Please read enclosed comments from Louis Slesin and Lloyd Morgan with regards to this study.
Eileen O'Connor
ATF:
A case-control study in Denmark and Sweden finds no association between parotid gland tumors and the use of mobile phones. The study matched 60 cases of malignant parotid gland tumors and 112 cases of benign pleomorphic adenomas with appropriate controls. They found no association, regardless of duration of mobile phone use, including use for more than 10 years' duration. American Journal of Epidemiology.
Re: [cheemf] Negative study on parotid gland tumors and cell phones
From: Bilovsky
Date: Fri, 21 Jul 2006 21:27:41 +0100
Dear Michael and CHE-EMF Discussion colleagues,
As is so common with these industry funded Interphone studies, this study is NOT A NEGATIVE finding, but suggests there is some very real concern that use of a cellphone does create a risk of parotid (salivary) gland tumors.
I was quite surprised by the findings of this latest study, as two previous studies, both independent of industry funding, had given no indication of risk.
Here is what I found as I reviewed the various tables in the study: There is a suggestive risk of pleomorphic adenomas of the parotid gland for cellphone use of more than 10 years on the same side as the tumor and a suggest trend for duration of use. For duration of "regular" use in years, OR=1.4 for less than 5 years; OR=1.5 for 5 to 9 years; OR=2.0 for more than 10 years
For duration since first "regular" use, OR=1.4 for less than 5 years; OR=1.3 for 5 to 9 years; OR=2.6 for more than 10 years.
The text of the paper remarks on these odds ratios showing increase risk stating, " . . . no estimates were significantly different from 1.0." I is incomprehensible to me that an OR=2.6 can be considered not "significantly different from 1.0."
While these results were not statistically significant they do suggest a concern. What also seems incongruous is that they do not report the combined results (i.e., without regard to duration) even though all 3 odds ratios are greater than 1.0. For the duration of "regular" use the combined number of cases was 49 and for the duration of since first "regular" use the combined number of cases was 51. I have no way of knowing if this combined number of cases would lead to a statistically significant result, but find it very curious that this was not reported.
There is no suggestive risk for malignant parotid tumors. However, there were only 26 cases from Denmark and another 34 cases from Sweden. With such small numbers it is difficult to detect anything but the largest of risks. Further, when use on the same side of the head as the tumor is analyzed the total number of cases is 16 cases. Broken into time of use the number of cases are 9, 6 and 1 for less than 5 years, 5-9 years and 10 years respectively.
When we look at the overall results for malignant tumors, Table 2 reports 13 odds ratios. They are all less than 1.0. Table 3 reports (data on same side as phone use) 7 odds ratios. Four of the 7 odds ratios are greater than 1.0.
The study remarks on the preponderance of odds ratios less than one, suggesting that this could be the result of controls who participated being more likely to use a cellphone that controls who declined participation (40% in Denmark; 38% in Sweden). Such preponderance is either the result of cellphone use protecting against malignant tumors, a study flaw, or a chance finding that 13 odds ratios would all be less than 1.0.
"Regular" Cellphone Use you may have noted that I have placed quotes around "regular" use. This is because all of the Interphone studies use a ridiculously low use as the definition of "regular" use. The definition is, "Regular use" defined as use of a mobile phone on average once per week or more, during 6 months or more.
It is important to place all of the cellphone studies in the context of a study of the risk of lung cancer from smoking.
Would a study of smokers who smoked on average once per week or more during 6 months or more, find a risk of lung cancer? Expanding this concept to smokers who had smoked once per week or more for 10 years or more, where there was only 1 smoker, would a risk of lung cancer be found?
Regards to all,
Lloyd
In a message dated 7/21/2006 10:24:04 AM Pacific Daylight Time, mlerner108 writes:
ATF:
A case-control study in Denmark and Sweden finds no association between parotid gland tumors and the use of mobile phones. The study matched 60 cases of malignant parotid gland tumors and 112 cases of benign pleomorphic adenomas with appropriate controls. They found no association, regardless of duration of mobile phone use, including use for more than 10 years' duration. American Journal of Epidemiology.
[cheemf] Negative study on parotid gland tumors and cell phones From: Louis Slesin
Date: Fri, 21 Jul 2006 20:11:50 +0100
I have taken a look at this study and I am bothered by the fact that the >10 year use finding of no effect is included in the abstract of the paper (which will appear in a future issue of the American Journal of Epidemiology).
The data do not support any conclusion concerning long-term risks.
For instance, if you look at malignant parotid gland tumors, the number of cases that used a mobile phone for ten or more years ipsilaterally (that is, phone use was on the same side of the head as the tumor) was only one. There were no cases at all for contralateral use.
For benign tumors, the risk is actually elevated for ipsilateral use... but here again the number of cases, though somewhat larger, is still small. For contralateral use, there was only one benign tumor case.
To its credit, the research team concludes that it is still too early to say much about long term users. But that does not explain why the misleading "all clear" statement about long-term use is in the abstract. After all, many, many more people have access to the abstract (PubMed etc.) than will ever get a copy of the paper.
Remember that in 2004 the Swedish members of this same team reported an increased risk of acoustic neuroma for ipsilateral use of a mobile phone for >10 years. See:
http://www.epidem.com/pt/re/epidemiology/abstract.00001648-200411000-00003.htm
Best,
Louis Slesin
Microwave News
Date: Fri, 21 Jul 2006 10:23:36 -0700
From: Michael Lerner
Subject: [cheemf] Negative study on parotid gland tumors and cell phones
ATF:
A case-control study in Denmark and Sweden finds no association between parotid gland tumors and the use of mobile phones. The study matched 60 cases of malignant parotid gland tumors and 112 cases of benign pleomorphic adenomas with appropriate controls. They found no association, regardless of duration of mobile phone use, including use for more than 10 years' duration. American Journal of Epidemiology.
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Mobile Phone Use and Risk of Parotid Gland Tumor
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16818464&dopt=Abstract
Schüz
http://omega.twoday.net/search?q=Sch%C3%BCz
