific incompetence.
