(The Hill) — Nearly 5 million additional Americans should be screened for lung cancer, according to an updated guideline released Wednesday by the American Cancer Society (ACS). 

The update marks the first change to screening recommendations in a decade. The group now recommends annual screening with low-dose computed tomography for men and women between the ages of 50 and 80 who currently smoke or formerly smoked, with a 20-pack-year history. 

A pack-year is equal to smoking one pack, or about 20 cigarettes, per day for a year. For example, someone who smoked two packs a day for 10 years has a 20-pack-year history, as well as someone who smoked one pack a day for 20 years. 

A computed tomography scan uses X-rays to make detailed images of a person’s chest, including the lungs. It can help find abnormal areas in the lungs that may be cancer before they start causing any symptoms.

The previous recommendation, from 2013, said screening should be for adults ages 55 to 74 with at least a 30-pack-year smoking history, who either currently smoke or quit smoking less than 15 years ago. 

Now, though, “for individuals who formerly smoked, the number of years since quitting is not an eligibility criterion to begin or to stop screening,” the organization wrote. 

While quitting smoking lowers the risk of lung cancer over time compared with continued smoking, the risk is still higher than among people who have never smoked, the ACS wrote. 

Lung cancer is one of the most common types of cancer in both men and women, and it accounts for 20 percent of all cancer deaths.  

The death rate has been declining sharply in recent years largely due to tobacco control efforts, but it is still extremely deadly.  

The ACS estimated nearly 240,000 new cases of lung cancer will be diagnosed, and about 127,000 people will die from the disease in 2023. Cigarette smoking accounts for approximately 80 percent of all cases. 

Many deaths from lung cancer could be prevented if people who qualify for lung cancer screening got tested every year, the ACS said.  

The ACS recommendation now aligns more closely with that of the U.S. Preventive Services Task Force (USPSTF), an independent panel of medical experts, which recommends annual low-dose computed tomography screening for lung cancer in adults aged 50 to 80 years who have a 20-pack-year smoking history. 

Because the task force endorsed the scans, most insurers must cover it without imposing cost-sharing on patients. However, the USPSTF recommendation only extends to people who currently smoke or have quit within the past 15 years.