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Alcohol and CRC: These Drinking Patterns May Influence Risk
New research sheds light on how chronic heavy alcohol use may contribute to colorectal cancer (CRC) development and how quitting may lower the risk for precancerous colorectal adenomas.
In a large US cancer screening trial, current heavy drinkers — with an average lifetime alcohol intake of 14 or more drinks per week — had a 25% higher risk for CRC and an almost twofold higher risk for rectal cancer than light drinkers averaging less than one drink per week.
When the research team further considered drinking consistency, steady heavy drinking throughout adulthood was associated with a 91% higher risk for CRC than consistent light drinking.
Additionally, no increased risk for CRC was found among former drinkers, and former drinkers were less likely than light drinkers to develop nonadvanced colorectal adenomas.
This analysis “adds to the growing amount of concerning literature showing that chronic heavy alcohol use can potentially contribute to colorectal cancer development,” Benjamin H. Levy III, MD, gastroenterologist and clinical associate of medicine at UChicago Medicine in Chicago, who wasn’t involved in the study, told Medscape Medical News.
The study’s co-senior author, Erikka Loftfield, PhD, MPH, also noted that the study “provides new evidence indicating that drinking cessation, compared to consistent light drinking, may lower adenoma risk.”
Current cancer prevention guidelines recommend limiting alcohol intake or ideally not drinking at all, and “our findings do not change this advice,” said Loftfield, with the National Cancer Institute (NCI) in Bethesda, Maryland.
The study was published online on January 26 in the journal Cancer.
Addressing a Data Gap
Alcoholic beverages are classified as carcinogenic to humans and are causally associated with CRC, Loftfield told Medscape Medical News. However, much of the evidence for this comes from cohort studies that only measure recent drinking patterns, generally among older adults, at study baseline. Fewer studies have looked at how drinking over a person’s lifetime and alcohol consumption patterns relate to colorectal adenoma and CRC risk, she explained.
To address these gaps, Loftfield and colleagues leveraged data on alcohol intake gathered as part of the NCI’s Prostate, Long, Colorectal, and Ovarian Cancer Screening Trial.
Average lifetime alcohol intake was calculated as drinks per week from age 18 through study baseline, and drinking patterns were further classified based on consistency and intensity over time.
During 20 years of follow-up, 1679 incident CRC cases occurred among 88,092 study participants. In multivariable-adjusted analyses, current heavy drinkers had a higher risk for CRC than those averaging less than one drink per week (hazard ratio [HR], 1.25), with the strongest association observed for rectal cancer (HR, 1.95).
“The increase in rectal cancer risk for heavy drinkers seen in this 20-year observational study was especially concerning,” Levy told Medscape Medical News.
What About Moderate Drinking?
Perhaps counterintuitively, moderate current drinkers (those consuming an average of 7 to less than 14 drinks per week) had a lower risk for CRC (HR, 0.79), especially distal colon cancer (HR, 0.64), than light drinkers.
Loftfield said that research in rodents suggests moderate alcohol intake may reduce inflammation and lower DNA damage, but it’s possible that the observed inverse association is due to residual confounding by unmeasured or poorly measured confounders, such as socioeconomic status.
She said it’s also important to note that the inverse association of moderate alcohol intake was strongest for distal colon cancer and in the screening arm of the trial. Those in the screening arm who screened positive with flexible sigmoidoscopy had polyps removed and were referred for colonoscopy during the trial period, making screening a potential intervention as well.
“Screening with flexible sigmoidoscopy has previously been found to decrease CRC incidence, specifically distal colon cancer, in this population. Thus, it is possible that better adherence to screening among moderate drinkers over the course of follow-up contributed to this finding,” Loftfield explained.
When looking at consistency of drinking, her team found that current drinkers who were consistent heavy drinkers throughout adulthood had a higher risk for CRC than consistent light drinkers (HR, 1.91).
Separate analyses of incident colorectal adenomas were directionally consistent with the CRC findings. These analyses included 12,327 participants with a negative baseline sigmoidoscopy, among whom 812 adenomas were detected on repeat screening.
Compared with current light drinkers, former drinkers had significantly lower odds of nonadvanced adenomas (odds ratio [OR], 0.58), but no significant association was observed for advanced adenomas (OR, 1.08; 95% CI, 0.62-1.90). The authors cautioned, however, that overall adenoma case numbers were limited, and estimates for advanced lesions were imprecise.
