Expansion of access to cancer care via Medicaid can help lower both incidence and mortality rates for cancer. State-run Medicaid insurance has resulted in decreased metastatic cancer incidence rates, as well as decreased overall cancer mortality rates, and averted over 1,000 deaths due to cancer per year. About 12 percent of the improvements in cancer mortality were due to decreases in metastatic diagnoses, according to new research presented at the 2022 ASCO Quality Care Symposium, based on a nationwide analysis performed to determine the degree to which expansion-associated changes in cancer mortality rates can be explained by changes in stage at diagnosis.
The researchers determined that being able to diagnose cancer at an advanced or distant stage had an important impact on cancer mortality rates, supporting the hypothesized mechanism that Medicaid expansion led to a shift towards earlier diagnoses, resulting in improved prognoses and ultimately fewer cancer deaths. Contrary to expectations at the start of the study, the researchers did not see any expansion-associated changes in localized cancer incidence rates.
"Perhaps the most surprising finding in our study was the lack of change in localized cancer incidence rates in states with Medicaid expansion, as it has been believed that the expansions might have increased access to cancer screening and enabled patients to see a physician earlier for cancer-related symptoms," noted lead author Justin Michael Barnes, MD, a resident in the Department of Radiation Oncology at the Washington University School of Medicine in St. Louis. "Some studies have shown that Medicaid expansion effects on localized cancer incidence rates dissipate over time, which is perhaps consistent with our findings looking at the entire post-expansion period from 2014 until 2019 in aggregate."
About the Study
Expansion of state-run Medicaid programs was enabled by passage of the Affordable Care Act in 2014. Earlier studies have shown that the expansion led to earlier cancer diagnoses and improved cancer survival in many states. However, it has been uncertain if the expansion-associated survival benefits were driven primarily by early detection leading to improved prognosis and/or increased access to appropriate cancer care.
In the new study (Abstract 74), the researchers obtained state-level cancer incidence and mortality data from 2001 to 2019 for people 20-64 years of age from the combined Surveillance, Epidemiology, and End Results and National Program of Cancer Registries databases (incidence) and the National Center for Health Statistics (mortality), which cover the 50 U.S. states and Washington, DC. Analyses were conducted to compare changes in localized and distant stage cancer incidence rates and cancer mortality rates from pre- and post-2014 expansion versus non-expansion states. The data consisted of 16,470 state-year observations stratified by age, sex, and race.
Key Findings
For all cancer sites combined, there was about a 3.3 percent decrease in the distant stage cancer incidence rate and about a 3.5 percent decrease in the cancer mortality rate in expansion states relative to non-expansion states. These estimates translated to 2,612 averted distant stage cancer diagnoses and 1,031 averted cancer deaths per year in the Medicaid expansion states. About 12 percent of those improvements in cancer mortality were calculated to be due to decreases in metastatic diagnoses. By cancer site, there were Medicaid expansion-associated decreases of about 3.6 percent in cancer mortality rates for breast cancer and about 6 percent for cervical cancer.
Local or distant stage incidence rates were not found to be statistically significant mediators. In conclusion, the researchers stated: "Approximately 12 percent of the improvements in cancer mortality can be attributed to decreases in metastatic diagnoses, suggesting increased rates of curative-intent treatment, amongst other factors. Remaining survival benefits may reflect access to timely, quality cancer care not captured in this analysis."
Next Steps
The researchers noted that five additional states expanded Medicaid after the end of the study period in late 2019. Assuming a relatively similar impact of expansions in these states as in the ones that were studied, they expect a larger number of averted distant stage cancer diagnoses and cancer deaths. However, they noted that future analyses incorporating data after 2019 will face the challenges of interpreting changes in the context of the COVID-19 pandemic.
In addition, the researchers hope to examine other potential mediators of Medicaid expansion-associated changes in overall survival, such as timely receipt of therapy and quality of treatment.
ASCO Chief Medical Officer and Executive Vice President Julie R. Gralow, MD, commented: "Medicaid expansion has clearly saved thousands of lives that would have been lost to cancer, as this new study shows. But insurance expansion can only move the needle so far and can't alone overcome structural barriers rooted in the social determinants of health that many patients face. Interventions that support care for marginalized populations should be considered along with Medicaid expansion efforts."
Mark L. Fuerst is a contributing writer.