The authors of COSMOS mobile phone-brain tumor study (Feychting et al., 2024a) failed to address numerous issues in their response
(Feychting et al., 2024b)
to the ICBE-EMF letter
(Moskowitz et al., 2024)
critiquing their study. ICBE-EMF stands by its
call for a retraction of the study's conclusions and demands that the
data set be made available to independent investigators who have no
industry ties.
Mads Rohde (MR), a senior advisor at the Cancer Registry of Norway, input the text from the ICBE-EMF letter into ChatGPT followed by the response to the letter. Then MR submitted the following queries to ChatGPT:
MR:
so u see the first was a critique and the next was a reply?
ChatGPT: "Yes, I see that the first document was a critique of the COSMOS study on mobile phone use and brain tumor risk, pointing out several methodological flaws and issues with exposure and outcome assessment, latency periods, statistical power, and potential funding bias. The second document was a reply from the authors of the COSMOS study, addressing the criticisms, defending their methodology, explaining their exposure assessment and outcome ascertainment, and emphasizing the independence and rigor of their research process."
MR:
ok, tell me what the response did not adequately address (which limitations that still apply even if we take their reply for being true).
ChatGPT: "Here are the limitations that the response from the COSMOS study authors did not adequately address, even if we take their reply at face value:Exposure Assessment Limitations:
- Lack of Updated Exposure Information: The reply acknowledges that the study did not update exposure information during the follow-up period (median 7.12 years), which is crucial as mobile phone technology and usage patterns evolved significantly during this time.
- Variability in RF-EMF Exposure: The reply did not adequately address the substantial variability in RF-EMF exposure due to different cellular technologies and signal strengths. While they mention that newer technologies emit lower levels of RF-EMF, the exposure from earlier technologies was not comprehensively accounted for.
Confounding Factors and Other RF-EMF Sources:
- Other RF-EMF Sources: The response did not fully address the critique that the study did not control for other sources of RF-EMF exposure such as cordless phones, Wi-Fi routers, and cell towers.
- Unexposed Group: The lack of a completely unexposed group remains a limitation. The authors argue that non-users would be an unsuitable comparison group due to confounding factors, but this does not mitigate the critique that without an unexposed group, the ability to detect risk differences is compromised.
Outcome Assessment Issues:
- Under-Reporting of Brain Tumors: While the authors refuted the claim of under-reporting based on administrative changes, the potential under-reporting in cancer registries remains a concern, especially for benign tumors like meningioma. The response did not convincingly dismiss the possibility of under-reporting affecting the study's results.
Statistical Power:
- Insufficient Number of Cases: The response acknowledges limited statistical power, especially for acoustic neuroma and meningioma. Despite their defense, the critique that the study had fewer cases than expected and thus limited power to detect significant associations stands valid.
Latency Periods:
- Insufficient Long-Term Data: The response did not adequately address the critique about insufficient long-term follow-up data. For cancers with long latency periods, the study's follow-up duration may not be sufficient to detect potential risks associated with long-term mobile phone use.
Funding and Potential Bias:
- Industry Funding Influence: The reply defends the independence of the study despite industry funding. However, the critique about potential funding bias due to partial industry funding and its influence on research outcomes remains a point of concern that was not fully mitigated by the authors' response.
In summary, while the COSMOS study authors addressed many points raised in the critique, significant limitations regarding exposure assessment, confounding factors, outcome assessment, statistical power, latency periods, and potential funding bias still apply and were not completely resolved by their reply."
References
Feychting M, Schüz J, Toledano MB, Vermeulen R, Auvinen A, Poulsen AH, Deltour I, Smith RB, Heller J, Kromhout H, Huss A, Johansen C, Tettamanti G, Elliott P.
Mobile phone use and brain tumour risk – COSMOS, a prospective cohort
study. Environment International, Volume 185, 2024a, 108552, https://doi.org/10.1016/j. envint.2024.108552. (https://www.sciencedirect. com/science/article/pii/ S0160412024001387).
