FRIDAY, Jan. 11 (HealthDay News) -- New recommendations from the American Cancer Society say that older current or former heavy smokers may want to consider low-dose CT scans to help screen for lung cancer.

Specifically, that includes those aged 55 to 74 with a 30 pack-year smoking history who still smoke or who had quit within the past 15 years. Pack-years are a calculation made by multiplying the number of packs of cigarettes smoked a day by the number of years of smoking.

"Even with screening, lung cancer would remain the most lethal cancer," said Dr. Norman Edelman, chief medical officer at the American Lung Association. He noted the cancer society guidelines are similar to the ones from the lung association.

The new recommendation follows on the results of a major U.S. National Cancer Institute study, published in 2010 in Radiology, that found that annual CT screening for lung cancer for older current or former smokers cut their death rate by 20 percent.

Edelman stressed that the study does nothing to change the fact that smoking prevention and cessation remain the most important public health challenge there is.

"Screening is not a way to make smoking safe from cancer deaths, and certainly does nothing to prevent smoking-related deaths from chronic obstructive pulmonary disease and heart disease," he added.

The cancer society recommendations also emphasize smoking cessation counseling as a high priority and stress that CT screening is not an alternative to quitting smoking.

CT screening should only be done after a discussion between patients and their doctors so people fully understand the benefits, limitations and risks of screening. In addition, screening should only be done by someone experienced in low-dose CT lung cancer screening, the cancer society stressed.

These new guidelines were published in the Jan. 11 online edition of CA: A Cancer Journal for Clinicians.

Results from the 2010 trial indicated that deaths from lung cancer in specific high-risk groups could be reduced by annual CT screening. "These findings indicate that the adoption of lung cancer screening could save many lives," the cancer society concluded.

As with any guidelines, however, recommendations may change over time as more people are screened and new data are analyzed.

Despite the lifesaving benefits of screening, there are still some harms and limitations. Among these are missed cancers, anxiety caused by abnormal results, the need for additional tests and biopsies, investigation of other findings not related to lung cancer and exposure to radiation from repeated testing, the cancer society noted.

The cancer society hopes these guidelines will help inform people at high risk for lung cancer about finding lung cancer early, when it has the best chance of being treated.

Many questions remain, Edelman noted.

"The most prominent is which groups who have lower risks of lung cancer than the group studied will benefit from screening. That is, at what point, in terms of risk factors, will the risks of radiation and biopsy of benign tumors outweigh the risk of cancer," he said.

There are not only important medical questions, but also economic ones since issues of increased costs and insurance coverage are yet to be addressed, Edelman said.

Another expert, Dr. Michael Unger, a doctor with Allied Healthcare Associates in Northbrook, Ill., said that "it has been proven repeatedly that mere chest X-ray screening is insufficient to provide any benefit to survival."

That said, there have been several studies showing a survival benefit by screening high-risk individuals with low dose CT scans, he added.

"Whether or not such screening recommendations are accepted by Medicare and private insurance companies will eventually determine how broadly these recommendations are implemented," Unger said. "I believe only a small number would pay for such a scan out of their own pocket."

More information

For more on lung cancer, visit the American Cancer Society.