Advances in New Therapies Leading to Reduction in Lung Cancer Mortality

October 2020, Vol 11, No 5

The overall mortality for lung cancer has declined in the United States, but little is known about the mortality trends by lung cancer subtype, because death certificates do not record this information. To address this limitation in the data collection, the Surveillance, Epidemiology, and End Results (SEER) program has linked mortality records to incident cancer cases in all cancer types. Using SEER data, researchers from the National Cancer Institute assessed lung cancer mortality and linked deaths from lung cancer to incident cases in SEER cancer registries (Howlader N, et al. N Engl J Med. 2020;383:640-649). The analysis included SEER data from 2001 through 2016.

For this study, the researchers looked at data for 2 major histologic subtypes of lung cancer—non–small-cell lung cancer (NSCLC), which accounts for 76% of lung cancer in the United States, and small-cell lung cancer (SCLC), which accounts for 13%.

The results showed that in recent years, deaths from NSCLC decreased faster than the increase in incidence of NSCLC, and the decreases in death were associated with significant improvement in survival over a period of time that matched the approval of new targeted therapies for lung cancer.

Among men, deaths from NSCLC decreased by 3.2% annually between 2006 and 2013 and 6.3% annually between 2013 and 2016; by contrast, the incidence of NSCLC decreased gradually, by 1.9% annually, between 2001 and 2008, and by 3.1% annually between 2008 and 2016.

For women, incidence-based mortality decreased slowly, by 2.3% annually, between 2006 and 2014, and then at a faster rate of 5.9% annually between 2014 and 2016. In contrast, the incidence of NSCLC in women was flat between 2001 and 2006, before declining by 1.5% annually between 2006 and 2016.

The 2-year survival for men with NSCLC improved significantly over time, from 26% for patients diagnosed in 2001 to 35% for those diagnosed in 2014. By contrast, the 2-year survival for women diagnosed with NSCLC was higher for the same period, 35% and 44%, respectively.

“The faster decreases in lung-cancer incidence among men than among women can be attributed to the relative differences in smoking prevalence according to sex,” explained the researchers.

However, the analyses for SCLC showed that the decline seen in mortality resulted almost entirely from the decline in the incidence rate of SCLC, according to the researchers, which corresponds to the lack of new therapies for this patient population, as can be seen by the very limited treatment advances for SCLC over the same period. For example, among men with SCLC, the 2-year survival did not change over the study period from 2001 to 2016 (12% and 11%, respectively).

“We anticipate that incidence-based mortality methods will be valuable for evaluating trends in subtype-specific mortality in the future, as additional new lung-cancer treatments, as well as screening, are disseminated in the population,” concluded the researchers.

Related Articles