Even light and moderate drinking - up to one drink a day for women and two drinks a day for men - could increase the risk of cancer, say researchers.
The work in the British Medical Journal looked at two large US studies involving more than 100,000 adults. The clearest link was for breast cancer.
Experts say the findings reinforce the health message that people should limit how much they drink and have some alcohol-free days.
There is no guaranteed safe level of drinking, but if you drink within the recommended daily limits, the risks of harming your health are low, they say.
The risks
Alcohol is linked to an increased risk of mouth, throat, gullet, bowel, liver and breast cancer
Smoking and drinking together further increases cancer risk
All types of alcohol increase cancer risk
The more you drink, the higher the risk
Cutting down on alcohol can reduce cancer risk