Decline in SCLC Incidence Expected to Accelerate Through 2050

Small cell lung cancer (SCLC) incidence is projected to continue rapidly declining in the coming years as fewer and fewer Americans smoke tobacco products, according to a new analysis.¹

The forecasted drop in cases through the year 2050 would accelerate a trend that was observed between 2000 and 2021. The findings were presented at the American Society of Clinical Oncology 2025 annual meeting.

First author Mariah Malak Bilalaga, MD, of MedStar Health, and colleagues explained that only a limited number of studies have analyzed the population-level incidence of SCLC in the US.

Analyzed by birth cohort, the authors found each successive birth cohort had a 7.7% decline in SCLC rates. | Image credit: shidlovski

“Given recent demographic changes, including an aging population and increased racial diversity, updated estimates are warranted,” Bilalaga and colleagues wrote. A better understanding of trends in SCLC incidence could help policymakers better plan for future health care needs.

The investigators used the Surveillance, Epidemiology, and End Results (SEER 17) database to identify adults who were diagnosed with SCLC between 2000 and 2021. They found a total of 120,128 cases. The mean patient age was 67 years, and they were evenly split between males and females. Most of the patients who were diagnosed with SCLC were non-Hispanic White (82.9%), followed by non-Hispanic Black (8.1%).

Bilalaga and colleagues found a significant, steady decline in cases over the 2-decade period. Adjusted for age, Bilalaga and colleagues found the incidence of SCLC per 100,000 fell from 11.9 (95% CI, 11.6-12.2) in 2000 to 6.0 (95% CI, 5.8-6.2) in 2021. That translates to an annual percent change of –4.3% (95% CI, –4.9 to –3.7). The declines were similar among males and females and among non-Hispanic White patients and non-Hispanic Black patients.

Analyzed by birth cohort, the authors found each successive birth cohort had a 7.7% decline in SCLC rates (95% CI, –12.2 to –3.0).

Using those historic data, the authors then forecasted how rates of SCLC might change in the future. Their analysis suggests that between 2022 and 2050, the incidence of SCLC will likely decrease at an even faster rate, with a projected annual percentage change of –5.5% (95% CI, –8.0 to –3.0) for males, a 6.2% annual decrease for females (95% CI, –8.8 to –3.7), a 6.1% annual decline for non-Hispanic Whites (95% CI, –9.1 to –3.3), and an annual change of –5.7% for non-Hispanic Blacks (95% CI, –14.6 to –2.3). Overall, that translates to an annual decrease of 5.9% (95% CI, –8.5 to –3.5).

The investigators said more research will be needed to explain exactly why the decreases are happening, but they suggested it has to do with changing patterns of tobacco use.

“This reduction could be due to a substantial shift in smoking habits, highlighting the importance of tobacco control efforts,” they wrote.

A 2023 study found that between 2011 and 2022, the percentage of young adults (ages 18-24) who smoked dropped from nearly 1 in 5 to just 4.9%, while remaining nearly constant for adults ages 65 and older.²

According to the American Cancer Society, approximately 80% of lung cancer deaths are believed to be related to smoking, though they said the actual number may even be higher given the rarity of SCLC in patients who have never smoked.³ 

References

1. Bilalaga MM, Gaddipati GN, Vasireddy R, et al. Trends in small cell lung cancer incidence and projections of future burden through 2050. J Clin Oncol. 2025;43(suppl 16):Abstract e20119. doi:10.1200/JCO.2025.43.16_suppl.e20119

2. Meza R, Cao P, Jeon J, Warner KE, Levy DT. Trends in US adult smoking prevalence, 2011 to 2022. JAMA Health Forum. 2023;4(12):e234213. doi:10.1001/jamahealthforum.2023.4213

3. Lung cancer risk factors. American Cancer Society. Accessed June 16, 2025. https://www.cancer.org/cancer/types/lung-cancer/causes-risks-prevention/risk-factors.html