Increased Adenocarcinoma Type Lung Cancer - Cigarette Design..

May 3, 2009 - Up to one half of current lung cancer occurrence could be attributable to cigarette design, according to David Burns and Christy Anderson of the University of California at San Diego School of Medicine. The study examined lung cancer rates as well as changes in the design and smoke composition of both American and Australian cigarettes over the last four decades. Both countries saw a rise in the use of low tar cigarettes, as well as the introduction of ventilated filters.

Decades ago, squamous cell carcinoma was the most common form of lung cancer. But between 1950 and 2007, adenocarcinoma became the most frequently diagnosed lung malignancy, as the market share of filtered cigarettes soared from just 1 percent to almost 100 percent. (Filtered Cigarettes Blamed for Huge Rise in Type of Lung Cancer Women's Health in the News, 9/6/2007) Women are more likely than men to develop a type of cancer called adenocarcinoma. The reason is not known, though adenocarcinoma is the most common lung cancer among nonsmokers, and women are less likely than men to smoke. (Lung Cancer Affects Sexes Differently by Denise Grady, The New York Times, 4/14/2004.)

The major known difference in cigarettes between the two countries is the level of tobacco-specific nitrosamines, a lung-specific carcinogen that causes adenocarcinoma--one of the four major cell types of lung cancer. Nitrosamines are found in far higher levels in American cigarettes than in Australian cigarettes, the study reports.

Poster Session: David Burns and Christy Anderson, University of California San Diego presented their results at the Joint Conference of the Society for Research in Nicotine and Tobacco (SRNT and SRNT-Europe), April 27-30, 2009, Dublin Ireland, TITLE: Is the Increase in Adenocarcinoma A Result of Changes in Cigarette Design, ABSTRACT..

David Sutton, a spokesperson for tobacco company PhilipMorrisUSA, said his company has been aware of concerns over nitrosamines for some time and has taken steps to reduce the levels of the carcinogen in tobacco. For instance, the company requires its tobacco growers to use indirect heating systems during the curing process to prevent the tobacco from being exposed to the combustion gases that increase the presence of nitrosamines. For growers that do not use a heat-based curing system, PhilipMorrisUSA requires the use of a tobacco seed that has been shown to produce less nitrosamines.

Poster Session Summary:
1) The study provides new evidence that among smokers there has been an increase in the risk of developing lung cancer, controlling for amount and duration of smoking, which has progressively increased in the US over the past four decades.
2) This increase in the risk of lung cancer among smokers coincides with a change in cigarette design over the past five decades.
3) This increase in risk of smoking over time is not evident for squamous cell carcinoma of the lung and is driven largely by changes in the risk of adenocarcinoma. The increase in adenocarcinoma as a proportion of all lung cancers is much less evident in Australia. This suggests that the difference may be caused by a difference in the cigarettes used in the two countries. One major known differences in cigarettes between the two countries is the lower levels of tobacco specific nitrosamines (a lung specific carcinogen for adenocarcinoma) in Australian cigarettes. The increased risk of adenocarcinoma in the US may be explained by the higher levels of tobacco specific nitrosamines in US cigarettes.
4) These observations strongly support the need for regulation of tobacco products, since technology exists to lower nitrosamines in tobacco.

Poster Session..

References: Are Cigarettes More Hazardous Than Ever? Risk of getting lung cancer has increased due to chnages in design, new study suggests by Stephanie Condon, CBS News, 4/30/2009; New Study Indicates Changes in Cigarette Design Have Increased Lung Cancer Risk and Tobacco Regulation Can Greatly Reduce Lung Cancer, redorbit.com, 5/1/2009.