Women Smokers' Lung Cancer Risk Twice That of Men
WASHINGTON, D.C. -- December 19, 2003 -- Women have twice the risk of developing lung cancer from smoking than do men, according to a research paper presented recently at the annual Radiological Society of North America conference. However, the reason for the gender difference is not yet clear, according to one of the authors (Press Release, December 1, 2003). The study also found that lung cancer risk increases after the age of 50 and depends upon the amount of tobacco use, although these factors did not account for the varying results between females and males.
A total of 2,968 men and women took part in the 10-year study, which used computed tomography (CT) scans and other procedures to detect 113 lung cancers. A CT scan is a process that uses a computer to combine multiple x-ray images into cross-sections. Doctors consider CT scans to be more sensitive than standard x-rays alone.
CT Scans Useful in Detecting Early Lung Cancer
The research was part of the Early Lung Cancer Action Project (ELCAP), a study to see if annual CT screenings of smokers can save lives by detecting lung cancer in its early stages. Researchers looked at the number of cancers diagnosed at repeated yearly CT screenings as compared to those diagnosed based on symptoms occurring between the annual screenings (see Lung Cancers Diagnosed under Annual Repeat CT Screening and New York Early Lung Cancer Project). They found that yearly CT scans were useful in diagnosing early-stage lung cancer in smokers and therefore reducing death rates.
"More than 80 percent of the diagnosed lung cancers we found in initial and annual repeat CT screenings were Stage I--the most curable form of lung cancer," said Claudia I. Henschke, M.D., Ph.D., principal investigator and division chief of chest imaging at New York Hospital/Cornell Medical Center in New York City (Press Release, December 1, 2003). "...Through these screenings we will determine how many patients are cured. Depending on the resulting long-term follow-up, we hope that CT screening will be made widely available to high-risk smokers and former smokers."
Stage I lung cancer is small and has not spread to the lymph nodes or organs (American Cancer Society, non-small cell cancer staging). Based on older statistics, the American Cancer Society gives a 5-year survival rate of 47% for non-small cell lung cancer patients with Stage I cancer, but says that the survival rate may actually be higher today. According to Dr. Henschke. the average cure rate for patients when Stage I lung cancer is removed by surgery is 60 percent to 70 percent, while the cure rate for more advanced lung cancer stages is less than 5 percent.
Tobacco Use and Lung Cancer Risks
Nearly one in every five deaths in the United States is smoking-related, and tobacco use results in annual medical costs of more than $75 billion (Tobacco Information and Prevention Source, Centers for Disease Control). Lung cancer accounts for about 124,813 deaths per year in the United States, based on statistics from 1995 through 1999. (Targeting Tobacco Use, Centers for Disease Control). It is the leading cause of cancer death, and more people die of lung cancer than of colon, breast, and prostate cancers combined.