Annual CT Detects Early-Stage Lung Cancers, Saves Lives
It has long been known that lung cancer is the number one cancer killer of
men and women. While smoking is the number one risk factor for lung cancer,
it would still be nice if we had an effective screening test. As with most
cancers, early-stage lung cancer is the most curable form of the disease. While
prevention is the ideal way to reduce mortality from lung cancer, early detection
and treatment is our next best bet. Good news has come from a recent report
from an ongoing 10 year study of 6,318 smokers: the Early Lung Cancer Action
Project (ELCAP) found that regular CT screening annually is an effective tool
for diagnosing early-stage lung cancer. If you're a smoker-or a former smoker-who
hasn't yet had a screening CT scan, you may want to add discussing this with
your physician to your list of things to do.
"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, MD, Ph.D., principal investigator of
the studies and professor of radiology and division chief of chest imaging at
New York Hospital/Cornell Medical Center in New York City. Dr. Henschke presented
these findings Dec. 1, 2003 at the annual meeting of the Radiological Society
of North America (RSNA).
Not only is lung cancer is the leading cause of cancer death among men and
women, more people will die from it than from breast, colon and prostate cancers
combined, according to the American Cancer Society. Lung cancer has no
clear early warning signs and a tumor may be the size of an apple by the time
it is detected, often once symptoms like shortness of breath, hoarseness, coughing
up blood, and unexplained weight loss have developed.
Stage I cancer is typically small (no larger than 10 millimeters in diameter)
and localized in the lungs without spreading to the lymph nodes. The average
cure rate for patients when Stage I lung cancer is removed is 60 percent to
70 percent, while the cure rate for more advanced types of lung cancer - Stage
II and later - is less than 5 percent, according to Dr. Henschke.
The ELCAP is a cohort study which was conducted from 1993-2003. It is a large
study that will issue several different reports focusing on different aspects
of lung cancer risks, detection and screening. In this study, multiple annual
CT screenings were performed on 2,968 high-risk subjects to determine the proportion
of lung cancers diagnosed on repeat CT screenings compared to those diagnosed
from symptoms or clinical examinations between the screenings. The study also
looked at the number of deaths due to lung cancer after long-term follow-up.
Cancers were classified as being either an annual repeat screening diagnosis
(findings on a low-dose CT scan 11 to 13 months after the last screening) or
as an interim diagnosis (symptoms appearing within 12 months after the last
screening). Among the 29 cases diagnosed, 28 were screening-diagnosed and one
was interim-diagnosed, indicating that annual screening was frequent enough
to diagnose early-stage lung cancer before a clinical diagnosis would have been
made.
Long-term follow-up of patients with screen-diagnosed lung cancer who underwent
surgery also showed a high cure rate. "Through these screenings we will
determine how many patients are cured," Dr. Henschke said. "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." Most importantly,
we hope that this information along with all the other information out there
about the dangers of smoking, will help to influence smokers to quit and non-smokers
not to start.
Created: 1/12/2004 - Donnica Moore, M.D.
