Nicotine found to spur breast cancer growth
NEW YORK - Nicotine, whether absorbed by smoking cigarettes or inhaling second-hand smoke, may promote tumor growth and the spread of breast cancer, a study found.
Nicotine made breast cancer cells more likely to multiply and migrate in laboratory tests, according to the study published in yesterday's issue of the journal Cancer Research. Such evidence also suggests that nicotine given to help people stop smoking should be used cautiously.
Scientists had thought for some time that the toxic, cancer-causing components of cigarettes were ingredients other than nicotine, said Michael Thun, the head of epidemiology for the American Cancer Society in Atlanta, who wasn't involved in the study. Yesterday's study adds to other recent evidence that nicotine may also play a role in cancer, he said.
"Nicotine may have other adverse effects, in addition to addiction," Thun said in a telephone interview. "What it all adds up to is that the best thing you can do is avoid exposure to tobacco smoke."
The study on breast cancer cells was done in a lab dish rather than in the human body, so it's hard to tell what effect nicotine might have in people, said Chang Yan Chen, the study's lead author, who is a research scientist at Beth Israel Deaconess Medical Center in Boston.
"The role of nicotine is probably dependent on other factors, like genetic disposition," Chen said in a telephone interview. "Perhaps some individuals with certain genetic disadvantages might be more sensitive."
Nicotine is the main addictive drug in tobacco.