Millions are missing out on lung cancer screening.

Millions are missing out on lung cancer screening.

Lung cancer patient Marcy Duncan

Marcy Duncan hadn't fully healed from her surgery for stage I breast cancer when she and her boyfriend met with her oncologist in the spring of 2022. She expected to discuss radiation and other next treatment steps. But her doctor raised a more serious concern, rolling his chair a bit closer to the couple before starting to speak.

After that, Duncan's memory is a bit hazy. Did he say that testing had found a mass, or did he mention the possibility of lung cancer specifically? She remembers hearing its size: 8 centimeters. But she pictured 8 inches instead. How, she wondered, could something so large even fit inside her lungs?

The room grew very quiet. "Thank God I had somebody with me," she says. "We were in shock — it was definitely shock."

The U.S. Preventive Services Task Force recommends that older adults who smoke and some former smokers get screened every year with low-dose computed tomography (CT). That recommendation has been in place for a decade. More than 14 million U.S. adults qualify. But only 5.8% of them got screened in 2021, American Lung Association data show.

The result: Many lung cancers are still caught as Duncan's was: essentially by chance, not by regular screening.

[Editor's update: The American Cancer Society has separate lung cancer screening guidelines. On Nov. 1, 2023, the Society updated its guidelines, saying that people who have ever had at least a 20 pack-year smoking history are eligible to get yearly low-dose lung CT screening, regardless of how long ago they quit smoking.]

Lung cancer kills more U.S. men and women than any other type of cancer: about 127,000 people each year. Too often, it's found too late.

That's what had happened to Duncan's father, who died at age 66. His lung cancer was as "big as a grapefruit" when it was discovered, Duncan says. Her oncologist had pressed Duncan to get the lung scan, in part because of her family history and also because she herself had smoked for decades.

Only 1 in 5 lung cancers are diagnosed before they've spread to the lymph nodes or beyond. Although treatments have improved, the odds are still best in the earliest stages.

Far more people get screened for other cancers. More than 70% of eligible adults, for instance, keep up with mammography and colon screening.

Why the lag? Cancer doctors and screening advocates blame a mix of reasons. The lung cancer guidelines are more complex than for breast or colon screening, which is based primarily on age. Some people don't live near a screening program. Or they don't understand the life-saving payoff. When a CT scan detects lung cancer in its early stages, 80% of people can expect to live at least 20 years, researchers reported last year.

Too often, though, people incorrectly view lung cancer through a fatal prism, says Timothy Mullett, MD, a University of Kentucky lung cancer surgeon who co-leads an effort to boost prevention and early detection throughout that state. "Why should I look for a disease that's only going to kill me?" he says some people may think.

Some current and former smokers feel a sense of guilt that they brought tobacco's harms on themselves, he says. "Obviously, that's not fair; that's not true. It's an addiction."

Other early detection tools may one day prove useful. Some researchers are working on so-called liquid biopsies, sophisticated blood tests that look for tumor DNA and other markers of cancer. Others have tapped into the ability of artificial intelligence (AI) to analyze massive databases of CT scans to better predict who might be more vulnerable to lung cancer.

But for now, getting an annual chest scan is the best way to catch these cancers early in smokers and former smokers, says Jacob Sands, MD, a volunteer spokesperson for the American Lung Association and a lung cancer physician at the Dana-Farber Cancer Institute in Boston. It's a quick test, and patients don't feel any discomfort, he says. "They lay on a table for 5 minutes and get a CAT scan, and they're done. And with that, we can substantially increase the likelihood of curing them of lung cancer if they have it."

Missed Opportunities

Duncan believes that she'd still be in the dark about her lung cancer if she hadn't been diagnosed with breast cancer last year.

She had put off getting her first mammogram until age 50, worried that it would painfully squeeze her breasts. But that test was easier than she had expected, and the lung scan was even easier. She lay down and placed her hands above her head, linking her fingers. As she slid through the scanner, she held her breath.

Even though she had smoked since her teen years, Duncan didn't have a smoker's cough. She didn't get short of breath. But that first scan, her doctor suggested, could be compared against future scans to catch any emerging signs of cancer.

The scariest part, she says, is that she nearly skipped the scan. Breast cancer treatment was stressful enough, says Duncan, who lives in Moreno Valley, CA. She preferred to skip the scrutiny and the lecture that she expected.

"I didn't think I would have lung cancer," she says. "I just thought they would be like, 'Your lungs look like crap.' That they were going to say, 'Look what you did to your lungs.'" But a week or so after her breast surgery, Duncan decided to get the scan, eager to put all medical testing behind her.

