Over the years there have been suggestions that drinking large quantities of coffee could lead to developing certain types of cancer. Breast cancer, cancer of the bladder and cancer of the pancreas have all been mentioned in this connection.
Large studies, however, have failed to find any definite link between coffee drinking, even when the consumption has been heavy and any of these cancers, or any other type of cancer.
So from the point of view of cancer risk coffee drinking seems safe.

