Interpretation of Timetrends (1996-2017) of the Incidence of Selected Cancers in England in Relation to Mobile Phone Use as a Possible Risk Factor

Abstract

Interpretation of Timetrends (1996-2017) of the Incidence of Selected Cancers in England in Relation to Mobile Phone Use as a Possible Risk Factor Frank de Vocht. Interpretation of Timetrends (1996-2017) of the Incidence of Selected Cancers in England in Relation to Mobile Phone Use as a Possible Risk Factor. Bioelectromagnetics. 2021 Oct 11. doi: 10.1002/bem.22375. Abstract Radiofrequency (RF) radiation from mobile phones has been classified as possibly carcinogenic to humans (2b) by IARC. However, to date, the discussion on whether mobile phone use is a cancer risk factor has not been solved. In this context of continuing uncertainty, it is important to continue to monitor cancer incidence trends. Annual incidence rates and directly age-standardized rates of selected cancers by sex and 5-year age groups for 1996 to 2017 for England were obtained from the UK Office for National Statistics. Interpretation in light of mobile phone use as a contributing risk factor was conducted for cancers of the brain, parotid gland, thyroid, and colorectal cancer, which have all been hypothesized to be associated with RF exposure. Brain and parotid gland cancers were updated by an additional 10 years following a previous publication, and continue to provide little evidence of an association with mobile phone use. Although mobile phone use as a potential risk factor contributing to increased incidence of colorectal or thyroid cancer could not be excluded based on these ecological data, it is implausible that it is an important risk factor for either. In the absence of clarity from epidemiological studies, it remains important to continue to monitor trends. However, for the time being, and in agreement with data from other countries, there is little evidence of an association between mobile phone use and brain or parotid gland cancer, while the hypotheses of associations with thyroid or colorectal cancer are similarly weak. pubmed.ncbi.nlm.nih.gov My comments: This paper provides a biased interpretation of data from a weak observational study that employs ecological, time series data. Given the limitations of cancer registry data, interpretation of cancer incidence trends is fraught with problems. Although the results of this observational study are not clear-cut, the overall results suggest that standardized cancer incidence rates in England for all four cancers under investigation increased over time: “Although the DAS rates suggest an increase of 30% in the incidence rates of brain cancers in women and 34% in men from 1996 to 2017….” “A steady increase (p<0.001) from 0.4 to 0.6 incident cases per 100,000 women and 0.7 to 0.8 for men, respectively, over the 1999-2017 time period was observed for incidence of cancer of the parotid gland; mainly in DAS rates following the use of the revised ESP (Figure 2).” “Cancer of the thyroid gland has increased steadily over time (p<0.001), especially in women where the DAS rate has more than tripled from 1996 to 2017 from 2.7 incident cases to 8.5 per 100,000 women but also in men (from 1.2 to 3.6 incident cases per 100,000 men), with little differences between population rates and DAS rates (Figure 3).” “The incidence rates of colorectal cancer in England have been stable for women (+3% from 1999 to 2017; p<0.001) and slightly increasing for men (+15% from 1999 to 2017; p<0.0.01) (Figure 4).…In younger age groups clear increase in incidence can be observed, especially in the age groups 25-34 year olds describing annual increases of 7% in both sexes (p<0.001), with some indication of plateauing of this pattern in those of 29 years or younger.” The above results could have been interpreted as supportive of the association with increases in mobile phone use over time in England due to the considerable lag between exposure to a risk factor and diagnosis of solid tumors. Furthermore, the case-control research suggests the increased cancer risk is a function of heavy mobile phone use (e.g., 17 minutes per day over a ten-year period for risk of glioma [Choi et al., 2020]) and perhaps also genetic susceptibility (for thyroid cancer risk [Luo et al., 2018, 2020]) so not everyone would be affected. Analyzing time trend data may be a fruitless endeavor when there are multiple risk factors for the tumors under investigation because some carcinogens may be increasing over time while others are decreasing. It is impossible to make causal attributions with time series designs when there is a considerable lag between an exposure (e.g., mobile phone use) and an outcome (e.g., cancer). Similarly, it is problematic to rule out a risk factor with such a weak research design. The results clearly do not warrant the following assertions made by this paper: “Although mobile phone use as a potential risk factor contributing to increased incidence of colorectal or thyroid cancer could not be excluded based on these ecological data, it is implausible that it is an important risk factor for either.” “…there is little evidence of a causal relation of mobile phone use with brain or parotid gland cancer, while the hypotheses of associations with thyroid or colorectal cancer is similarly weak.” Although the strongest epidemiologic evidence for increased cancer risk associated with mobile phone use is for glioma, a subtype of brain cancer (IARC Working Group, 2013), the paper did not cite Philips et al. (2018). Yet the Philips study examined brain cancer incidence data for England from 1995-2015 to calculate incidence rates (ASR) per 100,000 person-years, age-standardized to the European Standard Population (ESP–2013). Philips et al. found “a sustained and highly statistically significant ASR rise in glioblastoma multiforme (GBM) [a subtype of glioma] across all ages. The ASR for GBM more than doubled from 2.4 to 5.0, with annual case numbers rising from 983 to 2531. Overall, this rise is mostly hidden in the overall data by a reduced incidence of lower grade tumours.” Thus, it should come as no surprise that the current paper failed to find much of an increase in overall brain cancer incidence in England for almost the same time period.

