A new study led by researchers at the American Cancer Society (ACS) shows continued cancer underdiagnosis and declines in proportion of early-stage diagnoses nationwide in 2021, the second year of the COVID-19 pandemic. However, the pattern was worse in non-expansion states, suggesting a protective effect of Medicaid expansion on cancer early diagnosis during the public health emergency.

The findings [were] presented at this year’s annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, May 31-June 4, 2024. Researchers were led by Dr. Xuesong Han, scientific director, health services research at the American Cancer Society.

They analyzed data of adults, 18-64 years old, newly diagnosed with cancer in 2019 and 2021, identified from the National Cancer Database. (Year 2020 was excluded to avoid confounding from distinct geographic patterns of COVID-19 infections.) A difference-in-differences (DD) approach was used to compare the changes in proportions of patients diagnosed at stage I/II in 2021 versus 2019 between Medicaid expansion states and non-expansion states. Adjusted DD estimates were calculated with linear probability models and stratified by key sociodemographic factors and cancer type.  

The study identified a total of 427,368 adults newly diagnosed with cancer in 2019 and 393,961 in 2021. Patients diagnosed with stage I/II decreased nationwide. Decreases were larger in non-expansion states (from 58.5% in 2019 to 57.2% in 2021) compared to expansion states (61.4% in 2019 to 60.7% in 2021), leading to a DD of 0.76 percentage points in early-stage cancer diagnosis associated with Medicaid expansion (95% CI =0.32, 1.20).

The association was strongest among individuals aged 18-44 years (DD=1.35, 95% CI=0.36, 2.34), men (DD=1.27, 95% CI=0.57, 1.97), those living in most socioeconomically deprived areas (DD=1.21, 95% CI=0.25, 2.17) and nonmetropolitan areas (DD=1.44, 95% CI=0.25, 2.63). When stratified by cancer type, the largest associations were seen for esophageal cancer (DD=2.91, 95% CI=-0.52, 6.34) and prostate cancer (DD=2.61, 95% CI=1.30, 3.92).

Researchers hope the findings may help inform policy makers and the public in the 10 states that have yet to expand Medicaid eligibility.

This news release was published by the American Cancer Society on May 28, 2024.

Click here to read the study abstract.
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