Lung cancer risk is 10-fold higher in smokers who are not recommended for annual screening

A new study by Faselis et al. (2022), has highlighted the unmet need in lung cancer screening, as their research has shown that a 10-fold high lung cancer risk has been found among light and former heavy smokers for whom computer tomography (CT) scan screening is not recommended.[i]

Cigarette smoking causes about 30% of all cancer mortality in more developed countries. It has been well established that cigarette smoke contains over 60 carcinogens, that cause cancer through various mechanisms.[ii]

In 2020, lung cancer was the leading cause of cancer death worldwide.[iii] With an estimated 3,200 deaths every year, lung cancer is also the leading cause of cancer death in Switzerland. When identified early, cancer is more likely to respond to treatment and can result in a greater probability of survival.[iv] Thus, significant improvements can be made by detecting cancer early and avoiding delays in care. The results of the US National Lung Screening Trial (NLST) showed that lung cancer screening significantly reduced lung cancer mortality by 20%. The results of another landmark study, the Dutch-Belgian Lung Cancer Screening Trial NELSON, demonstrated a 26% reduction in lung cancer deaths.[v]

Switzerland is amongst many European countries that lacks a lung cancer screening programme. To date, the USA, UK and Poland are the only countries with lung cancer screening being implemented following recommendations of various international associations.[vi] In the US, the Preventive Services Task Force (USPSTF) recommends annual screening for lung cancer with low-dose computed tomography (LDCT) in adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years.[vii]

Study Methodology:

The researchers used patient data from the Cardiovascular Health Study which enrolled nearly 6,000 community-dwelling older adults (65 years and older). Participants with incomplete smoking history, and heavy smokers, for whom lung cancer screening is recommended were excluded. Thus, a total of 4279 participants, with a mean age of 72.8 years (57.3% female) were finally included and followed for a median of 13.3 years. There were 861 current light smokers, and 615 former heavy smokers, for whom no screening is recommended and 1,973 never smokers who were used as the reference point.

Faselis et al. (2022) concluded that there appears to be a very high lung cancer risk among those who are excluded from the recommendations for CT screening and called for future studies to examine whether annual screening could reduce lung cancer mortality in these populations. Moreover, they highlight the importance of abstinence and early cessation.

In Switzerland, a national lung cancer screening programme is needed to ensure early detection and subsequent treatment.

[i] Faselis, C., Nations, J. A., Morgan, C. J., Antevil, J., Roseman, J. M., Zhang, S., Fonarow, G. C., Sheriff, H. M., Trachiotis, G. D., Allman, R. M., Deedwania, P., Zeng-Trietler, Q., Taub, D. D., Ahmed, A. A., Howard, G., & Ahmed, A. (2022). Assessment of Lung Cancer Risk Among Smokers for Whom Annual Screening Is Not Recommended. JAMA oncology, 10.1001/jamaoncol.2022.2952. Advance online publication. https://doi.org/10.1001/jamaoncol.2022.2952

[ii] Hecht, S.S. Cigarette smoking: cancer risks, carcinogens, and mechanisms. Langenbecks Arch Surg 391, 603–613 (2006). https://doi.org/10.1007/s00423-006-0111-z

[iii] Ferlay J, Ervik M, Lam F, Colombet M, Mery L, Piñeros M, et al. Global Cancer Observatory: Cancer Today. Lyon: International Agency for Research on Cancer; 2020 (https://gco.iarc.fr/today, accessed February 2021).

[iv] de Martel C, Georges D, Bray F, Ferlay J, Clifford GM. Global burden of cancer attributable to infections in 2018: a worldwide incidence analysis. Lancet Glob Health. 2020;8(2):e180-e190.

[v] Frauenfelder, T., Puhan, M., & von Garnier, C. (2020, October 8). Establishing a swiss national lung cancer screening program. UZH. Retrieved August 10, 2022, from https://www.ebpi.uzh.ch/en/translational_research/community_and_health/establishing_swiss_national_lung_cancer_screening.html

[vi] Frauenfelder, T., Puhan, M., & von Garnier, C. (2020, October 8). Establishing a swiss national lung cancer screening program. UZH. Retrieved August 10, 2022, from https://www.ebpi.uzh.ch/en/translational_research/community_and_health/establishing_swiss_national_lung_cancer_screening.html

[vii] USPST. (2021, March 9). Lung cancer: Screening. Recommendation: Lung Cancer: Screening | United States Preventive Services Taskforce. Retrieved August 10, 2022, from https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening#:~:text=Recommendation%20Summary&text=The%20USPSTF%20recommends%20annual%20screening,within%20the%20past%2015%20years.