CT scans show promise for lung cancer screening

A heavy smoker for more than 45 years, Fernando Sandoval quit cold turkey after a CT scan revealed he had a tumor in his lung.  Nine years ago Sandoval was one of the first people to participate in a clinical trial at UCLA to determine whether  a low-dose CT scan can be used as a possible screening tool for the deadliest cancer. Final results from this clinical trial, which enrolled more than 53,000 people at 33 different sites, found low-dose CT screening reduces the number of lung cancer deaths in high risk smokers by 20%.

Sandoval received a regular chest X-ray in 2002 and was told his lungs looked like those of a 40-year-old, even though he had already passed his 60th birthday.
But his wife didn't believe the X-rays because she knew he smoked too much, so she urged him to participate in the clinical trial.

"I owe my life to wife and UCLA," says Sandoval. He was chosen to get his lungs screened with a CT scan even though he had no symptoms of illness. Two weeks later he was told doctors had found a nodule on the bottom lobe of his left lung. "I had surgery and after the surgery I was told we caught it in time."  Sandoval says the cancer hadn't spread and he didn't even need chemotherapy.

Early results from this study were first published last November, when the trial was stopped ahead of schedule because the results were so good.

"This is probably the most important thing to happen in lung cancer in a decade," says Dr. Bruce Johnson, who has been treating lung cancer patients for a long time at the Dana-Farber Cancer Institute in Boston. The study results were published in the New England Journal of Medicine on Wednesday.

"I believe that this is not only the best study done on lung cancer mortality, but one of the best studies on cancer screening ever done," says Dr. Otis Brawley, Chief Medical Officer for the American Cancer Society.

Lung cancer is the No. 1 cancer killer in men and women worldwide, yet there's no good way to screen for it.

Dr. Denise Aberle says she believes that since the death rates and overall complication rates were very low, these study results will eventually lead to screening guidelines for lung cancer. She is the national principal researcher for 23 of the 33 testing sites in this trial and a researcher with UCLA’s Jonsson Comprehensive Cancer Center, where Sandoval's cancer was found. "[The study] is the best we could come up with since 1964 when the surgeon general first announced the relationship between cigarette smoking and lung cancer," Aberle says.

Aberle, along with Johnson, Brawley and the study authors acknowledge that the study has some limitations. The people who received CT scans were more likely to have a false positive, which means something was identified that later did not turn out to be cancer. Overdiagnosis is also a concern, meaning some cancers were found "that never would have become symptomatic," according to the study.

Cost also is an issue. While an X-ray is about $50 dollars, the average cost of a spiral CT scan is  $300-$400, says Brawley. "But, the average cost of an abnormal spiral CT is about $40,000 to $50,000," he adds. That's because the patient will need surgery and further testing to see if what was found is really cancer.

But the screening is not perfect. In the study, 16 people who had the CT scans died, 10 of whom had cancer and 6 of whom did not. But the overall death rate in this group in the study was very low, about 1% says Aberle. "The [mortality] data for the general population is 4%," she says, which is why she believes the risk-to-benefit ratio is favorable.

Johnson, who is a oard member of the American Society of Clinical Oncologists, agrees. He points to the fact that 20% of the people screened didn't just live longer, but were probably cured of lung cancer because it was detected early.

He says this study shows that "you have to screen between 200-300 to reduce one death in lung cancer," which Johnson says "compares favorably to how mammograms work for breast cancer."

Johnson along with the study authors and the other experts agree there is a much better way to significantly reduce your risk of dying from lung cancer:  If you aren't smoking –  don't start; if you are smoking – quit.

One thing the cancer society, ASCO and other public health officials will have to grapple with is who should be screened and how to pay for it. This would not be something everyone ought to be screened for, given the limitations of the study. However, heavy smokers and those who quit less than 15 years ago who are between the ages of 55 and 74, just as the 53,000 who participated in the trial, could the be best candidates for lung cancer screening with a CT scan, based on these study results, experts believe.