Drinking more than the equivalent of 12g of pure alcohol (125 ml wine or half a liter beer) can put women at risk to die of cancer. About double this quantity can put men at a similar risk. The amount of alcohol that puts you at risk depends on the weight and age of the drinker; the mentioned levels refer to women and men of average weight only.
An important number of cancer cases can be avoided if alcohol consumption is limited to less than a standard drink. Even more cancer cases would be prevented if drinkers reduced their alcohol intake to below recommended guidelines or stopped drinking alcohol at all.
The general message is: drink occasionally, but not regularly!