In 2021, the U.S. Preventive Services Task Force lowered the minimum age to start CT scans to age 50, down from 55. Adults ages 50 to 80 may be candidates if they smoke or have quit within the last 15 years. But they also must calculate their smoking history. The American Lung Association provides an online quiz to help with the math.

Lung cancer screening is recommended for more than 14 million U.S. adults. Only 5.8% of them got screened in 2021.

It can be difficult for primary care physicians to get an accurate smoking history, says Gerard Silvestri, MD, MS, a lung cancer pulmonologist and researcher at the Medical University of South Carolina in Charleston. A patient's smoking habits may change from year to year.

"People underestimate how much they smoke all the time," he says. Too often, former smokers aren't even asked. If someone quit 10 years ago, he says, "it's not top of mind for the patient or the doctor."

To best detect early cancer, lung screening must be repeated annually. But Silvestri's research, published in 2022, shows that only 22.3% of patients came back the next year. Just one-third of patients returned within 2 years.

Even if lung cancer isn't found, CT scans can show other possible medical problems, which may require more testing — and prompt some anxiety. The imaging shows a potentially significant finding roughly one-third of the time across three screening exams, a recent analysis shows.

Of those concerns, emphysema was the most common, found 43% of the time. Another common finding, identified in 12.1% of cases, was calcium buildup in the heart's main arteries. Called coronary artery calcification, it is linked to an increased risk for heart problems, including heart attacks.

Flagging these conditions sooner can help patients, says Caroline Chiles, MD, a study author and a radiology professor at Wake Forest University School of Medicine in Winston-Salem, NC. People with calcifications can start preventive medication, such as a statin, she says. Those with emphysema can be encouraged to quit smoking.

"The knowing is better than the not knowing."

– Marcy Duncan

Most small abnormal areas in the lung, called nodules, won't be malignant, Chiles stresses. They can be caused by old infections, scar tissue, and other reasons. What steps doctors advise next will depend upon the nodule's size and other factors, she says. They may ask the patient to return for their next scan in a year or sometimes sooner, such as in 6 months. "If it hasn't changed in 6 months, that's very reassuring," she says. If a lung nodule is large enough, doctors recommend a biopsy.

Tapping AI

Lecia V. Sequist, MD, MPH, a lung cancer specialist at Boston's Massachusetts General Hospital, is working to harness artificial intelligence (AI) to alert people who are more likely to develop lung cancer, even before a CT scan can show it. She's working on an AI tool called Sybil, a joint venture of Massachusetts General and the Massachusetts Institute of Technology (MIT). The tool has been trained on chest CT scans from the National Lung Screening Trial, the study on which the screening guidelines are based.

The next step for the research, which hasn't started enrolling patients yet, is to learn how well Sybil predicts lung cancer not just in adults who smoke, but also those who quit decades ago or have never lit up, Sequist says. If the AI tool, or something similar, one day proves better at flagging lung cancer risk, then all adults could be screened at least once, she says. Then they could be advised whether and how often they should return.

Adults who quit more than 15 years ago aren't eligible for screening now, Sequist notes. Neither are people who never smoked, even though they account for 10% to 20% of U.S. cases that are diagnosed each year. The main criteria right now is smoking history, "which is a crude tool," Sequist says. "It also can be stigmatizing."

'Just Do It'

Flora McCoy-Greene quit smoking at age 39. That year, her husband had started to complain about back pain. His lung cancer, by the time he was diagnosed, was stage IV.

"That was the day that I threw my cigarettes in the trash," says McCoy-Greene, a retired speech and language therapist.

Flora McCoy-Greene

In 2019, she was getting ready to move from Cape Cod, MA, to Japan to teach at an international school. The job required a physical, including a chest X-ray. She had no symptoms.

A nurse practitioner sat her down and shared the results. "She said that she couldn't authorize me to go to Japan," McCoy-Greene says. "There was something on my lung that looked like a malignancy."

After radiation, chemotherapy, and immunotherapy, McCoy-Greene, now 71 and living in Palm Bay, FL, is cancer-free.

Once Duncan got her bearings, she decided to focus on the positive: that they found her lung cancer before she had any symptoms. Like McCoy-Green, she got chemo, radiation, and immunotherapy. "It's too early to say that I'm in remission, but everything is good health-wise," she says.

Duncan will tell anyone who qualifies, including her own sister, to get screened. (Her sister's scan was cancer-free.) "Stop beating yourself up over your smoking and just do it," she says. "The knowing is better than the not knowing. If I waited until I had symptoms, my gosh, I wouldn't be alive today, I don't think."