These women were diagnosed with lung cancer. They weren’t eligible for screening.

In 2024, Kara Goodwin started feeling a pain in her arm and shoulder that wouldn’t go away.

She was diagnosed with bicep tendinitis and frozen shoulder. Doctors thought the resident of Brooklyn, New York, who has run multiple marathons, had an overuse injury from her active lifestyle.

Two months later, when the pain hadn’t gone away, Goodwin got an MRI. “They could visibly see the giant tumor that was shattering my humerus bone from the inside out,” she said.

Goodwin, now 39, was diagnosed with stage 4 lung cancer that had spread to her bones. It was “quite shocking as a marathon runner,” she said. “I have no family history of cancer,” she added.

Goodwin’s cancer, while treatable, can’t be cured. The treatments will keep the cancer at bay but eventually, she said, they’ll most likely stop working.

Lung cancer is more curable when it’s found at an earlier stage, according to the American Lung Association.

For Goodwin, it’s unlikely that would’ve happened: Lung cancer screening isn’t recommended for people her age, nor is it recommended for people who were never smokers.

The current guidelines, from the U.S. Preventive Services Task Force, say that people ages 50 to 80 who smoked a pack a day for 20 years and still smoke or have quit in the past 15 years should get a yearly scan to screen for lung cancer.

But up to 20% of lung cancer cases are diagnosed in people who never smoked or used any other form of tobacco, according to the American Cancer Society.

A new study, published Thursday in JAMA Network Open, suggests that the guidelines are missing the majority of lung cancer cases.

People still think of lung cancer as a disease that only affects older men and lifetime smokers, even though it’s becoming more common in younger women and people who never smoked, said lead study author Dr. Ankit Bharat, executive director of the Northwestern Medicine Canning Thoracic Institute in Chicago. “Every day, we are seeing patients who’ve never smoked, who may have had passive smoking exposure, they’re coming with advanced lung cancer, and then it’s not curable.”

Bharat’s research found that 65% of lung cancer patients at Northwestern didn’t qualify for screening based on the current guidelines. Women, Asian Americans and nonsmokers diagnosed with lung cancer were likelier to be ineligible for screening, the study found. (Another study, published Wednesday in the Journal of the American Medical Association, found that even among people eligible for screening, less than 20% were up to date.)

Lung cancer is the deadliest cancer in the United States, according to the ACS. At the same time, death rates for the disease have fallen significantly in recent decades, largely because of reductions in smoking.

“Smoking-related lung cancer incidence is decreasing, but as that decreases, then a higher proportion of people that get lung cancer have these other reasons for getting lung cancer,” said Dr. Helena Yu, a thoracic medical oncologist at Memorial Sloan Kettering Cancer Center in New York City.

Most of the patients she sees with lung cancer have stopped smoking decades ago, or were light smokers and wouldn’t qualify for screening. “We probably should be screening a larger population, because we’re finding it if you look at these different groups,” she said.

Even trickier are the cases in her patients who never smoked, including Goodwin.

“There aren’t clear environmental factors, we’re not seeing that it’s radon or secondhand smoke or anything specific that’s leading to these mutation-driven lung cancers,” Yu said. “But there are probably factors that we don’t know in our modern-era world that are affecting both lung cancer but also other cancers, like GI cancers and other cancers that we’re seeing on the rise.”

In Bharat’s study, researchers modeled how many cases they would’ve caught by expanding the screening criteria. If the guidelines included people who smoked a pack a day for 10 years and were ages 40 to 85, they could increase the detection rate to 62%. If they used a universal approach, screening all adults in that age group regardless of smoking status, they would’ve caught 94% of cancers.

“Having such a universal program would not only capture a majority of these patients, but we would be able to detect most of these patients at an earlier stage, which would dramatically improve the long-term survival as a whole population, with regards to lung cancer,” Bharat said.

Danielle Hoeg, of Chicago, was diagnosed with lung cancer last year, when she was 43. She had never smoked.

“I just didn’t believe it,” Hoeg said.

Her cancer was caught early — at stage 1 — on an unrelated MRI scan. She had no symptoms, such as a persistent cough or chest pain. Because the tumor was found at an early stage, she was able to have it surgically removed and didn’t require any additional treatment.

“I’m at the point now where I probably would, if I hadn’t found it, probably be dead by now,” she said.

MRIs, however, aren’t the standard tool used to look for lung cancer. Instead, screenings are done using a low-dose CT scan, a type of X-ray that takes images of the lungs using low amounts of radiation. One concern with universal screening is that patients could be exposed to unnecessary radiation. Another concern is false positives.

“The screening guidelines, as they currently stand, are heavily focused on smoking history and age,” said Dr. Jhanelle Gray, a thoracic medical oncologist at Moffitt Cancer Center in Tampa, Florida. This leaves out “some groups who don’t fit that criteria and are still at risk and so when you look at the guidelines, we need to look at expanding the criteria to reach more high-risk patients.”

“It’s kind of easier said than done,” Gray added. “We also need the research to prove that this is a value.”

Dr. Nicole Geissen, a thoracic surgeon at Rush University Medical Center in Chicago, said doctors should focus on increasing screening in people who currently qualify.

“Yes, there needs to be ongoing discussions about making the criteria less stringent and more easily understood by both patients and primary care,” Geissen said. “But until that happens, we need to really focus on how do we get the other 80% of people that actually qualify for the current guidelines to get screened.”

Bharat is now enrolling adults in a large clinical trial at Northwestern and screening them for lung cancer. At the end of the trial, he hopes to find the patient population that would benefit the most from screening.

Yu said that one of the challenges is a lack of funding for lung cancer research.

“Lung cancer is the No. 1 cancer killer, more than breast cancer, colon cancer, prostate cancer combined every year, but the funding for research is the lowest for lung cancer, and that’s partly because it’s survivors that are the biggest fundraisers,” she said. “Unfortunately, most people don’t survive a diagnosis of lung cancer.”

This article was originally published on NBCNews.com