A new study by researchers at ACS shows Medicaid expansion was associated with an increase in Medicaid coverage, early-stage cancer diagnoses, and improved two-year survival among patients diagnosed with cancer aged 65 years and older. The findings were presented at this year’s American Society of Clinical Oncology (ASCO) annual meeting in Chicago.

In the report, led by Kewei Sylvia Shi, MPH, associate scientist, health services research at ACS, researchers identified patients 65 years or older using the National Cancer Database. They analyzed data of newly diagnosed patients with cancer between 2010 and 2022 residing in areas with a median household income below 200% of the federal poverty level. Researchers applied a quasi-experimental difference-in-differences design, with multivariable linear probability models, to compare the changes in the percentage of dual-eligible or Medicaid-only coverage, early stage at diagnosis, and two-year survival post (vs. pre) Medicaid expansion in expansion states compared with non-expansion states.

Study results included a total of 1,461,540 patients with cancer, with 881,692 patients from expansion states and 579,848 patients from non-expansion states. After adjusting for sociodemographic characteristics, the percentage of patients with dual or Medicaid-only coverage increased from 10.3% to 11.3% in expansion states and decreased from 9.4% to 8.1% in non-expansion states, resulting in a net increase of 1.25 percentage points associated with Medicaid expansion. Differences were more pronounced among patients over 85 years, females, non-Hispanic Black, metropolitan residents, and those with comorbidities.

Early-stage (0,I,II) cancer diagnoses decreased more in non-expansion states (55.6% to 53.1%) than in expansion states (53.5% to 51.9%), resulting in a net 1.00 percentage points increase. The protective effects of Medicaid expansion were stronger for lung and bronchus and oral cavity and pharynx cancers.

Two-year overall survival rates increased from 58.8% to 62.4% in expansion states and from 59.2% to 62.5% in non-expansion states, leading to a net benefit of 0.77 percentage points. Improvements were most notable for stage IV, lung and bronchus, kidney, and bladder cancers.

Researchers stress these findings underscore the spillover benefits of Medicaid expansion in supporting low-income elderly populations and the importance of indirect benefits when evaluating Medicaid expansion’s broader impact.