Educating Patients
Reached for comment, William Dahut, chief scientific officer for the American Cancer Society, told Medscape Medical News that this “very well done, large perspective study clearly demonstrates the significant increased risk of colorectal cancer for those that are heavy drinkers.”
He noted that the nearly twofold increased risk for rectal cancer among heavy drinkers “makes biological sense because the rectum is the area of the body where the toxins produced by alcohol potentially spend the most period of time.”
Heavy drinkers are at the highest risk, Dahut said, and “for them, screenings are particularly important.”
Even with this growing body of evidence, Levy noted that many patients in America and worldwide “have not been educated yet about the potential carcinogenic dangers of chronic alcohol use.”
Levy recommended that physicians get “accurate social histories about alcohol use” and “spend several minutes educating patients about their increased risk of cancer and liver problems from heavy alcohol use.”
Dahut encouraged health providers to tell patients that the risk for CRC from alcohol is also based on one’s lifetime alcohol consumption, “not simply what they had last weekend.”
Overall, this important research study, along with the Surgeon General’s recent publication about Alcohol and Cancer Risk, will hopefully “encourage physicians to have important conversations about alcohol reduction with their patients,” Levy said.
The study had no commercial funding. Loftfield, Dahult, and Levy reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
New research sheds light on how chronic heavy alcohol use may contribute to colorectal cancer (CRC) development and how quitting may lower the risk for precancerous colorectal adenomas.
In a large US cancer screening trial, current heavy drinkers — with an average lifetime alcohol intake of 14 or more drinks per week — had a 25% higher risk for CRC and an almost twofold higher risk for rectal cancer than light drinkers averaging less than one drink per week.
When the research team further considered drinking consistency, steady heavy drinking throughout adulthood was associated with a 91% higher risk for CRC than consistent light drinking.
Additionally, no increased risk for CRC was found among former drinkers, and former drinkers were less likely than light drinkers to develop nonadvanced colorectal adenomas.
This analysis “adds to the growing amount of concerning literature showing that chronic heavy alcohol use can potentially contribute to colorectal cancer development,” Benjamin H. Levy III, MD, gastroenterologist and clinical associate of medicine at UChicago Medicine in Chicago, who wasn’t involved in the study, told Medscape Medical News.
The study’s co-senior author, Erikka Loftfield, PhD, MPH, also noted that the study “provides new evidence indicating that drinking cessation, compared to consistent light drinking, may lower adenoma risk.”
Current cancer prevention guidelines recommend limiting alcohol intake or ideally not drinking at all, and “our findings do not change this advice,” said Loftfield, with the National Cancer Institute (NCI) in Bethesda, Maryland.
The study was published online on January 26 in the journal Cancer.
Addressing a Data Gap
Alcoholic beverages are classified as carcinogenic to humans and are causally associated with CRC, Loftfield told Medscape Medical News. However, much of the evidence for this comes from cohort studies that only measure recent drinking patterns, generally among older adults, at study baseline. Fewer studies have looked at how drinking over a person’s lifetime and alcohol consumption patterns relate to colorectal adenoma and CRC risk, she explained.
To address these gaps, Loftfield and colleagues leveraged data on alcohol intake gathered as part of the NCI’s Prostate, Long, Colorectal, and Ovarian Cancer Screening Trial.
Average lifetime alcohol intake was calculated as drinks per week from age 18 through study baseline, and drinking patterns were further classified based on consistency and intensity over time.
During 20 years of follow-up, 1679 incident CRC cases occurred among 88,092 study participants. In multivariable-adjusted analyses, current heavy drinkers had a higher risk for CRC than those averaging less than one drink per week (hazard ratio [HR], 1.25), with the strongest association observed for rectal cancer (HR, 1.95).
“The increase in rectal cancer risk for heavy drinkers seen in this 20-year observational study was especially concerning,” Levy told Medscape Medical News.
What About Moderate Drinking?
Perhaps counterintuitively, moderate current drinkers (those consuming an average of 7 to less than 14 drinks per week) had a lower risk for CRC (HR, 0.79), especially distal colon cancer (HR, 0.64), than light drinkers.
