aAlthough light and moderate levels of alcohol consumption do not increase the risk of liver cancer, heavy drinking increases the risk substantially.
and liquor, the type of alcohol consumed does not appear to influence the cancer risk as much as does the amount consumed (World Cancer Research Fund and American Institute for Cancer Research, 1997). For cancers of the upper aerodigestive tract, breast, colon, and rectum, there is a dose-response relationship, such that even low or moderate levels of consumption increase risk slightly. For liver cancer, the most important factor is heavy and persistent use, such as that defined by alcoholism, which can cause chronic liver injury.
Alcohol Consumption and Cancers of the Mouth, Pharynx, Larynx, and Esophagus
There is convincing epidemiological evidence from both cohort and case-control studies that alcohol consumption increases the risk of cancers of the mouth, pharynx, larynx, and esophagus (World Cancer Research Fund and American Institute for Cancer Research, 1997; Kjaerheim et al., 1998). All of the cohort studies that have examined this association, including those that controlled for smoking, have demonstrated a substantially increased risk. In addition, a dose-response relationship has been observed in the majority of case-control studies, including most of those that controlled for smoking. Alcohol also appears to act synergistically with tobacco in causing these cancers (World Cancer Research Fund and American Institute for Cancer Research, 1997).
Several mechanisms have been proposed to explain the carcinogenic effect of alcohol on cancers of the upper aerodigestive tracts, although none are proven (World Cancer Research Fund and American Institute for Cancer Research, 1997). Alcohol may directly influence carcinogenesis in the cells that it touches; it may alter the permeabilities of cell membranes or modify cellular metabolism, thus making these cells more vulnerable to chemical carcinogens;