A study conducted by researchers at the 2023 ASCO Annual Meeting found significant correlations between Medicaid expansion and treatment receipt, reduced delays in treatment initiation, and overall survival among young adult women with breast cancer.

While Medicaid expansion under the Affordable Care Act has been correlated with increased insurance coverage and cancer diagnoses at an early stage for young adults, the researchers identified a need to examine if Medicaid expansion affected the treatment and survival of young adult women newly diagnosed with breast cancer. According to the researchers, young adult patients are the most common group to be uninsured, and breast cancer is their most common cancer diagnosis.

Using the National Cancer Database, the researchers examined 51,675 women aged 18 to 39 years who were diagnosed with breast cancer between 2011 and 2018. The difference-in-differences (DD) method was used to estimate outcome changes before and after Medicaid expansion, in states that did and did not take part in the expansion. 
Guideline-concordant treatment included endocrine therapy for participants with estrogen receptor (ER)-positive and progesterone (PR)-positive cancer, and chemotherapy or targeted therapy for patients with ER-negative and PR-negative cancer. Within 60 days of diagnosis, surgery, chemotherapy, and targeted therapy were initiated for stages I through III cancer, and systemic therapy was initiated for stage IV diagnoses.

To estimate 2-year overall survival, flexible parametric survival models were applied which adjusted for factors such as age, race/ethnicity, rurality, zip code-level income, comorbidity, and diagnosis year. Standard errors were clustered at the state level, and the analyses were stratified by stage at diagnosis (stages I to III vs IV).

Among women with ER-positive or PR-positive breast cancer in stages I through III, the percentage receiving endocrine therapy increased in expansion states (from 85.20% pre-expansion to 86.46% post-expansion). However, there was a decrease in non-expansion states (from 84.32% to 82.79%). Medicaid expansion was thus associated with a net 2.42 percentage point increase (95% CI = .56 to 4.28) in endocrine therapy. Furthermore, the percentage of patients who initiated treatment within 60 days of diagnosis decreased less in expansion states (from 84.10% to 82.36%) than in non-expansion states (from 86.95% to 83.98%). Treatment delays declined by 1.61 percentage points (95% CI = .05 to 3.18) in states with Medicaid expansion. 

Overall 2-year survival was also found to increase in expansion states (from 96.84% to 96.99%), but decreased in non-expansion states (from 97.24% to 96.30%), or a 1.00 percentage point increase (95% CI = .21 to 1.79) in survival associated with Medicaid expansion.

“Among [young adult] women with stage I-III breast cancer, Medicaid expansion was associated with increased receipt of guideline-concordant treatment, reduced delays in treatment initiation, and improved 2-year survival,” said researchers. 

Reference: 
Han X, Shi KS, Ruddy KJ, et all. Association of Medicaid expansion with treatment receipt, delays in treatment initiation, and survival among young adult women with breast cancer. J Clin Oncol. 2023;41(suppl 16; abstr 1509). doi:10.1200/JCO.2023.41.16_suppl.1509