Medicaid Expansion Under the ACA Led to Earlier Cancer Diagnoses

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Finding cancer early is a key step to reducing cancer mortality, and a new study suggests that Medicaid expansion under the Affordable Care Act led to more and earlier cancer detection.

Public health insurance may increase cancer detection, which can lead to fewer deaths from cancer and better outcomes for patients, suggested new research published Thursday in the American Journal of Public Health. Researchers from Indiana University (IU) found that the Affordable Care Act (ACA) led to an increase in the number of cancer diagnoses, particularly those at the early stages, in states where Medicaid was expanded.

Researchers looked at cancer registry data from 2010 through 2014 to estimate post-ACA changes in county-level cancer diagnosis rates, both overall and by stages of cancer, in states that expanded Medicaid in 2014 versus those that did not. They collected data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program. The program, a coordinated registry of patients with cancer in the United States, covers 28% of the population and is representative of national demographics.

Of the 13 states participating in SEER, 9 expanded Medicaid by 2014; 4 did not.

Medicaid expansion led to 6.4% increase for finding cancer in the early stages (or 15.4 early-stage diagnoses per 100,000 people), from pre-ACA levels. The overall cancer diagnosis rate rose by 3.4% in Medicaid expansion states, compared with non-expansion states.

“States that participated in Medicaid expansion experienced much greater increases in cancer detection than states that did not expand,” Aparna Soni, a doctoral candidate in business economics and public policy in the IU Kelley School of Business, wrote in an e-mail to The American Journal of Managed Care®. “Our study implies that even after adjusting for county characteristics, the ACA Medicaid expansions increased overall cancer diagnosis by 3% and early-stage diagnosis by 6% in the first full year after expansion. What this means for the 18 states that have not yet adopted the Medicaid expansion is that expanding their public health insurance programs may improve cancer detection, which is associated with better patient outcomes, including reduced mortality.”


Early-stage diagnoses were considered those that were in situ, local, or regional by direct extension only. The study defined breast, cervical, prostate, lung and bronchus, and colorectal cancers as cancers amenable to early screening, and the remaining cancer sites as non-amenable.

There was no detectable impact on late-stage diagnoses.

“The fact that the increase in early-stage diagnoses was concentrated in cancers amenable to screening is consistent with the increase resulting from the expansion of health insurance and access to care,” the researchers wrote in the paper.

The news follows research announced in October by some of the same authors that patients with cancer gained insurance coverage under the ACA.

A main goal of the ACA is to significantly reduce the number of those without health insurance by providing a range of affordable coverage options through Medicaid and the health insurance marketplaces. The ACA expands Medicaid coverage for most low-income adults to 138% of the federal poverty level.

While the Trump administration has achieved a central aim of undoing the ACA by removing the financial penalty for not having individual health insurance within the tax bill sent to his office Wednesday by Congress—a move that the Congressional Budget office estimates will cause the number of people without health insurance to rise by 13 million—states could still implement a Medicaid expansion at any time.

In another interesting finding, the age of the patients studied were in their prime working years—so finding cancer earlier, rather than later, could have other economic effects.

“We did find that most of the increase in early cancer detection came from people aged 35 to 54. The fact that early cancer detection increased for this age group post-ACA is particularly meaningful because of the important social and economic roles that this population plays,” said Soni. “This is a key population for many reasons—this age group is most likely to have children below the age of 18 whom they support. They also form a large chunk of the US labor force and are often in senior positions responsible for training younger employees. Earlier cancer detection—which is associated with more successful treatment, lower probability of death, and reduced medical costs—for the 35 to 54 age group may have spillover effects that benefit the patients’ families, workplaces, and society as a whole.”

The authors wrote that reducing Medicaid funding may hurt doctors’ and patients’ ability to detect cancer, the second leading cause of death, at earlier stages.


Soni, A, Simon, K, Cawley, J, Sabik L. Effect of Medicaid expansions of 2014 on overall and early-stage cancer diagnoses [oublished online December 21, 2017]. Am J Public Health. doi: 10.2105/AJPH.2017.304166.