April 3, 2006 (Washington) -- Nicotine supplements such as patches or gum may weaken the potent punch that chemotherapy drugs pack against tumor cells in people with lung cancer.
So suggests a new study that indicates nicotine can prevent chemotherapy drugs such as taxol from killing lung cancer cells. It's a finding that may help explain why people with lung cancer who continue to smoke have such a poor prognosis.
The study, presented here at the annual meeting of the American Association for Cancer Research, was also released in the online edition of the Proceedings of the National Academy of Sciences.
Nicotine and Cancer Cells
The researchers studied nicotine's effects on the performance of three of the most commonly used drugs to treat lung cancer: gemcitabine, cisplatin, and taxol. Normally the drugs cause cancer cells to kill themselves off in a process called apoptosis.
Working in the lab, they added the drugs to cell samples taken from lung cancer tumors.
Adding nicotine to the mix -- about what would be found in the blood of a heavy smoker -- significantly interfered with the drug's ability to kill cancer cells.
"Nicotine prevented apoptosis, or cancer-cell suicide," says researcher Piyali Dasgupta, PhD, of the H. Lee Moffitt Cancer Center in Tampa, Fla.
Nicotine protected the cells by activating two genes -- XIAP and survivin -- that prevented the cells from undergoing apoptosis.
The research focused on human non-small cell lung cancer, which accounts for nearly four-fifths of all lung cancers.
Cancer Patients and Smoking
Dasgupta tells WebMD that patches deliver at least 100-fold less nicotine to the blood than cigarette smoking itself. "Nonetheless there's a possibility they can also interfere with the drugs' ability to kill cancer cells," she says.
Nithya Ramnath, MD, a lung cancer specialist at the Roswell Park Cancer Institute in Buffalo, N.Y., agrees.
This is one of several studies showing that people with lung cancer who continue to smoke face a bleaker outlook than those who quit before treatment, she says.
While the findings need confirmation in human studies, they also raise the possibility that nicotine supplements might reduce the response to chemotherapy, she says.
"I wouldn't go so far as to say people shouldn't use supplements until we have further data," Ramnath tells WebMD. "But I would tell patients that there are data out there suggesting that other aids, such as hypnosis or biofeedback, might be preferable."
"The most important thing is to quit smoking," she says.