Time trend in incidence of malignant neoplasms of the central nervous system in relation to mobile phone use among young people in Japan

The aim of this study was to examine whether incidence of malignant neoplasms of the central nervous system from 1993 to 2010 has increased among young people in Japan, and whether the increase could be explained by increase in mobile phone use. Joinpoint regression analysis of incidence data was performed. Subsequently, the expected incidence rate was calculated assuming that the relative risk was 1.4 for those who used mobile phones more than 1640h cumulatively. Annual percent change was 3.9% (95% confidence interval [CI], 1.6-6.3) for men in their 20s from 1993 to 2010, 12.3% (95% CI, 3.3-22.1) for women in their 20s from 2002 to 2010, 2.7% (95% CI, 1.3-4.1) for men in their 30s from 1993 to 2010, and 3.0% (95% CI, 1.4-4.7) for women in their 30s from 1993 to 2010. Change in incidence rates from 1993 to 2010 was 0.92 per 100,000 people for men in their 20s, 0.83 for women in their 20s, 0.89 for men in their 30s, and 0.74 for women in their 30s. Change in expected incidence rates from 1993 to 2010 was 0.08 per 100,000 people for men in their 20s, 0.03 for women in their 20s, 0.15 for men in their 30s, and 0.05 for women in their 30s. Patterns in sex-, age-, and period-specific incidence increases are inconsistent with sex-, age-, and period-specific prevalence trends, suggesting the overall incidence increase cannot be explained by heavy mobile phone use. Bioelectromagnetics. 37:282-289, 2016. (c) 2016 Wiley Periodicals, Inc.