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Early screening could reduce lung cancer deaths

Updated Wed. Oct. 25 2006 6:35 PM ET

CTV.ca News Staff

A new study provides compelling evidence that early screening for lung
cancer among high-risk groups could dramatically reduce lung cancer death
rates.

The results, which are to be published in the October 26 edition of the
New England Journal of Medicine, find that lung cancer can be detected at
its very earliest stage in 85 per cent of patients using annual low-dose
CT screening.

The Toronto arm of the study screened 2,300 former smokers, and found 32
cases of lung cancer.

CT, or computed tomography, scans involve technology that views the lungs
and surrounding tissue at different angles and can spot growths that are
small as a grain of rice.

When detection is followed by prompt surgical removal, the 10-year
survival rate is 92 per cent, according to results from the largest
long-term study to determine the usefulness of annual CT screening.

Elsa Poitras was a heavy smoker for 25 years. And even though she quit the
habit 17 years ago, concern she was at risk for lung cancer led her to
take a CT screening. She was right: the scan showed a two-centimetre
tumour, undetectable on a chest X-ray machine.

Doctors removed the tumour in January and Poitras needs no further
treatment.

"I owe my life to that screening study," Poitras told CTV News.

In the absence of screening, the vast majority of lung cancers are
diagnosed in later stages, when it can no longer be cured.

"We believe this study provides compelling evidence that CT screening for
lung cancer offers new hope for millions of people at risk for this
disease and could dramatically reverse lung cancer death rates," said lead
author Dr. Claudia Henschke, radiology professor and chief of chest
imaging at New York-Presbyterian/Weill Cornell Medical Center.

Among the more than 31,500 people examined in the study, CT scans detected
484 people who were diagnosed with lung cancer, 412 of whom were Stage I.

Overall, the estimated 10-year survival rate for the 484 participants with
lung cancer was 80 per cent.

Remarkable advances allow doctors to use word 'cure'

Stage 1 lung cancer is the only stage at which curing the patient of
cancer is highly likely, according to the researchers.

"Those Stage I diagnoses represented cases of genuine cancer," said Dr.
Olli S. Miettinen, McGill professor in the Faculty of Medicine, Department
of Epidemiology, Biostatistics and Occupational Health, and Department of
Medicine.

"All of them were confirmed by a panel of internationally recognized
experts on lung pathology; 95 per cent of the lesions were already
invasive; and in all of the eight instances in which treatment was
refused, the patient died of lung cancer within five years," Miettinen,
one of the researchers who guided the study, said in a written statement.

The participants were 40 years of age and older and at risk for lung
cancer as a result of a history of cigarette smoking, occupational
exposure (to asbestos, beryllium, uranium or radon), or exposure to
secondhand smoke.

There have been remarkable advances in CT scanners since the early 1990s,
which allow for the detection of lung cancer in cases that it was
previously near-impossible to diagnose.

In the past, CT scans yielded only 30 images, where current technology
captures more than 600 images.

Cost could emerge to be an issue, as the charge for a low-dose CT
screening ranges from US$200 to $300, but doctors say treatment for the
earliest stage of lung cancer is less than half the cost of late-stage
treatment.

The International Early Lung Cancer Action Project, which was launched by
a team of researchers at New York-Presbyterian Hospital/Weill Cornell
Medical Center in 1993, has expanded into a collaboration of 38
institutions in seven countries.

With files from CTV's medical specialists, Avis Favaro & Elizabeth St.
Philip