Loftfield said that research in rodents suggests moderate alcohol intake may reduce inflammation and lower DNA damage, but it’s possible that the observed inverse association is due to residual confounding by unmeasured or poorly measured confounders, such as socioeconomic status.
She said it’s also important to note that the inverse association of moderate alcohol intake was strongest for distal colon cancer and in the screening arm of the trial. Those in the screening arm who screened positive with flexible sigmoidoscopy had polyps removed and were referred for colonoscopy during the trial period, making screening a potential intervention as well.
“Screening with flexible sigmoidoscopy has previously been found to decrease CRC incidence, specifically distal colon cancer, in this population. Thus, it is possible that better adherence to screening among moderate drinkers over the course of follow-up contributed to this finding,” Loftfield explained.
When looking at consistency of drinking, her team found that current drinkers who were consistent heavy drinkers throughout adulthood had a higher risk for CRC than consistent light drinkers (HR, 1.91).
Separate analyses of incident colorectal adenomas were directionally consistent with the CRC findings. These analyses included 12,327 participants with a negative baseline sigmoidoscopy, among whom 812 adenomas were detected on repeat screening.
Compared with current light drinkers, former drinkers had significantly lower odds of nonadvanced adenomas (odds ratio [OR], 0.58), but no significant association was observed for advanced adenomas (OR, 1.08; 95% CI, 0.62-1.90). The authors cautioned, however, that overall adenoma case numbers were limited, and estimates for advanced lesions were imprecise.
Educating Patients
Reached for comment, William Dahut, chief scientific officer for the American Cancer Society, told Medscape Medical News that this “very well done, large perspective study clearly demonstrates the significant increased risk of colorectal cancer for those that are heavy drinkers.”
He noted that the nearly twofold increased risk for rectal cancer among heavy drinkers “makes biological sense because the rectum is the area of the body where the toxins produced by alcohol potentially spend the most period of time.”
Heavy drinkers are at the highest risk, Dahut said, and “for them, screenings are particularly important.”
Even with this growing body of evidence, Levy noted that many patients in America and worldwide “have not been educated yet about the potential carcinogenic dangers of chronic alcohol use.”
Levy recommended that physicians get “accurate social histories about alcohol use” and “spend several minutes educating patients about their increased risk of cancer and liver problems from heavy alcohol use.”
Dahut encouraged health providers to tell patients that the risk for CRC from alcohol is also based on one’s lifetime alcohol consumption, “not simply what they had last weekend.”
Overall, this important research study, along with the Surgeon General’s recent publication about Alcohol and Cancer Risk, will hopefully “encourage physicians to have important conversations about alcohol reduction with their patients,” Levy said.
The study had no commercial funding. Loftfield, Dahult, and Levy reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
New research sheds light on how chronic heavy alcohol use may contribute to colorectal cancer (CRC) development and how quitting may lower the risk for precancerous colorectal adenomas.
In a large US cancer screening trial, current heavy drinkers — with an average lifetime alcohol intake of 14 or more drinks per week — had a 25% higher risk for CRC and an almost twofold higher risk for rectal cancer than light drinkers averaging less than one drink per week.
When the research team further considered drinking consistency, steady heavy drinking throughout adulthood was associated with a 91% higher risk for CRC than consistent light drinking.
Additionally, no increased risk for CRC was found among former drinkers, and former drinkers were less likely than light drinkers to develop nonadvanced colorectal adenomas.
This analysis “adds to the growing amount of concerning literature showing that chronic heavy alcohol use can potentially contribute to colorectal cancer development,” Benjamin H. Levy III, MD, gastroenterologist and clinical associate of medicine at UChicago Medicine in Chicago, who wasn’t involved in the study, told Medscape Medical News.
The study’s co-senior author, Erikka Loftfield, PhD, MPH, also noted that the study “provides new evidence indicating that drinking cessation, compared to consistent light drinking, may lower adenoma risk.”
Current cancer prevention guidelines recommend limiting alcohol intake or ideally not drinking at all, and “our findings do not change this advice,” said Loftfield, with the National Cancer Institute (NCI) in Bethesda, Maryland.
The study was published online on January 26 in the journal Cancer.
