Study adds evidence linking Medicaid expansion to earlier lung cancer diagnosis and improved survival

For people diagnosed with lung cancer, timing can make the difference between treatable disease and a life-threatening prognosis. New findings add further support that expanding access to health insurance may play a critical role in improving outcomes.

Medicaid expansion under the Affordable Care Act was associated with earlier diagnosis, more timely treatment and improved survival for people with non-small cell lung cancer (NSCLC), according to new research led by Jingxuan Zhao, Ph.D., M.P.H., a senior scientist at the American Cancer Society.

The nationwide study, published in February 2026 in the Journal of Clinical Oncology, found that broader insurance coverage corresponded with measurable improvements across several stages of lung cancer care, including stage at diagnosis, treatment timing and five-year survival.

Lung cancer remains the leading cause of cancer-related death in the United States, accounting for more deaths each year than breast, colorectal and prostate cancers combined. Non-small cell lung cancer (NSCLC) is the most common form of the disease, and many people are diagnosed after the cancer has already spread. Early detection and prompt treatment are key factors that can significantly improve survival.

In their analysis, Zhao and colleagues assessed whether Medicaid expansion under the Affordable Care Act was associated with differences in cancer diagnosis, treatment and survival among people with NSCLC. The investigators analyzed nationwide data from the National Cancer Database, including adults ages 18 to 64 who were diagnosed with stage 1 through 4 NSCLC between January 2004 and December 2023.

The study compared outcomes between people living in states that expanded Medicaid eligibility and those living in states that did not. Medicaid expansion, first implemented in 2014, allowed adults younger than age 65 with household incomes up to 138% of the federal poverty level to qualify for coverage. To evaluate the policy’s impact, the researchers examined several measures across the cancer care continuum, including stage at diagnosis, how quickly people began treatment, whether they received guideline-concordant care and five-year overall survival.

The analysis included more than 514,000 people with NSCLC. Of these, about 350,000 lived in Medicaid expansion states and approximately 164,000 lived in states that did not expand the program.

Overall, the study found that Medicaid expansion was associated with improvements in earlier diagnosis, faster treatment initiation and improved survival, with particularly strong benefits for individuals living in lower socioeconomic areas.

People living in expansion states were more likely to be diagnosed at an earlier stage of disease. The researchers observed a 1.02 percentage point increase in early-stage diagnoses, defined as stage 1 or 2 NSCLC, compared with people in non-expansion states.

The study found differences in how quickly people began treatment. Although timely treatment initiation declined nationally over time, Medicaid expansion was associated with a smaller decrease in the likelihood that people started guideline-concordant treatment within 30 days of diagnosis. Compared with non-expansion states, expansion states saw a 2.10 percentage point relative increase in timely treatment initiation.

The analysis also linked Medicaid expansion to better long-term survival. People living in expansion states experienced a 1.79 percentage point increase in five-year overall survival compared with those in states that did not expand Medicaid.

Additional analyses suggested that the benefits of expansion were not evenly distributed across populations. People living in lower-income areas appeared more likely to benefit from Medicaid expansion than those in higher-income communities, highlighting the potential role of expanded insurance coverage in reducing socioeconomic disparities in cancer care.

The survival improvements were largely attributable to increases in early-stage diagnosis in expansion states, according to the study authors. Expanded insurance coverage may make it easier for people to access preventive services, lung cancer screening and early evaluation of symptoms, which can lead to earlier detection.

Overall, the findings suggest that expanding access to health insurance may improve outcomes across multiple stages of lung cancer care.

The results also highlight the broader implications of health policy decisions on cancer outcomes. The authors estimated that nearly 5,500 people newly diagnosed with NSCLC each year could be adversely affected if Medicaid expansion were reversed.

“Federal cuts to Medicaid could undermine these gains, threatening progress in access and survival for vulnerable populations,” the authors concluded.