Smoking has been tied to an elevated risk of a common type of breast cancer among young women, providing a sober reminder that diseases caused by cigarettes go beyond respiratory and pulmonary problems.

The study, which is published in the journal Cancer, finds that younger women with a pack-a-day smoking history have a significantly higher incidence of so-called estrogen receptor-positive breast cancer, a common tumor characterized by its sensitivity to hormone-blocking therapy. Speaking to Reuters, lead author Christopher Li of the Fred Hutchinson Cancer Research Center said that the findings speak to the great range of cigarettes when it comes to adverse health outcomes. "There are so many different chemicals in cigarette smoke that can have so many kinds of effects," he explained. 

For their investigation, Li and colleagues surveyed 778 women with estrogen receptor-positive breast cancer, 182 with so-called triple-negative breast cancer, and 938 women who did not have breast cancer. Everyone in the sample was between 20 and 44 years old. Aside from their cancer status, participants were also asked to estimate their cigarette use over the past decade.

The team found that women who had been smoking at least one pack a day over the past 10 years were 60 percent more likely to develop estrogen receptor-positive breast cancer compared to women who had smoked fewer cigarettes or none at all. What’s more, women who had smoked at any point in their life — that is, consumed more than 100 cigarettes in their lifetime — had a 30 percent increased overall risk of breast cancer compared to women who had never smoked. The findings, the researchers said, clarify results from previous attempts to evaluate the relationship between breast cancer and smoking.

 "The current study adds to recent evidence indicating that smoking is modestly associated with breast cancer risk in young women,” Li and his colleagues told Medical News Today. “Expanding on earlier work, our findings suggest that this association is limited to an increase in the risk of estrogen receptor-positive breast cancer and that smoking does not have an impact on the risk of triple-negative breast cancer."

Breast Cancer: Latest Addition to Diseases Caused By Smoking

The current study is the latest in a series of attempts to bring to light the diverse consequences of smoking. Another example is a study from last year, in which researchers from Uppsala University in Sweden show that smoking not only harms the body, but our genes, too. So-called epigenetic alterations resulting from cigarette use gradually influence the activity of certain genes, making a user more likely to develop a host of complications, including diabetes, repressed immune system, and infertility.

 

Source: Li C, Kawai M, Malone K, et al. Active Smoking and the Risk of Estrogen Receptor-Positive and Triple-Negative Breast Cancer Among Women Ages 20 to 44 Years. Cancer. 2014.