IASLC: Rise in Adenocarcinoma of the Lung Tied to Cigarette Design Changes

SEOUL, South Korea, Sept. 10 -- The predominance of adenocarcinoma histology in lung cancer resulted from changes in cigarette design that allowed cancer-causing chemicals to penetrate deeper into airways, a long-time critic of the tobacco industry asserted here.

With the introduction of vented cigarette filters in the 1960s and '70s, smokers could "take bigger, deeper puffs," Gary Strauss, M.D., of Tufts University in Boston, told attendees at the International Association for the Study of Lung Cancer's world conference.

The filters were part of an industry effort to sell the public on the concept of safer cigarettes, an effort that included the introduction of so-called light and ultralight brands, Dr. Strauss said.

"The tobacco industry intentionally deceived consumers regarding the hazards of the changing cigarette, translating into the creation of a new and deadly epidemic of smoking-related adenocarcinoma of the lung," he said.

In a featured presentation at the meeting's Presidential Symposium, Dr. Strauss linked changes in cigarette design and subsequent increased consumption of filtered cigarettes to the emergence of adenocarcinoma histology.

The information on lung cancer histology came from the federal government's Surveillance, Epidemiology, and End Results (SEER) database. Dr. Strauss acknowledged that SEER does not include information on patients' smoking status.

As a consequence, the link to adenocarcinoma of the lung is implied, in that the histology's rise to predominance occurred at the same time as the changes in cigarette design.

Dr. Strauss acknowledged the circumstantial nature of the link by stating more than once that his findings were "consistent with the hypothesis that changes in cigarette design and composition were responsible for this increase."

From a historical perspective, the association between cigarette smoking and lung cancer was established in the 1950s. At that time, however, adenocarcinoma constituted about 5% of all lung cancers and was only weakly related to smoking, said Dr. Strauss.

During the 1960s and '70s, the incidence of adenocarcinoma increased sharply, Dr. Strauss said. From 1975 to 1979 adenocarcinoma became the most common form of lung cancer in men and in younger smokers. By the period from 1990 to 1994, adenocarcinoma had become the predominant form of lung cancer in both sexes, all age groups, and blacks and whites.

Dr. Strauss also catalogued the timing of changes in cigarette design. In 1950, filtered brands accounted for about 1% of all cigarette consumption in the U.S., he said. By 1964, filtered cigarettes constituted 64% of the market, and since 1986, filtered brands have accounted for more than 90% of the cigarette market.

Along with widespread adoption of filtered cigarettes, Dr. Strauss said, the amount of tar and nicotine delivered in the typical cigarette decreased. However, changes in tobacco blend led to an increase in the nitrosamine concentration. The advent of ventilated filters "likely played a substantial role in the rise of adenocarcinoma," said Dr. Strauss.

As the changes in cigarette design were coming about, cigarette manufacturers' advertising and marketing efforts portrayed new-generation cigarettes as being lighter and safer, said Dr. Strauss. The August 2006 decision in the civil case of United States v. Phillip Morris et al underscored the industry's deception, he added.

In her 1,652-page decision, Judge Gladys Kessler wrote, "By 1953, Defendants recognized the need for concerted action to confront accumulating evidence of the serious consequences of smoking."

"While continuing to insist that there was no indications that cigarettes were unsafe, Defendants moved aggressively to market products which they implied were safe," Judge Kessler continued.

"Based on their sophisticated understanding of compensation . . . . Defendants internally recognized that low tar cigarettes are not less harmful than full-flavor cigarettes . . . . The terms 'Light' and 'Low Tar' as they are used by Defendants are essentially meaningless and arbitrary," Judge Kessler wrote.

The jurist went on to accuse the tobacco industry of engaging in deception to give consumers the impression that low-tar/light cigarettes were safer and increase sales of those brands. The deception occurred against a backdrop of increasing evidence of smoking's adverse health effects, she wrote.

Dr. Strauss concluded that, "While so-called 'low-tar' and 'light' cigarettes do not reduce lung cancer risk, their adoption appears to be responsible for the dramatic rise in adenocarcinoma of the lung."