“Lung cancer in never-smokers is a global rising threat,” said lead researcher Pan-Chyr Yang, MD, PhD, chair professor at the National Taiwan University Hospital and academician of Academia Sinica, Taiwan.
In Taiwan, more than half of the cases of lung cancer occur in never-smokers; among female lung cancer patients, 93% are never-smokers.
The incidence of lung cancer – in particular, adenocarcinoma – is increasing in Taiwan, even though the prevalence of smoking has fallen dramatically in men in recent years and has remained low in women.
At the 2020 World Conference on Lung Cancer, which was rescheduled for January 2021, Dr. Yang presented new results that suggest “LDCT screening for never-smokers with high risk may be feasible.”
The Taiwan Lung Cancer Screening in Never-Smoker Trial (TALENT) recruited over 12,000 individuals aged 55-70 years who had never smoked or had done so more than 15 years previously and had risk factors such as a family history of the disease or passive smoke exposure, or who had regularly been exposed to frying food.
Participants underwent LDCT after chest x-ray, followed by biopsy if necessary.
These procedures detected largely invasive lung cancer in 2.6% of participants. Tumors were of stage 0-I in 95% of cases.
The lung cancer detection rate of 2.6% in TALENT in never-smokers is higher than has been found in large studies of smokers, including the 1.1% rate recorded in the NLST study and the 0.9% seen in the NELSON study.
The key factor associated with increased prevalence of lung cancer was a first-degree family history of the disease, Dr. Yang reported.
Notably, having a sister with lung cancer increased the risk for the disease by 78%. Having an affected brother doubled the risk. An increase in the number of first-degree relatives with lung cancer also significantly increased the risk.
More research needed
The TALENT study “provides new, very original evidence on lung cancer risks, and therefore lung cancer screening eligibility could be redefined in Asia, or at least in East Asia,” said the discussant for the paper, Ugo Pastorino, MD, director of thoracic surgery at IRCCS Istituto Nazionale dei Tumori Foundation, Milan.
However, he said that “more research is needed on lung cancer biology in nonsmokers.”
There is currently no follow-up or mortality data, and given the proportion of patients who underwent invasive procedures, it could be that more than 40% of those procedures were carried out in individuals with benign disease, he cautioned.
On Twitter, Stephen V. Liu, MD, director of thoracic oncology at Georgetown University, Washington, said that although family history “emerges” from the study as a potential risk factor for lung cancer, “this analysis would be much more insightful with genomic analyses of these cancers.”
Devika Das, MD, clinical assistant professor of hematology and oncology, University of Alabama at Birmingham, said that the study is “interesting,” given the rise of adenocarcinoma among never-smokers.
She agreed that further details and long-term outcomes are needed and said the key learning point was the need for a “robust” study of the biology of lung cancer in this population.
Lillian Leigh, an Australian lawyer and a lung cancer patient advocate, said the study “provides new evidence” on lung cancer risks.
“As an Asian never-smoker living with lung cancer, the TALENT trial results give me hope,” she said.
