According to a new study led by researchers at Harvard T.H. Chan School of Public Health, use of the smokeless tobacco product Snus may be associated with an increased risk of death among men with prostate cancer comparable to that associated with smoking. The finding is built on previous studies that show increased risk of death from prostate cancer in smokers with the disease. The study suggests that nicotine or other non-combustion-related components of tobacco may play a role in prostate cancer progression.
“Snus has been suggested as a less harmful alternative to smoking because it lacks the combustion products of smoking that are associated with cancer risk. However, we found that men with prostate cancer who used snus were at increased risk of premature death.”
Co-first author Kathryn Wilson, a Research Scientist in the Department of Epidemiology at Harvard Chan School.
Snus (pronounced like “goose”) is used mainly in Sweden but is also available in the United States. It is a powdered tobacco product, often sold in teabag-like sachets, that is placed under the upper lip for extended periods. It contains nicotine but no combustion components, and has not been previously studied in relation to prostate cancer survival. For the study researchers analyzed health data collected from Swedish construction workers during preventive health check-ups between 1971 and 1992, including a tobacco use questionnaire completed during each man`s initial check-up. Of these men, 9,582 later developed prostate cancer. About half of the subjects died during the follow-up period–2,489 from prostate cancer.
“There is some evidence from animal studies that nicotine can promote cancer progression, and snus users have high blood levels of nicotine. Even though it’s a smokeless product, snus users are also exposed to other carcinogens in tobacco.”
Study co-author Sarah Markt, a research associate at Harvard
Compared with those who never used tobacco, those who used snus but did not smoke had a 24% increased risk of dying from prostate cancer and a 19% increased risk of dying during the study period from any cause. Among men whose cancer had not spread, increased risk of death from prostate cancer for exclusive snus users was three times higher than for non-users of tobacco.
The study was published in the International Journal of Cancer.