In 2021, cancer-related death in the United States is projected to continue to decrease, a clinical reality largely driven by declining non-small cell lung cancer (NSCLC) mortality, according to the results of a study published in CA Cancer Journal for Clinicians.1
The American Cancer Society publishes estimated projections of cancer incidence and mortality each year and associated temporal trends. These data can help identify areas where diagnosis and treatment have improved, and those in which further innovation is needed.
The population-based study evaluated cancer incidence data from the Surveillance, Epidemiology, and End Results (SEER) program registry and the North American Association of Central Cancer Registries (NAACCR). The investigators used data from the National Center for Health Statistics (NCHS) to estimate mortality and adjusted rates for delays in reporting when possible. The aim of the effort was to project cancer incidence and mortality for 2021, given that there is a 2- to 4-year lag in population-based data.
In 2021, it is estimated that a total of 927,910 women and 970,250 men will be newly diagnosed with cancer, and 289,150 women and 319,420 will die from their disease.
Lung cancer is expected to be the second leading cancer diagnosis, contributing to 13% and 12% of cancer cases among women and men in 2021, respectively. A total of 116,660 women and 119,100 men are projected to receive new lung cancer diagnoses in 2021.
The overall lung cancer incidence is decreasing by approximately 2.2% to 2.3% per year, but the rate of decline is 2-times faster in men as it is in women. This is likely due in part to “historical differences in tobacco uptake and cessation as well as upturns in female smoking prevalence in some birth cohorts,” the study authors wrote.
The recent decline in lung cancer incidence has led to a decrease in overall cancer incidence and a narrowing of the disparity of cancer incidence by sex. Notably, cancer incidence rates have decreased by 2% among women compared with 20% among men.
In both women and men, the primary cause of cancer-related death is lung cancer, which accounts for 22% of all cancer deaths. Yet, lung cancer mortality has declined, with the death rate 30% and 54% lower in 2018 than it was at its peak in women in 2002 and men in 1990, respectively.
There was a large increase in the 2-year relative survival (30%) rate for lung cancer from 2009 to 2010 and from 2015 and 2016 (36%), which was primarily due to improvements in NSCLC treatment. The relative survival for small cell lung cancer, by contrast, has remained steady.
The improvements in NSCLC survival were attributed to advances in the treatment of metastatic disease and improvements in diagnostic and surgical procedures for earlier-stage disease. Another contributor was improved access to care as a result of the 2014 Patient Protection and Affordable Care Act and Medicaid expansion.
The study authors concluded that the decrease in cancer mortality rates since 1991 was “largely due to reductions in smoking and subsequent declines in lung cancer mortality, which have accelerated in recent years because of improvement management of NSCLC.”
They added that although the coronavirus disease 2019 (COVID-19) pandemic dramatically affected the management of cancer during 2020, which is likely to continue through 2021, these effects were not reflected in these data. “This secondary consequence of the pandemic will take several years to quantify because of the lag in dissemination of population-based surveillance data,” the study authors concluded.
Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2021. CA Cancer J Clin. 2021;71(1):7-33. doi:10.3322/caac.21654