Risk of cancer: occupational or lifestyle choices?

Earlier this month The International Journal of Environmental Research and Public Health published a study titled “Variation in Nordic Work-Related Cancer Risks after Adjustment for Alcohol and Tobacco“. Study´s lead author Kristina Kjaerheim, from the Cancer Registry of Norway, explained how their study shed further light on alcohol as a cancer risk factor.

Lauri Beekmann: So first, could you shortly explain what were your main findings, especially in connection to alcohol´s role?

Kristina Kjaerheim: We investigated the risk of cancer at selected sites according to occupational affiliation after adjusting for consumption of alcohol and tobacco.
The cancer sites included were cancer of the tongue, mouth, pharynx, larynx, oesophagus, liver, colon, and rectum, all of which have an established association with alcohol drinking and tobacco smoking. Our study did not allow us to separate the effect of the two risk factors. Our main aim was to produce valid risk estimates for the mentioned cancer sites which could be attributed to other factors than alcohol and tobacco, i.e. occupational risk factors or possibly other factors related to social class or lifestyle. The study, however, showed that alcohol and tobacco contribute considerably to occupational variation in cancer risk in the Nordic countries.

Did your research change the view that we already have on alcohol as a risk factor for cancer?

Our results strongly support/confirm what previous research has shown, that alcohol and tobacco are main risk factors specifically for cancer of the tongue, mouth, pharynx, and larynx, contributes strongly to occupational variation in oesophagus and liver cancer risk, and has a weaker but measurable effect on colon and rectum cancer risk.

Could you bring an example from occupations where alcohol had a significant role?

Fourteen of the identified occupational categories could be categorised as high-risk occupations before adjustment for alcohol and tobacco were made. These groups were artists, journalists, sales agents, shop workers, drivers, painters, printers, packers, beverage workers, cooks and stewards, waiters, hairdressers, the combined group of other workers, and the group of economically inactive. Adjustment for alcohol and tobacco suggested that most of the elevated risk could be ascribed to alcohol and tobacco consumption.
For male waiters, for instance, the unadjusted risk of cancer of the tongue, mouth and pharynx was 4.4-6.1 times higher than in the general male population, while after adjustment risk was between equal or up to 1,3 times higher.

What do you see as possible practical implications of your research?

Besides giving leads to where to search for new occupational cancer hazards, the results should guide future preventive efforts to be designed and targeted specifically at the occupations where cancer risk was appreciably reduced by adjustment for alcohol and tobacco.