Tobacco Smoke Causes Inflammation, Promotes Cancer Growth

Repeated exposure to tobacco smoke makes lung cancer much worse, and one reason is that it steps up inflammation in the lung. Scientists at the University of California, San Diego School of Medicine have found that mice with early lung cancer lesions that were repeatedly exposed to tobacco smoke developed larger tumors – and developed tumors more quickly – than unexposed animals. The key contributing factor was lung tissue inflammation.

The results of their study, to be published January 19 in the journal Cancer Cell, provide definitive evidence for the role of lung inflammation brought on by chronic exposure to tobacco smoke in promoting lung cancer growth. The findings also establish new lung cancer models, provide insights into both the development and growth of lung cancer, and suggest the possibility of using anti-inflammatory agents to prevent or slow lung cancer progression, said Michael Karin, PhD, Distinguished Professor of Pharmacology and Pathology at the UC San Diego School of Medicine, who led the work.

“We’ve shown for the first time that tobacco smoke is a tumor promoter – not only a tumor initiator – and that it works through inflammation,” said Karin, director of the Laboratory of Gene Regulation and Signal Transduction and a member of the Moores UCSD Cancer Center. “Other particulate materials, such as fine silicon dust, asbestos and coal dust, may promote lung cancer development through similar mechanisms. Such substances were never found to induce mutations, which are the essence of tumor formation. More research is needed to explore the role and biochemical mechanisms of exposure to pro-inflammatory substances in the environment in early stages of cancer development.”

Lung cancer killed nearly 160,000 Americans in 2009, according to the American Cancer Society, making it the leading cause of cancer death in both men and women. Read more

Diet May Protect Against Lung Cancer In Smokers

Leafy green vegetables, folate, and some multivitamins could serve as protective factors against lung cancer in current and former smokers, according to a study that is a first step in understanding a complex association. The study was led by Steve Belinsky, Ph.D. and other researchers at the institute in ABQ, NM. It was supported by the National Cancer Institute (NCI), part of the National Institutes of Health. The study appeared online Jan. 12, 2010, in Cancer Research .

Researchers examined cells that were coughed up by current and former smokers for gene methylation, a chemical modification used by the cell to control gene expression. Upon careful study of the cells and by comparing those cells with profiles of smokers’ dietary intake of leafy green vegetables, folate, and some multivitamins, they found an association between those particular substances was associated with a reduced prevalence for cellular gene methylation.

As seen in previous studies, gene methylation is likely to be a major mechanism in lung cancer development and progression, as well as a potential marker for the early detection of lung cancer. Dr. Belinsky said, “This study suggests that diet and dietary supplements could help in preventing lung cancer.” Read more

Grant Funds New System To Diagnose And Treat Lung Cancer On-The-Spot

Scientists at The Methodist Hospital Research Institute in Houston received a research grant from the Cancer Prevention Research Institute of Texas (CPRIT) today to develop the first molecular image guided system to diagnose and treat small-cell peripheral lung cancer in one sitting.

“Despite our best efforts to accurately diagnose and treat lung cancer, it is still the most common cause of cancer-related death in America,” said Dr. Stephen Wong, principle investigator for the study and director of the Center for Biotechnology and Informatics at The Methodist Hospital Research Institute. “With this grant, we plan to create a system to diagnose the cancer earlier, then treat it immediately in the earliest stages of the disease.”

Wong’s team will design a user-friendly 3D visualization and navigation platform that will allow physicians to quickly and accurately guide a needle to the small nodules of potential cancer in patients’ lungs. Once in the nodule, they will use molecular imaging to get a viable tissue sample through a fine-needle aspiration biopsy. Then if cancer is detected, they will use radiofrequency ablation to treat the cancer immediately on the spot.

Currently, typical lung cancer diagnoses are reached after four different imaging studies, both non-invasive and much more invasive, such as percutaneous biopsies and subsequent transthoracic CT-guided needle biopsies. These studies typically take place over the course of days or weeks, and are then followed by treatment. Read more

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