Lung cancer screening feasible for Asian women who don’t smoke

Lung cancer screening with low-dose computed tomography (LDCT) may be offered to nonsmoking Asian women, with data from the Female Asian Nonsmoker Screening Study (FANSS) showing that screening yields an invasive lung adenocarcinoma detection rate of 1.5 percent.

The data, which was presented at WCLC 2023, was based on 201 women (mean age 56.6 years, 89 percent Chinese) in the US who had never smoked or smoked <100 cigarettes in one’s lifetime and identified as from Asian descent. Of these women, 41 percent had a family history of lung cancer, 47 percent had passive smoke exposure, and 19 percent had World Trade Center dust exposure (ie, being in the dust or dust cloud on 9/11). [Shum E, et al, WCLC 2023]

Baseline LDCT scans of the chest were read as Lung-RADS 1 or 2 for the majority of the participants (43.3 percent and 49.8 percent, respectively). Meanwhile, 13 participants had Lung-RADS 3 (3.0 percent) or 4 (3.5 percent). Lung cancer was found in three participants (1.5 percent), two of whom were in stage IIB and the other one was in stage IIIC.

Radiographic presentations varied among the three participants with lung cancer and included large solid masses and multiple subcentimetre ground glass opacities, reported Dr Elaine Shum, the lead author of the study and an oncologist at NYU Langone Perlmutter Cancer Center, New York, New York, US.

“Of note, all three of them did not have a family history of lung cancer. But all of them were surgically resected and found to have an EGFR mutation and, as such, were eligible in receiving adjuvant osimertinib,” per ADAURA, Shum said. [N Engl J Med 2023;389:137-147]

Cancer detection with LDCT in other trials

The lung cancer detection rate in FANSS was comparable with that in the Taiwan Lung Cancer Screening for Never Smoker Trial (TALENT; 1.52 percent for invasive adenocarcinoma) and higher than that in the National Lung Screening Trial (NLST; 1.1 percent). The screening population comprised individuals who had smoked at least 30 pack years and those who had quit in previous 15 years in NLST, and Asian men and women who had never smoked and had an additional risk factor such as family history of lung cancer in TALENT. [J Thorac Oncol 2023;doi:10.1016/j.jtho.2021.01.318; N Engl J Med 2011;365:395-409; https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening]

Shum noted that the definition of a positive screen varied among the three trials. For example, FANSS followed the Lung-RADS guidelines, which define positive screen as having ground glass opacity (GGO) of at least 30 mm. But with TALENT, a positive finding for GGO was >5 mm.

“Looking at this, it made us wonder about the number of ground glass lesions that were found in our participants. Of the 201 participants, there were 28 who had ground glass lesions. About half of them were found to have GGO of >5 mm,” including 10 with Lung-RADS 2, Shum said.

If the TALENT criteria of a positive screen with GGO >5 mm were to be applied, then lung cancer detection rate in the FANSS cohort would be brought up to 2.5–2.9 percent, she pointed out.

“This exercise is not to make any false assumptions about our findings here, but it further highlights the controversy and questions that we have about how to adequately screen a nonsmoker population. Clearly, the biology of lung cancer in smokers and nonsmokers is very different, so our management guidelines are also going to need to have some variations,” Shum said.

When developing alternative management strategies for LDCT in nonsmoking Asian women, Shum stressed that the following questions be considered: What is the interval of repeat scans that are needed? In a seemingly indolent cancer, is it considered overdiagnosis? When should we intervene on GGOs? “More biomarker testing and other technologies to help us make these decisions are needed.”

The FANSS study is ongoing and is expanding to additional sites in the US, with a target population size of 1,000 women overall. Shum shared that she and her team are collecting plasma-based cell-free DNA samples to be processed as a possible early detection tool. She also said that radiomics and AI technology will be incorporated to the CT scans to see if it helps in regard to management decisions in the population of nonsmoking Asian women.