Underreporting of Alcohol Intake Affects the Relation of Alcohol to the Risk of Cancer

People with certain adverse health effects who report very low levels of alcohol consumption are often assumed to be underreporting their intake. Investigators reviewed 127,176 patients’ medical records for diseases and conditions that are known to occur predominantly in people with heavy alcohol use (e.g., liver cirrhosis, alcoholic neuropathy, and alcoholism). Subjects with such diagnoses who reported “light” (average <1 drink in a day) or “moderate” (average 1–2 drinks in a day) alcohol use were considered to be “likely underreporters” of their alcohol intake (18%). Subjects reporting the same levels of consumption with no evidence of risky alcohol use in their records (47%) were classified as “unlikely underreporters.” During an average follow-up period of 18 years, 14,880 subjects developed cancer. There were 23,363 subjects who reported “light” or “moderate” alcohol consumption.

• Compared with abstainers, in subjects considered to be unlikely underreporters with “moderate” alcohol use the relative risk of any type of cancer was 0.98. In contrast, for those categorized as likely underreporters the relative risk of cancer was 1.33.
• Similar results were seen for “alcohol-related cancers.” The risk of breast cancer among women was less than one-half as high among those with “moderate” alcohol use who were considered unlikely underreporters compared with those considered likely underreporters.

Comments:

This study shows that the increase in the risk of any cancer among people who consume <1 to 2 drinks in a day seems to occur primarily among those who may be underreporting their alcohol intake. This approach could be a valuable strategy for seeking the relation between alcohol intake and cancer as well as other health outcomes.

R. Curtis Ellison, MD

Reference:

Klatsky AL, Udaltsova N, Li Y, et al. Moderate alcohol intake and cancer: the role of underreporting. Cancer Causes Control. 2014;25(6):693–699.