Fifty years after the first U.S. Surgeon General's report in 1964 warned about the link between smoking and lung cancer, research continues to identify more diseases that are directly caused by smoking.
Now, liver and colorectal cancers have been added to the list of cancers for which there's sufficient data to infer smoking is not merely linked to but actually can cause the diseases, according to the newest Surgeon General's report released today (Jan 17).
Cigarette smoke contains thousands of compounds, including 69 known to be carcinogens, chemicals that are directly involved in causing cancer. Carcinogens can result in tumors by damaging the genome or disrupting the cell's metabolic processes.