A seven-year national study including 2,400 Hawaii volunteers is expected to tell researchers next year whether screening can reduce lung cancer deaths.

The findings could result in broader insurance coverage for such tests.

Drs. Lance Yokochi and Peter Balkin of the Pacific Health Research Institute in Honolulu have led Hawaii's participation in the National Lung Screening Trial since 2002. The institute recently was awarded $2.8 million by the National Cancer Institute to continue the research for another two years.

More than 1,100 Hawaii residents die annually from lung cancer, according to American Lung Association statistics.

The lung cancer study is a spinoff from a Prostate, Lung, Colorectal and Ovarian Cancer Screening Study that's following 10,800 Hawaii participants and 155,000 nationally.

Initially, smokers and nonsmokers were screened for lung cancer as part of that study, said Yokochi, an occupational medicine specialist and principal investigator for the broad cancer trial at the institute.

But it was decided to do a separate study looking only at smokers and compare spiral computerized tomography with chest X-rays for screening, he said.

Participants include current and previous smokers, ages 55 to 74, with a 30-year, pack-a-day history of smoking, Yokochi said.

Balkin, a radiologist, said each participant was screened in three consecutive years—half with CT and half with chest X-ray screening.

He said data are being compiled and pooled with nine other study sites to try to determine if CT or X-ray screening is viable to help decrease lung cancer mortality in smokers or prior smokers.

Balkin said about 15 percent of lung cancers occur in nonsmokers, but the incidence is so low it probably wouldn't be cost-effective to screen for it in that group.

He said most insurance carriers don't cover CT or X-ray screening for lung cancer detection. But if the study shows a significant benefit from screening for lowering cancer mortality, he said, “;My guess is all major carriers, including Medicare, would make their policy fit with the results of the study.”;

No one was accepted in the study with symptoms of lung cancer, Balkin said, “;but we do know some have developed symptoms, some have developed cancer and some have died.”;

“;Did more die in the CT group or the X-ray group? If there is a significant difference between the two, we will have our answer.”;

Yokochi said the CT scan “;is a glorified chest X-ray in a sense,”; but it does a lot of scans because it's computerized and it tends to pick up smaller cancers missed by chest X-rays. It can detect tumors under 0.4 inches in diameter while chest X-rays detect tumors 0.4 to 0.8 inches in size.

However, a prior study of chest X-rays showed no impact on mortality from picking up cancer earlier, Yokochi noted.

“;We're getting much better resolution in terms of chest X-ray alone,”; he said.

Low dosages of radiation were used in the study but radiation does increase risk, he pointed out.

Participants were referred to smoking-cessation programs if they wanted to quit smoking.

Dr. Bruce Stevenson, Pacific Health Research Institute chief executive officer, said the new research funding allows the institute “;to continue addressing a major medical problem that afflicts hundreds of thousands of people. ... The PHRI team is privileged to be part of this vital cancer research study that may save lives.”;