AI evidence extraction

Main findings

Using cancer incidence data for England (1996-2017), the author reports that brain and parotid gland cancer trends provide little evidence of an association with mobile phone use. For thyroid and colorectal cancer, the author states that a contribution from mobile phone use could not be excluded based on ecological data but argues it is implausible that mobile phone use is an important risk factor, and concludes the hypothesized associations are weak.

Outcomes measured

• Brain cancer incidence trends
• Parotid gland cancer incidence trends
• Thyroid cancer incidence trends
• Colorectal cancer incidence trends

Limitations

• Ecological/time-trend design limits causal inference and cannot link individual mobile phone use to cancer outcomes
• Potential confounding by other time-varying factors affecting cancer incidence is not addressed in the abstract
• Latency and diagnostic/registration changes over time may influence observed incidence trends
• Exposure is not directly measured; mobile phone use is considered indirectly as a population-level risk factor

Suggested hubs

• cell-phones (0.95)
  Study interprets cancer incidence trends in relation to mobile phone use as an RF exposure source.

{
    "publication_year": null,
    "study_type": "ecological",
    "exposure": {
        "band": "RF",
        "source": "mobile phone",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "1996-2017 (incidence trends evaluated over this period)"
    },
    "population": "England population (cancer incidence by sex and 5-year age groups)",
    "sample_size": null,
    "outcomes": [
        "Brain cancer incidence trends",
        "Parotid gland cancer incidence trends",
        "Thyroid cancer incidence trends",
        "Colorectal cancer incidence trends"
    ],
    "main_findings": "Using cancer incidence data for England (1996-2017), the author reports that brain and parotid gland cancer trends provide little evidence of an association with mobile phone use. For thyroid and colorectal cancer, the author states that a contribution from mobile phone use could not be excluded based on ecological data but argues it is implausible that mobile phone use is an important risk factor, and concludes the hypothesized associations are weak.",
    "effect_direction": "no_effect",
    "limitations": [
        "Ecological/time-trend design limits causal inference and cannot link individual mobile phone use to cancer outcomes",
        "Potential confounding by other time-varying factors affecting cancer incidence is not addressed in the abstract",
        "Latency and diagnostic/registration changes over time may influence observed incidence trends",
        "Exposure is not directly measured; mobile phone use is considered indirectly as a population-level risk factor"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "stance": "reassurance",
    "stance_confidence": 0.7199999999999999733546474089962430298328399658203125,
    "summary": "This ecological time-trend analysis used England cancer incidence data from 1996 to 2017 to interpret trends in relation to mobile phone use as a possible RF exposure risk factor. The author reports little evidence of an association for brain and parotid gland cancers. For thyroid and colorectal cancers, the author notes an association cannot be excluded from ecological data but considers mobile phone use an implausible major contributor and characterizes the hypotheses as weak.",
    "key_points": [
        "RF radiation from mobile phones is noted as IARC Group 2B (possibly carcinogenic) in the background.",
        "Cancer incidence rates for England (1996-2017) were examined by sex and 5-year age groups using Office for National Statistics data.",
        "The paper interprets brain and parotid gland cancer trends as providing little evidence of association with mobile phone use.",
        "For thyroid and colorectal cancer, the author states a contribution from mobile phone use cannot be excluded using ecological data.",
        "Despite that uncertainty, the author argues mobile phone use is unlikely to be an important risk factor for thyroid or colorectal cancer.",
        "The paper emphasizes continued monitoring of cancer incidence trends given ongoing uncertainty in the broader literature."
    ],
    "categories": [
        "Epidemiology",
        "Cancer",
        "Mobile Phones",
        "Radiofrequency (RF)"
    ],
    "tags": [
        "Cancer Incidence Trends",
        "Ecological Study",
        "Time Trends",
        "England",
        "Brain Cancer",
        "Parotid Gland Cancer",
        "Thyroid Cancer",
        "Colorectal Cancer",
        "Mobile Phone Use",
        "Radiofrequency Radiation",
        "Age-Standardized Rates"
    ],
    "keywords": [
        "IARC 2B",
        "radiofrequency",
        "mobile phones",
        "cancer incidence",
        "brain",
        "parotid gland",
        "thyroid",
        "colorectal",
        "England",
        "age-standardized"
    ],
    "suggested_hubs": [
        {
            "slug": "cell-phones",
            "weight": 0.9499999999999999555910790149937383830547332763671875,
            "reason": "Study interprets cancer incidence trends in relation to mobile phone use as an RF exposure source."
        }
    ],
    "social": {
        "tweet": "England cancer incidence trends (1996–2017) were interpreted in relation to mobile phone RF exposure. The author reports little evidence of association for brain or parotid gland cancers and considers hypothesized links with thyroid or colorectal cancer weak, while noting ecological data cannot exclude contributions.",
        "facebook": "A time-trend (ecological) analysis of England cancer incidence (1996–2017) considered whether mobile phone RF exposure could be a contributing risk factor. The author reports little evidence of association for brain and parotid gland cancers and argues potential links with thyroid or colorectal cancer are weak, while emphasizing continued monitoring.",
        "linkedin": "This ecological time-trend paper analyzes England cancer incidence data (1996–2017) and interprets trends in relation to mobile phone RF exposure. It reports little evidence of association for brain and parotid gland cancers and characterizes hypothesized associations with thyroid and colorectal cancer as weak, while noting that ecological data cannot fully exclude contributions and that ongoing monitoring remains important."
    }
}

Comments

Log in to comment.

No comments yet.