Trends and Patterns of Disparities in Burden of Lung Cancer in the United States, 1974-2015

Abstract

Background: Although lung cancer incidence and mortality have been declining since the 1990s, the extent to which such progress has been made is unequal across population segments. Updated epidemiologic data on trends and patterns of disparities are lacking. Methods: Data on lung cancer cases and deaths during 1974 to 2015 were extracted from the Surveillance, Epidemiology, and End Results program. Age-standardized lung cancer incidence and mortality and their annual percent changes were calculated by histologic types, demographic variables, and tumor characteristics. Results: Lung cancer incidence decreased since 1990 (1990 to 2007: annual percent change, -0.9 [95% CI, -1.0%, -0.8%]; 2007 to 2015: -2.6 [-2.9%, -2.2%]). Among adults aged between 20 and 39 years, a higher incidence was observed among females during 1995 to 2011, after which a faster decline in female lung cancer incidence (males: -2.5% [-2.8%, -2.2%]; females: -3.1% [-4.7%, -1.5%]) resulted in a lower incidence among females. The white population had a higher incidence than the Black population for small cell carcinoma since 1987. Black females were the only group whose adenocarcinoma incidence plateaued since 2012 (-5.0% [-13.0%, 3.7%]). A higher incidence for squamous cell carcinoma was observed among Black males and females than among white males and females during 1974 to 2015. After circa 2005, octogenarians and older patients constituted the group with the highest lung cancer incidence. Incidence for localized and AJCC/TNM stage I lung cancer among octogenarians and older patients plateaued since 2009, while mortality continued to rise (localized: 1.4% [0.6%, 2.1%]; stage I: 6.7% [4.5%, 9.0%]). Conclusions: Lung cancer disparities prevail across population segments. Our findings inform effective approaches to eliminate lung cancer disparities by targeting at-risk populations.

Keywords: disparity; incidence; lung cancer; mortality; trend.

Figure 1

Trends in Annual Lung Cancer Incidence and Mortality Rates. SCC, squamous cell carcinoma. Data markers denote the observed incidence and mortality rates (cases per 100,000 person-years). The slope of the lines represents APC; vertical tics on these lines represent the joinpoints. Rates are age-adjusted to the 2,000 US standard population. (A) Overall lung cancer incidence and incidence by histologic type. (B) Overall lung cancer mortality and mortality by histologic type. (C) Overall lung cancer incidence and mortality among young adults aged 20–39 years.

Figure 2

Trends in Annual Lung Cancer Incidence Rates by Sex and Race According to Histologic Type. (A) Age-standardized incidence rate for small cell carcinoma. (B) Age-standardized incidence rate for adenocarcinoma. (C) Age-standardized incidence rate for squamous cell carcinoma.

Figure 3

Trends in Annual Lung Cancer Incidence and Mortality Rates among Elderly Aged 80 and above by SEER stage at diagnosis. (A) Incidence and mortality rates for localized SEER stage at diagnosis. (B) Incidence and mortality rates for regional SEER stage at diagnosis. (C) Incidence and mortality rates for distant SEER stage at diagnosis.

Figure 4

Trends in Annual Lung Cancer Incidence and Mortality Rates among Elderly Aged 80 and above by TNM stage at diagnosis. (A) Incidence and mortality rates for TNM stage I at diagnosis. (B) Incidence and mortality rates for TNM stage II at diagnosis. (C) Incidence and mortality rates for TNM stage III at diagnosis. (D) Incidence and mortality rates for TNM stage IV at diagnosis.