Thursday, February 1, 2024

Cell Phone Use and Salivary Gland Tumor Risk

Since the year 2000, the U.S. has experienced significant increases in the age-adjusted incidence rates of salivary gland cancer along with three other head and neck tumors associated with cell phone use

The age-adjusted incidence rate of salivary gland cancer significantly increased overall in the U.S. by 0.6% per year from 2000 to 2019The increase in age-adjusted incidence rates for this tumor is likely attributable to the chronic effects of mobile phone use in addition to other factors including improvements in screening.

Whereas the size of the population in the U.S. increased 16% between 2000 and 2019, the number of cases of salivary gland cancer reported in the National Cancer Institute's SEER 22 registry increased by 52%.

The tumor incidence rate data are from the SEER 22 Registry which covers 48% of the total U.S. population. The data were age-adjusted to the population in the year 2000 so observed differences over time are not affected by changes in the age composition of the population.

Reference: SEER*Explorer: An interactive website for SEER cancer statistics [Internet]. Surveillance Research Program, National Cancer Institute; 2023 Apr 19. [updated: 2023 Nov 16; cited 2024 Jan 9]. Available from: Data source(s): SEER Incidence Data, November 2022 Submission (1975-2020), SEER 22 registries.  


Does cell phone use increase the chances of parotid gland tumor development?
A systematic review and meta-analysis

de Siqueira EC, de Souza FTA, Gomez RS, Gomes CC, de Souza RP. Does cell phone use increase the chances of parotid gland tumor development? A systematic review and meta-analysis. J Oral Pathol Med. 2017 Aug;46(7):480-483. doi: 10.1111/jop.12531.


BACKGROUND: Prior epidemiological studies had examined the association between cell phone use and the development of tumors in the parotid glands. However there is no consensus about the question of whether cell phone use is associated with increased risk of tumors in the parotid glands. We performed a meta-analysis to evaluate the existing literature about the mean question and to determine their statistical significance.

METHODS: Primary association studies. Papers that associated cell phone use and parotid gland tumors development were included, with no restrictions regarding publication date, language and place of publication. Systematic literature search using PubMed, Scielo and Embase followed by meta-analysis.

RESULTS AND CONCLUSION: Initial screening included 37 articles and three were included in meta-analysis. Using three independent samples including 5087 subjects from retrospective case-control studies, cell phone use seems to be associated with greater odds (1.28, 95%- confidence interval 1.09 - 1.51) to develop salivary gland tumor. Results should be read with caution due to the limited number of studies available and their retrospective design.

Salivary gland tumors are relatively rare, accounting for 2-5% of all head and neck tumors, being the parotids the most affected salivary gland (6).

We further evaluated the levels of inflammatory cytokines in the saliva produced by the parotids according to self-reported exposure to cell phone, reporting an increase in pro-inflammatory and a decrease of anti-inflammatory cytokine levels in the sample evaluated, suggesting a pro-inflammatory effect of cell phones (8).

Cell phone use was associated with greater odds (increase of 28%) of presence of tumor in the parotid glands (O.R. 1.28 95% C.I. [1.09–1.51] p = 0.0025) (Figure 2).

Primary association studies have reported discordant results (3, 5, 10, 12, 14, 15). Possible explanations for conflicting results are differences in study design, genetic background of sampled populations or clinical-epidemiological sample structure. It is important to note that discordant results do not mean that some are incorrect. Tumor manifestation is clearly a multifactorial process whose risk factors are several. Most of the studies have not assessed other risk factors when estimating existence of association.

This is the first systematic review followed by a meta-analysis to evaluate that association. Here, we report usage of cell phone increase, on average, 28% the odds of presenting parotid glands tumors.

Our results need to be read and interpreted with caution due to important limitations that need to be addressed. Although the number of subjects compiled is reasonably large, the number of independent samples is small (n = 3) and results are clearly driven by two of three studies.


Taken together, our results provide evidence of association between cell phone use and parotid tumor although their association presents mild effect.


Histological and histochemical study of the protective role of rosemary extract against harmful effect of cell phone electromagnetic radiation on the parotid glands

Fatma M. Ghoneim, Eetmad A. Arafat. Histological and histochemical study of the protective role of rosemary extract against harmful effect of cell phone electromagnetic radiation on the parotid glands. Acta Histochemica, 118(5):478-485. June 2016.


Electromagnetic fields (EMFs) are a class of non-ionizing radiation (NIR) that is emitted from mobile phone. It may have hazardous effects on parotid glands. So, we aimed to investigate the histological and histochemical changes of the parotid glands of rats exposed to mobile phone and study the possible protective role of rosemary against its harmful effect. Forty adult male albino rats were used in this study. They were classified into 4 equal groups. Group I (control), group II (control receiving rosemary), group III (mobile phone exposed group) and group IV (mobile exposed, rosemary treated group). Parotid glands were dissected out for histological and histochemical study. Moreover, measurement of oxidative stress markers; malondialdehyde (MDA) and total antioxidant capacity (TAC) was done. The results of this study revealed that rosemary has protective effect through improving the histological and histochemical picture of the parotid gland in addition of its antioxidant effect. It could be concluded from the current study, that exposure of parotid gland of rat models to electromagnetic radiation of mobile phone resulted in structural changes at the level of light and electron microscopic examination which could be explained by oxidative stress effect of mobile phone. Rosemary could play a protective role against this harmful effect through its antioxidant activity.


From this study, it could be concluded that exposure of rat models to non-ionizing radiation emitted from mobile phone has hazardous effects on the histology and histochemistry of their parotid glands. Administration of rosemary extract which is a natural antioxidant resulted in a significant improvement. Unfortunately these preliminary results cannot be further extrapolated to humans. Therefore, we should adjust our use for mobile.

Also see: