Altra meta-analisi su cancro alla testa

In questo recentissimo lavoro tre ricercatori hanno studiato lavori epidemiologici più recenti rispetto alla ultima meta-analisi del 2009, adottando criteri selettivi per considerare solo lavori qualificati e ben documentati.
24 studi sono stati presi in considerazione con 27.000 ca casi e 50.000 controlli.

Le conclusioni sono impressionanti:  
- c'è una relazione causale tra uso di cellulare per più di 10 anni e tumore intracraniale
- un uso sistematico per più i 1640 ore porta ad un incremento del rischio di 2,5 volte per il neuroma
- altra correlazione con la età di inizio utilizzo sistematico con i tumori : addirittura arrivano a dimostrare che cominciare ad utilizzare il cellulare prima dei 20 anni dà una probabilità 4 volte superiore di avere il glioma (un tipo di cancro)

Mobile phone use and risk for intracranial tumors and salivary gland tumors - A meta-analysis

Bortkiewicz A, Gadzicka E, Szymczak W. Mobile phone use and risk for intracranial tumors and salivary gland tumors - A meta-analysis. Int J Occup Med Environ Health. 2017 Feb 21;30(1):27-43. doi: 10.13075/ijomeh.1896.00802. Epub 2017 Feb 13.

Abstract

Results of epidemiological studies on the association between use of mobile phone and brain cancer are ambiguous, as well as the results of 5 meta-analysis studies published to date. Since the last meta-analysis (2009), new case-control studies have been published, which theoretically could affect the conclusions on this relationship. Therefore, we decided to perform a new meta-analysis. We conducted a systematic review of multiple electronic data bases for relevant publications. The inclusion criteria were: original papers, case-control studies, published till the end of March 2014, measures of association (point estimates as odds ratio and confidence interval of the effect measured), data on individual exposure. Twenty four studies (26 846 cases, 50 013 controls) were included into the meta-analysis. A significantly higher risk of an intracranial tumor (all types) was noted for the period of mobile phone use over 10 years (odds ratio (OR) = 1.324, 95% confidence interval (CI): 1.028-1.704), and for the ipsilateral location (OR = 1.249, 95% CI: 1.022-1.526). The results support the hypothesis that long-term use of mobile phone increases risk of intracranial tumors, especially in the case of ipsilateral exposure. Further studies are needed to confirm this relationship.

Excerpts

The results obtained in the random effects model indicated that there was a significant relationship between mobile phone use for longer than 10 years and the risk of intracranial tumors (OR = 1.46, 95% CI: 1.07–1.98).

Because OR is significantly greater than 1 (OR = 1.25, 95% CI: 1.04–1.52), we can conclude that there is a significant relationship between the time from the first regular use of mobile phone of 10 years or more and the risk of intracranial tumors.

Since OR is greater than 1 (OR = 1.29, 95% CI: 1.06–1.57), there is a significant relationship between ipsilateral use of mobile phone and the risk of intracranial tumor.

We found a significant relationship between:
–– all intracranial tumors and all phone types; ipsilateral exposure;
–– all intracranial tumors and all phone types, when the time of mobile phone use was not shorter than 10 years;
–– all intracranial tumors and all phone types when the time from the first regular use of mobile phone was 10 years or more.

We are not able to compare our results with reference to different kinds of intracranial tumors (glioma, meningioma, acoustic neuroma) in relation to time of using mobile phones. A reliable analysis was not feasible because, in our opinion, the number of original works is too small.

Conclusions
Our results support the hypothesis that long-term (over 10 years) use of mobile phones increases the risk of intracranial tumors, especially in the case of ipsilateral exposure. The same conclusions are valid for the work by Davis et al. (2013) [45], who reviewed papers on the association between the use of wireless (mobile and cordless) phones and intracranial tumors. Those authors stress that the risk of tumors in people who have used the phone for periods longer than 10 years is significantly elevated. In people who had started using the phone on a regular basis before they were 20 years old, the risk of ipsilateral glioma was found to be fourfold higher. Hardell et al. (2013) [46] stress the significance of the “lifetime exposure dose.” For an exposure of ≥ 1640 h, the risk of ipsilateral acoustic neuroma is 2.55 (95% CI: 1.5–4.4). 

These results are in concordance with the conclusion of the expert panel for the International Agency for Research on Cancer (IARC), that cell phones are possibly carcinogenic (Group 2B) [47]. More research is needed to confirm that electromagnetic fields emitted by mobile phones are carcinogenic to humans.

Open Access Paper: http://bit.ly/2m8Amwt