# A Trend Analysis of Metastatic Lung Cancer Disparities in the United States in the Era of Lung Cancer Screening

## TL;DR

This study examines how lung cancer screening has affected cancer rates in the U.S., finding that some groups still face disparities.

## Contribution

The study provides new insights into how lung cancer screening has reduced metastatic lung cancer rates and narrowed disparities in certain populations.

## Key findings

- Metastatic lung cancer incidence declined more rapidly from 2014 to 2019 compared to 2004 to 2014 in both men and women.
- Disparities in metastatic lung cancer incidence narrowed from 2014 to 2019, particularly among men and women.
- Non-Hispanic American Indian/Alaskan, non-Hispanic Asian/Pacific Islander, and Hispanic patients showed no significant trend change in metastatic lung cancer incidence.

## Abstract

Background: The introduction of low-dose chest computed tomography (LDCT) screening has shown promise in improving early detection and reducing lung cancer mortality. Nonetheless, marginalized communities have displayed limited participation in lung cancer screening, potentially diminishing its advantages within these populations. We assessed the trends in metastatic lung cancer incidence and evaluated disparities by sex, race/ethnicity, and residence type in the United States.

Methods: We analyzed data from 445,715 adults aged between 55 and 80 years with metastatic lung cancer in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2019. We generated age-adjusted incidence rates (AAIR) and used Joinpoint regression models to estimate the average annual percentage change (AAPC) in incidence across different subgroups. We employed the Joinpoint test of parallelism to identify differences in metastatic lung cancer incidence by sex, race/ethnicity, and residence.

Results: The incidence of metastatic lung cancer declined more rapidly from 2014 to 2019, compared with 2004 to 2014, in men (AAPC 5.5% (2014 to 2019), 2.3% (2004-2014)) and women (1.7% (2014-2019), 0.86% (2004-2014)), with the test of parallelism indicating narrowing of disparities from 2014 to 2019. Similarly, metastatic lung cancer incidence declined more rapidly from 2014 to 2016 in metropolitan and non-metropolitan residents, with parallel trend lines. However, among racial groups, only White and Black patients had a significant reduction in metastatic lung cancer incidence from 2014 to 2019.

Conclusions: Our analysis revealed a significant decline in metastatic lung cancer incidence in most groups since 2014, coinciding with the implementation of LDCT screening. Non-Hispanic American Indian/Alaskan, non-Hispanic Asian/Pacific Islander, and Hispanic patients, however, showed no significant trend change during the study period.