Incidence rates of lung cancer subtypes vary across global regions, according to study results presented at the 2023 World Conference on Lung Cancer.
The study showed that, in 2020, Eastern Europe had the highest rate of squamous cell carcinoma (SCC), Eastern Asia had the highest rate of adenocarcinoma, and Western Europe had the highest rate of small cell lung cancer (SCLC).
Researchers calculated age-standardized incidence rates (ASRs) for SCC, adenocarcinoma, and SCLC using data from the Cancer Incidence in Five Continents Project Volumes XI and the Global Cancer Observatory 2020.
There were an estimated 1,029,794 cases of adenocarcinoma, 610,051 cases of SCC, 277,510 cases of SCLC, and 289,254 cases of other histologies among lung cancer diagnoses worldwide in 2020.
The proportion of the 3 main subtypes was 46.67% for adenocarcinoma, 27.65% for SCC, and 25% for SCLC.
This is a shift from a few decades ago, when SCC was the most dominant subtype, according to study presenter Jia Wang, MD, of Peking University Cancer Hospital & Institute in Beijing, China. He speculated that the change is due to changes in cigarette composition and the emerging use of filtered cigarettes with low tar and nicotine content.
Dr Wang also showed that the most common lung cancer subtypes differed across regions. The highest ASR for adenocarcinoma was in Eastern Asia (18.66), followed by Western Europe (14.02) and North America (13.80).
For SCC, the highest ASRs were observed in Eastern Europe (12.69), Eastern Asia (8.88), and Northern Europe (8.44). The highest ASRs for SCLC were seen in Western Europe (5.62), Northern Europe (5.25), and North America (5.00).
Dr Wang said the high rate of tobacco smoking and the association between tobacco and subtypes of lung cancer were important contributors to the regional disparities.
Sex disparity was also observed across histologic subtypes. Adenocarcinoma was the most common subtype in women, and SCC was the most common subtype in men. Dr Wang said this difference might be explained by differences in risk factor exposure and lung cancer screening.
“The estimation of lung cancer incidence by histological subtype is crucial for identifying vulnerable populations, formulating appropriate intervention strategies, and monitoring the progress of prevention programs, especially for those low- and middle-income countries without a high-quality cancer registry system,” Dr Wang said.
Disclosures: No disclosures were provided.
Wang J, Wang M. The global landscape of lung squamous cell carcinoma, lung adenocarcinoma, small cell lung cancer incidence in 2020. Presented at WCLC 2023. September 9-12, 2023. Abstract OA04.06.