Feychting M, Schüz J, Toledano MB, Vermeulen R, Auvinen A, Poulsen AH, Deltour I, Smith RB, Heller J, Kromhout H, Huss A, Johansen C, Tettamanti G, Elliott P. Response to the letter to the editor regarding “Mobile phone use and brain tumour risk − COSMOS, a prospective cohort study”. Environment International, Volume 189, 2024b, 108808, https://doi.org/10.1016/j. envint.2024.108808. (https://www.sciencedirect. com/science/article/pii/ S0160412024003945).
Moskowitz JM,
Frank JW, Melnick RL, Hardell L, Belyaev I, Héroux P, Kelley E, Lai H,
Maisch D, Mallery-Blythe E, Philips A. COSMOS. A
methodologically-flawed cohort study of the health effects from exposure
to radiofrequency radiation from mobile phone use. Environment
International, Volume 190, 2024, 108807, https://doi.org/10.1016/j. envint.2024.108807. (https://www.sciencedirect. com/science/article/pii/ S0160412024003933).--
Exposure Assessment Limitations:
- Lack of Updated Exposure Information: The reply acknowledges that the study did not update exposure information during the follow-up period (median 7.12 years), which is crucial as mobile phone technology and usage patterns evolved significantly during this time.
- Variability in RF-EMF Exposure: The reply did not adequately address the substantial variability in RF-EMF exposure due to different cellular technologies and signal strengths. While they mention that newer technologies emit lower levels of RF-EMF, the exposure from earlier technologies was not comprehensively accounted for.
Confounding Factors and Other RF-EMF Sources:
- Other RF-EMF Sources: The response did not fully address the critique that the study did not control for other sources of RF-EMF exposure such as cordless phones, Wi-Fi routers, and cell towers.
- Unexposed Group: The lack of a completely unexposed group remains a limitation. The authors argue that non-users would be an unsuitable comparison group due to confounding factors, but this does not mitigate the critique that without an unexposed group, the ability to detect risk differences is compromised.
Outcome Assessment Issues:
- Under-Reporting of Brain Tumors: While the authors refuted the claim of under-reporting based on administrative changes, the potential under-reporting in cancer registries remains a concern, especially for benign tumors like meningioma. The response did not convincingly dismiss the possibility of under-reporting affecting the study's results.
Statistical Power:
- Insufficient Number of Cases: The response acknowledges limited statistical power, especially for acoustic neuroma and meningioma. Despite their defense, the critique that the study had fewer cases than expected and thus limited power to detect significant associations stands valid.
Latency Periods:
- Insufficient Long-Term Data: The response did not adequately address the critique about insufficient long-term follow-up data. For cancers with long latency periods, the study's follow-up duration may not be sufficient to detect potential risks associated with long-term mobile phone use.
Funding and Potential Bias:
- Industry Funding Influence: The reply defends the independence of the study despite industry funding. However, the critique about potential funding bias due to partial industry funding and its influence on research outcomes remains a point of concern that was not fully mitigated by the authors' response.
In summary, while the COSMOS study authors addressed many points raised in the critique, significant limitations regarding exposure assessment, confounding factors, outcome assessment, statistical power, latency periods, and potential funding bias still apply and were not completely resolved by their reply."
--
June 26, 2024
ICBE-EMF exposes major flaws in COSMOS cell phone brain tumor risk study in journal letter published today
COSMOS (“Cohort Study on Mobile Phone Use and Health”) is a 20-30-year cohort study investigating the possible health effects of long-term use of mobile phones and other wireless technologies. The study enrolled over 290,000 mobile phone users from six European countries (Denmark, Finland, France, Sweden, the Netherlands, and the United Kingdom).
The ICBE-EMF is made up of a multidisciplinary consortium of scientists, doctors and related professionals who are involved with research related to the biological and health effects of electromagnetic frequencies up to and including 300 GHz. The organization makes recommendations that include and go beyond establishing numerical exposure guidelines based on the best peer-reviewed scientific research publications.
1. Problems with exposure assessment
... Misclassification of RFR exposure was substantial because the amount of exposure from a mobile phone varies by up to four orders of magnitude depending on the cellular network technology and the strength of the signal from the cell tower (Wall et al., 2019). COSMOS did not account for this variability. The study also did not control for other sources of RFR exposure, including cordless phones, personal wireless devices, Wi-Fi routers, and cell towers....
