• 9/27/2007
  • Toronto, Ontario, Canada
  • Michael Smith, Senior Staff Writer, MedPage Today
  • MedPageToday.com

Stopping heavy drinking can significantly reduce the risk of esophageal and head-and-neck cancers, primarily squamous-cell carcinomas, researchers here said.

In a pooled analysis of 13 studies, those who quit heavy drinking saw their risk of esophageal cancer and head and neck cancer return to normal after 20 years, according to Jürgen Rehm, Ph.D., of the Centre for Addiction and Mental Health and colleagues.

But the first few years after stopping saw a significant rise in development of both types of cancer, he and colleagues reported in the September issue of the International Journal of Cancer.

The researchers postulated that the increase immediately after quitting was the result of what they called the “sick quitter” effect, in which patients stop drinking because they are already suffering symptoms of cancer, although it had not yet been diagnosed.

But after five years in the case of esophageal cancer and 10 years for head and neck cancers, the risk begins to drop, Dr. Rehm and colleagues said.

“Alcohol cessation has very similar effects on risk for head and neck cancers as smoking cessation has on lung cancer. Dr. Rehm said. “It
– takes about two decades before the risk is back to the risk of those who were never drinkers or never smokers.”

The finding comes from 13 case-control studies – five in esophageal cancer and eight in head and neck cancer – that included more than 5,000 cases, the researchers said. Most of the studies involved squamous-cell carcinoma.

Compared with current drinkers, people who have never used alcohol had a risk ratio for esophageal cancer of 0.37 and for head and neck cancers of 0.46. Both risk reductions were significant at P<0.001.

For former drinkers (compared with current drinkers) the risk first rose and then fell:

– The risk ratio for esophageal cancer in the first two years after stopping was 2.5, with a 95% confidence interval from 2.23 to 2.80, which was significant at P<0.001.

– Between five and 10 years after stopping, the risk of esophageal cancer was significantly reduced (at P<0.001) with a risk ratio of 0.85 and a 95% confidence interval from 0.78 to 0.92.

– By 15 years, the risk ratio for esophageal cancer was the same as that for a person who had never used alcohol – 0.37.

– The risk for head and neck cancers remained high for the first 10 years after going on the wagon. The risk ratio for people between five and 10 years after they quit was 1.26, with a 95% confidence interval from 1.18 to 1.35, which was significant at P<0.001.

– But between 10 and 15 years later, the risk ratio was 0.67, with a 95% confidence interval from 0.63 to 0.73, which was significant at P<0.001.

The risks did not change substantially when the researchers adjusted for smoking.

Dr. Rehm and colleagues noted that the study is limited because they treated drinking as an all-or-nothing issue, and were unable to estimate dose-response effects.

They also noted the analysis is entirely based on retrospective studies, which opens the door to various errors, including recall bias.

Nonetheless, they said, the study is comprehensive and provides the most accurate available odds ratios for alcohol cessation. “The risk reductions are quite large, especially for esophageal cancer,” they said.

The study was supported by Public Works and Government Services Canada.