Low-Dose CT Screening Benefits Never-Smokers, Too

Low-dose CT (LDCT) screening for lung cancer does not benefit smokers alone. It can also be used to successfully screen patients who have never smoked for the disease.

During the International Association for the Study of Lung Cancer 2021 World Conference this weekend, investigators from Taiwan revealed data that shows LDCT screening can identify the presence of lung cancer in individuals who have never actively smoked, but who are still at high-risk for the disease.

Existing studies, including the National Lung Cancer Screening Trial (NLCST) and NELSON Trial have already demonstrated LDCT’s role with smokers, but with 10 percent-to-15 percent of lung cancer cases developing in non-smokers, being able to detect disease in this group is critical.

Given that lung cancer is Taiwan’s leading cause of cancer mortality – and 53 percent of people who die never smoked – investigators, led by Pan Chyr Yang, M.D., Ph.D., distinguished professor from National Taiwan College of Medicine who has a specific interest in lung cancer genomics, launched the Taiwan Lung Cancer Screening for Never Smoker Trial (TALENT). This study not only tested LDCT efficacy with never-smokers, but its goal is to create an effective screening strategy and risk-prediction model to identify high-risk individuals who could benefit from screening.

“The study revealed that LDCT screening for lung cancer in never-smoker with high risk may be feasible, which is very important to all who are fighting against lung cancer, [considering] the increasing global threat for lung cancer in never-smoker,” he said. “Most importantly, the study showed that family history of lung cancer may increase the risk of lung cancer.”

For the study, Yang’s team enrolled 12,011 participants who had at least one lung-cancer risk factor, including family history within third-degree relations, passive smoking exposure, tuberculosis or chronic obstructive pulmonary disease, cooking index of 110 or greater, and no ventilation during cooking. Patients, who were between ages 55 and 75, were enrolled between February 2015 and July 2019.

Of the participants, Yang said, 6,009 (50 percent) had a family lung cancer history. Based on screening, 2,094 (17.4 percent) were considered positive, leading to 395 (3.3 percent) lung biopsies or surgeries. Overall, 313 patients (2.6 percent) received lung cancer diagnoses – 255 (2.1 percent) of whom had invasive disease. Nearly all diagnoses – 96.5 percent – were for stage 1 disease, and all but one was adenocarcinoma. Benign lung disease or another type of cancer accounted for the remaining 81 patients.

According to their findings, lung cancer prevalence was 3.2 percent and 2.0 percent in patients with and without lung cancer family history, respectively. In addition, invasive lung cancer prevalence was 2.6 percent and 1.6 percent, respectively, and the risk elevated with the number of first-degree relatives with lung cancer that a patient had:

• 0: 2.0 percent
• 1: 3.1 percent
• 2: 4.0 percent
• 3: 6.7 percent
• 4: 9.1 percent

These findings, Yang said, were encouraging.

“Most importantly, 96.5 percent [of] patients were stage 0 or 1, [and] were potentially curable by surgery,” he explained. “Our study also revealed the high risk of family history, especially those [participants] with a first-degree family history of lung cancer.”

Using these results, he said his team is working to create a risk-score predictor that incorporates family history, as well as genetic and environmental factors, to pinpoint high-risk, never-smoker patients who might benefit from LDCT screening.

“We hope the screening program can benefit patients suffering from lung cancer especially in those countries with high incidence of lung cancer in never smoker,” he said.

Ultimately, he said, that work should lead to a screening protocol that can be implemented nationwide.

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