Cancers of the brain and CNS: global patterns and trends in incidence

Abstract

Important regional variations in brain and CNS cancers exist, and given an increasing burden and risk worldwide, there is a need for further etiological research that focuses on the elucidation of environmental risk. The trends are sufficiently complex and diffuse, however, to warrant a cautious approach to interpretation.

Analyses of temporal and spatial patterns of glioblastoma multiforme and other brain cancer subtypes in relation to mobile phones using synthetic counterfactuals

“…A previous study based on English cancer incidence data and a novel causal inference framework based on synthetic counterfactuals indicated that the observed increase in malignant neoplasms in the temporal lobe between 1985-2014 was in agreement with mobile phone use as an important causal factor, but that for GBM, despite its incidence increasing over time as well, this did not deviate from expected, counterfactual, trends , de Vocht, 2017). Similar trends have been observed elsewhere (Ho et al, 2014, Kim et al, 2015, Ostrom et al, 2014, Zada et al, 2012, and improvements in diagnostics techniques, especially in the elderly, is generally considered the main explanation for the observed increase in incidence, while genetic risk factors and ionizing radiation exposure are known to increase the risk and allergic conditions appear to decrease it (Miranda-Filho et al, 2017) . A variety of other potential contributing factors have also been hypothesized to additionally explain these patterns, including hormonal contraceptives, hormone replacement therapy, statins, certain infections, a variety of occupational exposures, vitamin D, alcohol, height, BMI, as well as non-ionizing radiation including RF from mobile phones (Kim et al, 2015, Miranda-Filho et al, 2017, Philips et al, 2018.…”

“…Similar trends have been observed elsewhere (Ho et al, 2014, Kim et al, 2015, Ostrom et al, 2014, Zada et al, 2012, and improvements in diagnostics techniques, especially in the elderly, is generally considered the main explanation for the observed increase in incidence, while genetic risk factors and ionizing radiation exposure are known to increase the risk and allergic conditions appear to decrease it (Miranda-Filho et al, 2017) . A variety of other potential contributing factors have also been hypothesized to additionally explain these patterns, including hormonal contraceptives, hormone replacement therapy, statins, certain infections, a variety of occupational exposures, vitamin D, alcohol, height, BMI, as well as non-ionizing radiation including RF from mobile phones (Kim et al, 2015, Miranda-Filho et al, 2017, Philips et al, 2018. This paper further expands on previous analyses and utilises the strengths of the Bayesian causal inference work using synthetic counterfactuals to explore the likelihood of mobile phone use as the important putative factor explaining the increases in the incidence of GBM in different anatomic brain regions and for specific malignant (other than GBM) and benign (acoustic neuroma and meningioma) subtypes in the temporal lobe specifically (based on the results from the previous study (de Vocht, 2016)).…”

“…If exposure to radiofrequency radiation from mobile phones is not the driving factor behind the observed excesses in primarily GBM rates, it is interesting to speculate what this other factor could be. Several candidates have been mentioned (Miranda-Filho et al, 2017), including some of environmental origin (Philips et al, 2018), but alternatively it has been suggested that the observed increase in the incidence of GBM is the result of improved diagnosis techniques, especially at older age (Kim et al, 2015, Zada et al, 2012, Davis et al, 1990, Greig et al, 1990, and improvements in classifications of gliomas, including the increased use of molecular markers (Ludwig and Kornblum, 2017) . The current analyses seem to support the latter interpretation, at least in so far as a main driving factor is considered, and this is further strengthened by the patterns observed for newly diagnosed cases of GBM in overlapping lesions or of an unspecified nature.…”

“…However, the region-specific analyses in this study were suggestive of comparable patterns compared to the counterfactuals in the occipital and cerebral lobes as well, suggesting effects may be less strong, but not exclusive to the aforementioned anatomic regions. Most likely the observed trends are the result of a combination of different factors, environmental and/or other (Miranda-Filho et al, 2017, Ostrom et al, 2014, and which may include mobile phone usage. Regardless, although this study (nor any of the previous ones) can unambiguously in-or exclude mobile phone usage as a contributing causal factor, data are broadly in agreement that the contribution of mobile phone usage in causing GBM or other types of brain cancer, if any, is likely to be small.…”

Simulation of the incidence of malignant brain tumors in birth cohorts that started using mobile phones when they first became popular in Japan

“…A decreasing trend in the incidence of malignant brain tumors was reported in both males and females between 1993 and 2007 in Japan [Miranda‐Filho et al, ]. In that analysis, the age‐adjusted incidence of subjects aged 15 years old and over was shown.…”