GENEVA (Reuters) - The World Health Organization released new findings on Friday about an "alarming" lack of awareness about alcohol's link to cancer across Europe and called for clear and prominent tobacco-style warnings in the region with the world's heaviest drinkers.

Alcohol causes 800,000 deaths across Europe each year but just a fraction of the population is aware of the risks, the WHO's Europe office said in a statement, based on a new survey. It found that just 15% of respondents knew that alcohol causes breast cancer and 39% were aware of its link to colon cancer, the statement said.

"Despite cancer being the leading cause of alcohol-attributable deaths in the European Union (EU), public awareness of the link between alcohol and cancer remains alarmingly low," the WHO said.

The global health agency has repeatedly warned that alcohol causes cancer and has backed clear labelling but has never before been as prescriptive in its call for new government regulations.

Relying on self-regulation, as the industry would prefer, brings the risk that alcohol producers use "inconspicuous placement and ambiguous messaging" or use QR codes which tend to be ignored by shoppers, the WHO said.

Instead, alcoholic drinks should display "clear and prominent health warnings" in written format which could be combined with pictures "to maximise reach and empower consumers with clear, accurate information to make informed choices about their health," it said.

Currently, just three out of 27 EU countries have such labels, the WHO said. Earlier this year, the U.S. Surgeon General also called for warnings of cancer risks on drink labels.

(Reporting by Emma Farge; Editing by Sharon Singleton)