Medicaid Expansion Associated with Improved Mortality in 3 Major Cancer Types

Medicaid expansion was found to be associated with improved mortality among patients with newly diagnosed breast, colorectal, and lung cancer.

Among patients with newly diagnosed breast, colorectal, and lung cancer, Medicaid expansion was found to be associated with improved mortality, according to a cross-sectional study published in JAMA Network Open.1

Moreover, this observed association appeared to be mediated by earlier stage of cancer diagnosis and did not differ by race or area-level income.

“Increased Medicaid coverage may remove barriers to accessing the healthcare system for screening and timely symptom evaluation, and that can translate into better outcomes for patients,” lead author Miranda Lam, MD, MBA, of Dana-Farber, Brigham and Women’s Hospital, and Harvard T.H. Chan School of Public Health, said in a press release.2

In order determine whether Medicaid expansion is associated with improved mortality among patients with cancer, researchers evaluated patients in the National Cancer Database with newly diagnosed breast, lung, or colorectal cancer from January 1, 2012, to December 31, 2015. The primary end point was mortality rate according to whether the patient lived in a state where Medicaid was expanded.

Overall, 523,802 patients (women, n = 385,739 [73.6%]; mean age, 54.8 years) had a new diagnosis of invasive breast (n = 273,272 [52.2%]), colorectal (n = 111,720 [21.3%]), or lung (n = 138,810 [26.5%]) cancer. Moreover, 289,330 patients (55.2%) lived in Medicaid expansion states, and 234,472 patients (44.8%) lived in nonexpansion states.

Following Medicaid expansion, mortality significantly decreased in expansion states (HR, 0.98; 95% CI, 0.97-0.99; P = .008) but not in nonexpansion states (HR, 1.01; 95% CI, 0.99-1.02; P = .43), resulting in a significant difference-in-difference (DID; HR, 1.03; 95% CI, 1.01-1.05; P = .01). This difference was shown primarily in patients with nonmetastatic cancer (stages I-III). Importantly, the investigators also observed that the decrease in mortality in Medicaid-expansion states occurred across population groups.

“We were reassured to find that patients living in areas of the lowest quartile of median household income showed a modest decrease in mortality after Medicaid expansion,” said Lam. “We also found that the mortality improvements occurred in both Black and white populations.”

After the investigators adjusted for cancer stage, the mortality improvement in expansion states from the periods before and after expansion was no longer noticeable (HR, 1.00; 95% CI, 0.98-1.02; P = .94), and neither was the difference between expansion vs nonexpansion states (DID HR, 1.00; 95% CI, 0.98-1.02; P = .84). This suggests that the decline in mortality associated with Medicaid expansion is associated of diagnosing cancer at an earlier stage.

“It is possible that increased development and use of immunotherapies has decreased mortality in most of these groups over time, especially in the metastatic setting, for which most immunotherapies are initially tested and approved,” the authors suggested. “Also, with increased focus and attention on palliative care, it is possible that patients with metastatic disease are receiving better end-of-life care in both expansion and nonexpansion states.”

The researchers noted that moving forward, longer follow-up would be helpful in understanding whether this mortality improvement continues.


1. Lam MB, Phelan J, Orav EJ, Jha AK, Keating NL. Medicaid Expansion and Mortality Among Patients With Breast, Lung, and Colorectal Cancer. JAMA Network Open. doi: 10.1001/jamanetworkopen.2020.24366

2. Medicaid expansion linked to lower mortality rates for three major types of cancer [news release]. Boston. Published November 4, 2020. Accessed November 18, 2020.