Smokers' lung cancer risk identified in CT screening study

November 29, 2004

CHICAGO - For the first time, researchers can predict the lung cancer risk for social smokers as well as habitual smokers.

Data presented today at the annual meeting of the Radiological Society of North America (RSNA) showed that a social smoker age 50 or older has a risk for developing lung cancer similar to that of a smoker under age 50 who smoked three packs a day for 20 years.

Claudia I. Henschke, Ph.D., M.D., is the principal investigator of the International Early Lung Cancer Action Project (I-ELCAP), the largest study ever undertaken on whether annual screening by computed tomography (CT) can prevent deaths from lung cancer. I-ELCAP numbers were derived from the screenings of 27,701 men and women, some starting in 1993 at 35 international institutions.

"Based on our data, we can now predict, by age, by how much has been smoked or when a smoker has quit, what is the likelihood of developing lung cancer," said Dr. Henschke, a professor of radiology and division chief of chest imaging at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York City.

"Annual CT screening identifies a high percentage of Stage I diagnoses of lung cancer, the most curable form of lung cancer," Dr. Henschke said. "Our study found that deaths from Stage I lung cancer were surprisingly low after surgery, but only if treatment is pursued. Delaying treatment by more than six months resulted in increased tumor disease and often a higher stage of the disease."

Smokers should consult their doctors to determine at what age CT screening should begin, but this data provides the basis for such recommendations. With annual screening, there is a 76-78 percent chance of a smoker's lung cancer being cured, Dr. Henschke said. Without screening, the probability for cure falls to 5-10 percent.

I-ELCAP data also showed that, regardless of a smoker's age or how much has been smoked, the risk for developing lung cancer does not decline appreciably until 20 years after kicking the habit. "It starts decreasing slowly for the first 19 years after quitting, then drops to half by 20 years, although it always remains higher than in those who never smoked," Dr. Henschke said.

Lung cancer remains the major cause of cancer death in both men and women, killing more people than breast, prostate and colon cancers combined, according to the American Cancer Society.

The I-ELCAP study found that lung cancer develops in twice as many smokers age 50-74 (15 for every 1,000) than in smokers under 50 (6 per 1,000).

The number of smokers developing lung cancer also increased by the total number of cigarettes smoked: 28 smokers per 1,000 were found to have lung cancer if they smoked three packs a day for 20 years or more, compared with 16 smokers per 1,000 who smoked three packs a day for 10-20 years.

Variances in lung cancer rates were marginal between smokers with a pack-a-day habit for 10 years (6 per 1,000) and smokers who consumed two packs a day for 10 to 15 years (7 per 1,000).

Co-authors of the I-ELCAP study are Shusuke Sone, M.D., Steven Markowitz, M.D., Karl Klingler, M.D., Melvyn Tockman, M.D., Dorith Shaham, M.D., Matthew Rifkin, M.D., Javier Zulueta Frances, M.D., Samuel Kopel, M.D., David Naidich, M.D., Donald L. Klippenstein, M.D., Kimball Whitehouse Rice, M.D., Leslie Kohman, M.D., Arfa Khan, M.D., John H. M. Austin, M.D., Michael Smith, M.D., Salvatore Giunta, M.D., David D. Mendelson, M.D., Thomas Bauer, M.D., Robert Heelan, M.D., Nathaniel Berlin, M.D., Heidi Roberts, M.D., Shari-Lynn Odzer, M.D., Peter H. Wiernik, M.D., Davood Vafai, M.D., Ray Daniel, M.D., Harvey Pass, M.D., David Mullen, M.D., Michael Kalafer, M.D., Fred W. Grannis, M.D., Xueguo Liu, M.D., Barry Sheppard, M.D., Barry Ellis Mantell, M.D., David Gordon, M.D, Anthony Reeves, Ph.D., and David Yankelevitz, M.D.
-end-
Note: Copies of RSNA 2004 news releases and electronic images will be available online at RSNA.org/press04 beginning Monday, Nov. 29.

RSNA is an association of more than 37,000 radiologists, radiation oncologists and related scientists committed to promoting excellence in radiology through education and by fostering research, with the ultimate goal of improving patient care. The Society is based in Oak Brook, Ill.

Editor's note: The data in these releases may differ from those in the printed abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at between Nov. 27 and Dec. 3 312-949-3233.

Radiological Society of North America

Related Lung Cancer Articles from Brightsurf:

State-level lung cancer screening rates not aligned with lung cancer burden in the US
A new study reports that state-level lung cancer screening rates were not aligned with lung cancer burden.

The lung microbiome may affect lung cancer pathogenesis and prognosis
Enrichment of the lungs with oral commensal microbes was associated with advanced stage disease, worse prognosis, and tumor progression in patients with lung cancer, according to results from a study published in Cancer Discovery, a journal of the American Association for Cancer Research.

New analysis finds lung cancer screening reduces rates of lung cancer-specific death
Low-dose CT screening methods may prevent one death per 250 at-risk adults screened, according to a meta-analysis of eight randomized controlled clinical trials of lung cancer screening.

'Social smokers' face disproportionate risk of death from lung disease and lung cancer
'Social smokers' are more than twice as likely to die of lung disease and more than eight times as likely to die of lung cancer than non-smokers, according to research presented at the European Respiratory Society International Congress.

Lung cancer therapy may improve outcomes of metastatic brain cancer
A medication commonly used to treat non-small cell lung cancer that has spread, or metastasized, may have benefits for patients with metastatic brain cancers, suggests a new review and analysis led by researchers at St.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Lung transplant patients face elevated lung cancer risk
In an American Journal of Transplantation study, lung cancer risk was increased after lung transplantation, especially in the native (non-transplanted) lung of single lung transplant recipients.

Proposed cancer treatment may boost lung cancer stem cells, study warns
Epigenetic therapies -- targeting enzymes that alter what genes are turned on or off in a cell -- are of growing interest in the cancer field as a way of making a cancer less aggressive or less malignant.

Are you at risk for lung cancer?
This question isn't only for people who've smoked a lot.

Read More: Lung Cancer News and Lung Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.