Since almost everyone in this cohort study regularly used mobile phones at baseline (including two-thirds who used mobile phones for 10 or more years) and many were exposed to others sources of RFR (e.g., cordless DECT phones, cell towers, Wi-Fi), there was no unexposed group. That the authors chose to use the bottom 50 % of the mobile phone use distribution as the reference group instead of a more extreme percentile cutoff (e.g., the bottom decile of mobile phone use) does not seem defensible....
2. Problems with outcome assessment
The incidence of brain tumors may be under-reported in the five national cancer registries that this study relied upon to assess outcomes....
3. Latency, type and location of tumors
Most human cancers have long latencies, requiring many years to decades after exposure to carcinogens before clinical presentation and diagnosis (Armenian, 1987, Nadler and Zurbenko, 2022). Accordingly, it is critical in cohort studies like COSMOS to stratify on the total length of time between initiation of any given level of exposure – in this case to RFR – and the date of cancer diagnosis, especially since so many members of the COSMOS cohort already had many years of substantial RFR exposure when recruited....
This interim study by Feychting et al. (2024) does not have a sufficient number of subjects followed for more than a decade after RFR exposure began to rule out elevated risks of these two tumors after the most relevant latent periods for carcinogenesis....
4. Statistical issues
Although the authors acknowledged that “Statistical power was limited for meningioma and acoustic neuroma,” we contend that glioma with only 149 incident cases in this study of 1.836 million person years also had limited statistical power. The confidence intervals for the hazard ratios were large. Moreover, the power analysis in the COSMOS design paper (Table 2, Schüz et al., 2011) assumed an annual incidence rate of 15 per 100,000 for brain tumors, whereas the glioma annual incidence rate in the current study was 8.11 per 100,000. Thus, no analysis of tumor risk in this paper had adequate statistical power.
We question whether the study adequately addressed the heterogeneity among countries....
The Data Availability section of the paper states, “The data that has been used is confidential.” If the authors are using this as the reason not to share their data, then the results cannot be confirmed by independent investigators. Since these data have potentially important policy implications, the data set must be accessible to other researchers....
5. Industry research funding
Funding bias is well-recognized in biomedical research (Bekelman et al., 2003). Industry-funded studies were less likely to report statistically significant health-related effects associated with mobile phone use than non-industry funded studies (Huss et al., 2007, Moskowitz et al., 2020). For example, a review of experimental studies concluded, “industry-sponsored studies were least likely to report results suggesting effects… The source of funding and conflicts of interest are important to consider in this area of research (van Nierop et al., 2010).
COSMOS was partially funded by the telecommunications industry in three countries, Finland, Sweden, and the United Kingdom (Feychting et al., 2024)....
Given the serious methodologic problems with this interim COSMOS paper discussed above, we recommend that the authors retract their conclusion: “Our findings to date, together with other available scientific evidence, suggest that mobile phone use is not associated with increased risk of developing these tumours.”.
To support this assertion the authors relied on evidence from three cohort studies (Feychting et al., 2024, Schüz et al., 2006, Schüz, 2022) with weak methodology (Ahlbom et al., 2007, Birnbaum et al., 2022, Moskowitz, 2022, Söderqvist et al., 2012). For example, IARC concluded, “reliance on subscription to a mobile phone provider, as a surrogate for mobile phone use, could have resulted in considerable misclassification in exposure assessment” (Baan et al., 2011). Schüz et al. (2022) did not provide data on cumulative phone use. To support their “no association” conclusion, the COSMOS authors also cited time-trend studies; yet, these studies reported significant increases in brain tumor incidence in age-specific subgroups (e.g., de Vocht, 2021, Deltour et al., 2022, Elwood et al., 2022: Ostrom et al., 2022). Finally, the COSMOS authors cited a review of case-control studies that dismissed the results of the cumulative call time analysis by relegating it to the appendix (i.e., Supplemental Figure 2, Röösli et al., 2019).
In contrast to Röösli et al., 2019, Choi et al., 2020 systematic review and meta-analysis of 46 case-control studies”found significant evidence linking cellular phone use to increased tumor risk, especially among cell phone users with cumulative cell phone use of 1000 or more hours in their lifetime,” and called for high quality, prospective cohort studies to confirm the results of the case-control research.