Heavy Drinking Linked to 25% Higher Risk

• A recent study indicates that higher lifetime alcohol consumption may raise the risk of colorectal cancer.
• The findings show that heavy drinking is associated with the highest risk, particularly rectal cancer, and that former drinkers had a lower risk.
• The research suggests that lower lifetime alcohol consumption may help reduce the overall risk of developing cancer.

Colorectal cancer is cancer that starts in either the colon or the rectum. It might also be called colon cancer or rectal cancer, depending on where it originates.

According to the American Cancer Society (ACS), colorectal cancer is the third leading cause of cancer-related deaths in males, and the fourth leading cause in females. When these groups are combined, colorectal cancer is the second most common cause of cancer-related deaths.

A recent study published in Cancer found that people with a higher lifetime consumption of alcohol may be at a higher risk of developing colorectal cancer.

“Our study is one of the first to explore how drinking alcohol over the life course relates to both colorectal adenoma and colorectal cancer risk,” co–senior author Erikka Loftfield, PhD, MPH, of the NCI, part of the National Institutes of Health (NIH), noted in a press release.

“While the data on former drinkers were sparse, we were encouraged to see that their risk may return to that of the light drinkers,” Loftfield continued.

The team observed that 1,679 colorectal cancer cases occurred among 88,092 participants over the course of a median follow-up of 14.5 years.

The findings show that those with average alcohol consumption of 14 or more drinks per week had a 25% higher risk of developing colorectal cancer. Average alcohol use was also associated with a 95% higher risk of developing rectal cancer.

These findings were compared to those with a lifetime average of consuming 1 drink or less per week.

When the researchers examined drinking consistency, they found that heavy drinking (14 or more drinks per week) was associated with a 91% higher risk of colorectal cancer compared with consistent light drinking (1 drink or less per week).

In contrast, when they observed former drinkers, they found no evidence of an increased risk of developing colorectal cancer.

Former drinkers also showed a lower risk of developing noncancerous colorectal tumors (adenomas), which may go on to become cancerous. This was in comparison to current light drinkers. These findings may indicate that alcohol cessation can lower a person’s risk.

“This study provides hope that it is never too late to reduce alcohol consumption since this can lead to fewer colon polyps and potentially cancer reduction,” said Anton Bilchik, MD, PhD, surgical oncologist, chief of medicine and Director of the Gastrointestinal and Hepatobiliary Program at Providence Saint John’s Cancer Institute in Santa Monica, CA. Bilchik wasn’t involved in the study.

However, the researchers note that the data for their findings were limited.

Alcohol’s effect on colorectal cancer risk may be associated with carcinogens produced from alcohol metabolism or alcohol’s effects on gut microbes. More research is needed to test whether these mechanisms are involved.

“The results of this observational study were not very straightforward and raise the question about how accurate a survey-based study like this can be,” said Timothy Cannon, MD, Sheridan Director, Molecular Tumor Board and Co-Director of the Gastrointestinal Cancer Program at Inova. Cannon wasn’t involved in the study.

Other lifestyle-related risk factors than alcohol consumption include:

“This study provides further insight into how important lifestyle, diet, and alcohol use are in the development of cancer, but that cancer risk can be reduced by paying attention to all these factors,” said Bilchik.

Risk factors that you cannot change include:

If you have any questions or concerns about your risk of colorectal cancer, speak with a healthcare professional.

“Colorectal cancer is now the leading cause of cancer death in people under 50, and its incidence has essentially doubled since the 1970s,” said Cannon.

“This increase has been predominantly in left-sided colon cancers, and I found it interesting that this study showed that alcohol induced colorectal cancer also seems to be predominantly left-sided. Future studies should assess how alcohol might contribute to this epidemic,” Cannon said.