Exposure to secondhand smoke can increase risk of oral cancer

People who are exposed to secondhand tobacco smoke could have a 51% higher risk of developing oral cancer, research suggests.

This is according to a new study published in Tobacco Control.

It shows that inhaling secondhand smoke counts as a significant risk factor when it comes to developing oral cancer.

Oral cancers – which includes lip, oropharynx and oral cavity cancers – account for more than 440,000 new cases of cancer, as well as 228,389 deaths each year.

Smoke exposure

Significant risk factors for these include smoking tobacco, use of smokeless tobacco, betel quid chewing and consumption of alcohol.

However, it is not just active smokers who are impacted. Data collected from 192 countries reveals 33% of male non-smokers and 35% of female non-smokers were involuntarily exposed to secondhand smoke. This figure stands at 40% for children.

As a result, the team – drawn from Spain, Portugal, the UK and the US – investigated whether secondhand smoke exposure and oral cancers are linked.

And results show that those inhaling secondhand smoke had a 51% higher risk of developing oral cancer.

Additionally, the exposure duration of more than 10 or 15 years also has an influence. For example, it increased the risk of oral cancer to more than twice compared with non-exposed individuals.

Harmful effects

‘This systematic review and meta-analysis supports a causal association between secondhand smoke exposure and oral cancer,’ said the authors.

‘Moreover, the analyses of exposure response – including by duration of exposure (more than 10 or 15 years) to secondhand smoke – further supports causal inference.

‘The identification of the harmful effects of secondhand smoke exposure provides guidance to public health professionals, researchers, and also policymakers.’

The research team analysed five existing relevant studies involving 6,977 people, of whom 3,452 were exposed to secondhand smoke. These were carried out in Asia, Europe, North America and Latin America.