ASCO Annual Meeting

ASCO Annual Meeting

Perspective from Afsaneh Barzi , MD
June 04, 2019
3 min read

Medicaid expansion reduces racial disparities in access to timely cancer care

Perspective from Afsaneh Barzi , MD
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

CHICAGO — States that expanded Medicaid under the Affordable Care Act appeared to eliminate disparities in timely treatment for black patients with cancer compared with white patients, according to results of a retrospective observational study presented during the plenary session at ASCO Annual Meeting.

“Racial disparities in cancer-related care, access and outcomes exist across the trajectory of cancer care, from prevention to survival and other outcomes,” Amy J. Davidoff, PhD, MS, senior research scientist in public health at Yale University, said during the presentation. “While disparities have been well-documented, finding mechanisms to reduce them is more challenging. An important aspect of care is timely initiation of treatment after diagnosis. This is patient-centered and could improve outcomes in some cases.”

The ACA, passed in 2010, sought to improve equity in health care by allowing states to expand Medicaid and provide subsidies for the purchase of private insurance plans. As of 2019, 33 states and Washington, D.C., had expanded Medicaid under the ACA.

Davidoff and colleagues used the nationwide Flatiron Health electronic health record-derived database to identify 30,386 patients (median age, 57 years; 12% black) aged 18 to 64 years with advanced or metastatic cancer diagnosed between 2011 and 2018. Cancers represented in the population included non-small cell lung, breast, urothelial, gastric/esophageal, colorectal, renal cell, prostate and melanoma.

Researchers assigned each patient an expansion status based on whether their state of residence had expanded Medicaid under the ACA at the time of their diagnosis.

The primary study outcome was timely treatment, defined as treatment within 30 days of advanced or metastatic diagnosis. Researchers conducted a difference-in-differences analysis for patients with expanded vs. nonexpanded states of residence to analyze the adjusted rate of timely treatment, with regression model covariates of race, age, sex, practice type, cancer type, stage, and unemployment rate using time and state fixed-effects.

In total, 18,678 patients lived in nonexpanded states and 11,708 lived in expanded states.

Results showed that, before Medicaid expansion, adjusted rate of timely treatment was 48.3% among white patients and 43.5% among black patients. These data indicated black patients were 4.8 percentage points less likely to receive timely treatment compared with white patients (P < .001).

Regardless of race, Medicaid expansion increased the rate of timely treatment in all patients (P = .05).

Expansion led to an overall differential benefit of 6.9% for black patients and 1.8% for white patients. The adjusted rate of timely treatment was 50.3% for white patients and 49.6% for black patients, for a –0.8 percentage-point difference. Racial disparities observed prior to Medicaid expansion were not seen after the program was expanded, according to the researchers.


The difference-in-differences analysis showed a 4-percentage point reduction in disparity after Medicaid expansion (P = .042).

“Black patients benefited much more than white patients by the expansion, to the tune of a 4% reduction in disparity,” Davidoff said. “This extends prior evidence regarding the effects of the Affordable Care Act’s expansion on insurance coverage and general access for [patients with] cancer. It also tells us that national health care coverage policy may reduce disparities in cancer care.”

Limitations of the analysis include a potential misclassification of the timely treatment endpoint, that the mechanism for increasing timely treatment is uncertain, that timely treatment as an outcome cannot be linked to outcomes, and that this was an observational study that does not prove causality.

Yousuf Zafar, MD, MHS, FASCO
Yousuf Zafar

Despite the implications of these findings, cancer care injustice is not a science problem, a technology problem or a genetics problem, Yousuf Zafar, MD, MHS, FASCO, associate professor of medicine, public policy and population science at Duke Cancer Institute, who served as the plenary discussant for this study, said during the session.

Instead, he stressed the problem is with public policy and data gathering.

“Proof-of-concept that improved access to cancer care is associated with timeliness and reduced disparities,” Zafar said. “Even with improved access, quality of cancer care has room for improvement.”– by John DeRosier


Adamson BJS, et al. Abstract LBA1. Presented at: ASCO Annual Meeting; May 31-June 4, 2019; Chicago.

Disclosures: Davidoff reports a consultant/advisory role with Amgen and research funding from Boehringer Ingelheim and Celgene. Please see the study for all other authors’ relevant financial disclosures. Zafar reports consultant/advisory roles with AIM Specialty Health, Copernicus WCG, Discern Health, Family Research Foundation, McKesson, RTI Health Solutions and Vivor and research funding from AstraZeneca.