Addressing a Data Gap
Alcoholic beverages are classified as carcinogenic to humans and are causally associated with CRC, Loftfield told Medscape Medical News. However, much of the evidence for this comes from cohort studies that only measure recent drinking patterns, generally among older adults, at study baseline. Fewer studies have looked at how drinking over a person’s lifetime and alcohol consumption patterns relate to colorectal adenoma and CRC risk, she explained.
To address these gaps, Loftfield and colleagues leveraged data on alcohol intake gathered as part of the NCI’s Prostate, Long, Colorectal, and Ovarian Cancer Screening Trial.
Average lifetime alcohol intake was calculated as drinks per week from age 18 through study baseline, and drinking patterns were further classified based on consistency and intensity over time.
During 20 years of follow-up, 1679 incident CRC cases occurred among 88,092 study participants. In multivariable-adjusted analyses, current heavy drinkers had a higher risk for CRC than those averaging less than one drink per week (hazard ratio [HR], 1.25), with the strongest association observed for rectal cancer (HR, 1.95).
“The increase in rectal cancer risk for heavy drinkers seen in this 20-year observational study was especially concerning,” Levy told Medscape Medical News.
What About Moderate Drinking?
Perhaps counterintuitively, moderate current drinkers (those consuming an average of 7 to less than 14 drinks per week) had a lower risk for CRC (HR, 0.79), especially distal colon cancer (HR, 0.64), than light drinkers.
Loftfield said that research in rodents suggests moderate alcohol intake may reduce inflammation and lower DNA damage, but it’s possible that the observed inverse association is due to residual confounding by unmeasured or poorly measured confounders, such as socioeconomic status.
She said it’s also important to note that the inverse association of moderate alcohol intake was strongest for distal colon cancer and in the screening arm of the trial. Those in the screening arm who screened positive with flexible sigmoidoscopy had polyps removed and were referred for colonoscopy during the trial period, making screening a potential intervention as well.
“Screening with flexible sigmoidoscopy has previously been found to decrease CRC incidence, specifically distal colon cancer, in this population. Thus, it is possible that better adherence to screening among moderate drinkers over the course of follow-up contributed to this finding,” Loftfield explained.
When looking at consistency of drinking, her team found that current drinkers who were consistent heavy drinkers throughout adulthood had a higher risk for CRC than consistent light drinkers (HR, 1.91).
Separate analyses of incident colorectal adenomas were directionally consistent with the CRC findings. These analyses included 12,327 participants with a negative baseline sigmoidoscopy, among whom 812 adenomas were detected on repeat screening.
Compared with current light drinkers, former drinkers had significantly lower odds of nonadvanced adenomas (odds ratio [OR], 0.58), but no significant association was observed for advanced adenomas (OR, 1.08; 95% CI, 0.62-1.90). The authors cautioned, however, that overall adenoma case numbers were limited, and estimates for advanced lesions were imprecise.
Educating Patients
Reached for comment, William Dahut, chief scientific officer for the American Cancer Society, told Medscape Medical News that this “very well done, large perspective study clearly demonstrates the significant increased risk of colorectal cancer for those that are heavy drinkers.”
He noted that the nearly twofold increased risk for rectal cancer among heavy drinkers “makes biological sense because the rectum is the area of the body where the toxins produced by alcohol potentially spend the most period of time.”
Heavy drinkers are at the highest risk, Dahut said, and “for them, screenings are particularly important.”
Even with this growing body of evidence, Levy noted that many patients in America and worldwide “have not been educated yet about the potential carcinogenic dangers of chronic alcohol use.”
Levy recommended that physicians get “accurate social histories about alcohol use” and “spend several minutes educating patients about their increased risk of cancer and liver problems from heavy alcohol use.”
Dahut encouraged health providers to tell patients that the risk for CRC from alcohol is also based on one’s lifetime alcohol consumption, “not simply what they had last weekend.”
Overall, this important research study, along with the Surgeon General’s recent publication about Alcohol and Cancer Risk, will hopefully “encourage physicians to have important conversations about alcohol reduction with their patients,” Levy said.
The study had no commercial funding. Loftfield, Dahult, and Levy reported no relevant disclosures.
A version of this article first appeared on Medscape.com.
Alcohol and CRC: These Drinking Patterns May Influence Risk
Alcohol and CRC: These Drinking Patterns May Influence Risk