SUNDAY, April 2, 2006 (HealthDay News) -- Preliminary research suggests that nicotine can cripple chemotherapy in lung cancer patients, even if it comes in a patch or gum designed to help a smoker quit the life-threatening habit.
The researchers only looked at a sampling of human cells in the laboratory, and they don't know if nicotine could potentially derail chemotherapy for other types of cancer.
Still, the findings suggest a simple message: "If you have cancer, stay away from nicotine -- smoking or patches or gum," said study co-author Srikumar Chellappan, an associate professor at the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla.
While nicotine is a major player in making tobacco addictive, its role in causing cancer is unclear. Other substances that make up tobacco smoke are considered more dangerous, which is why doctors consider it acceptable to use nicotine-based gum and patches to help smokers quit.
However, nicotine isn't entirely in the clear, with some research suggesting it could counteract cancer treatment. Chellappan and fellow researchers decided to see if it weakens chemotherapy, which targets tumor cells with poisonous chemicals.
In their new study, the researchers tested the effect of nicotine on lung cancer cells exposed to three types of chemotherapy drugs -- gemcitabine, cisplatin and taxol.
They report their findings in this week's issue of the Proceedings of the National Academy of Sciences and were scheduled to present them Sunday at the American Association for Cancer Research's annual meeting, in Washington, D.C.
The researchers discovered that the level of nicotine found in a typical smoker was enough to disrupt the chemotherapy drugs' ability to kill off the cancer cells.
By how much? "That we don't know, but in the studies, it's a major difference, a significant difference," Chellappan said.
According to him, nicotine appears to boost the levels of two proteins that protect cancer cells.
What's next? "There should be human studies to finally establish that this is a major red flag," Chellappan said.
For now, however, the research is very preliminary, cautioned Dr. Norman Edelman, chief medical officer of the American Lung Association. "There are so many differences between a living, walking human and a dish full of cells in a laboratory."
And while the study is "provocative and could be very important," Edelman added, it's important to consider that people who use nicotine patches or gum instead of cigarettes avoid taking in a variety of other poisons. This complicates the picture of just how harmful nicotine is in those forms -- especially since the patches and gums help people quit smoking in the first place.
Do people actually continue to smoke while they're undergoing treatment for lung cancer? Absolutely, said Edelman, adding, "It's not uncommon for smokers to continue smoking, especially those who are told they have cancer that's not really curable."
More information
Learn more about chemotherapy from the National Cancer Institute.
