It is known that tobacco and alcohol use are significant risk factors for developing esophageal squamous cell carcinoma (ESCC). Now, researchers have found that these two factors act synergistically. In their study, patients who smoked and drank had a twofold increased risk of ESCC compared with those who only smoked or drank.
In order to assess the combined effects of alcohol and tobacco on the risk of ESCC, researchers at the University of Michigan Medical School conducted a systematic review and meta-analysis of the current literature available in multiple electronic databases.
According to the study, either tobacco or alcohol use was associated with a 20–30 percent increased risk of ESCC compared with nonuse. However, the researchers observed that individuals who used both tobacco and alcohol had almost twice the risk of ESCC.
Although these results highlight the importance of focusing on the use of alcohol and tobacco in patients, the mechanism underlying this synergy remains unclear, the researchers said. They suggested that excessive smoking and drinking affect salivary levels of acetaldehyde, which has been identified as a possible cause of cancer. In addition, the effects of the consumption of both tobacco and alcohol might be compounded by other behaviors, such as poor oral health care, increasing the risk of ESCC.
The World Health Organization states that this esophageal cancer is much more frequent in Eastern countries and many developing countries than in Western countries. While in Western regions the incidence rate of this type of cancer does not exceed 5 per 100,000 in males and 1 per 100,000 in females, very high incidence rates have been identified in Iran, Central China, South Africa and Southern Brazil. In parts of China, for example, the mortality rate exceeds 100 per 100,000 in males and 50 in females.
Furthermore, the organization estimates that nearly 90 percent of squamous cell carcinoma cases can be attributed to tobacco and alcohol.
The study, titled “The Synergistic Effects of Alcohol and Tobacco Consumption on the Risk of Esophageal Squamous Cell Carcinoma: A Meta-Analysis,” was published online on April 22 in the American Journal of Gastroenterology ahead of print.