Temporal trends in pregnancy-associated cancer mortality in the United States: A national analysis 2018-2023.

11029 Background: Cancer during pregnancy is rare but increasing due to rising rates of early-onset cancers and more parents delaying childbearing to older ages. Cancer treatment during pregnancy is complex, as capacity to deliver timely, multimodality anti-cancer treatment may be limited by risk of fetal compromise. As pregnancy-associated cancer is an increasingly recognized contributor to maternal mortality, this study sought to evaluate national temporal trends. Methods: Using CDC WONDER Multiple Cause of Death files (2018–2023), pregnancy-associated deaths involving malignant neoplasms (ICD-10 C00–C97) were identified. Age-adjusted mortality rates (AAMR) per 100,000 live births and annual percent changes (APCs) were calculated, excluding unknown race, ethnicity, or age. AAMR was evaluated by state, including comparison of 1) states with trigger laws banning abortion in 2022 vs states that did not have such laws and 2) states that expanded Medicaid by 2018 vs states that did not. Mortality data for locations with <10 deaths is censored. Results: From 2018–2023, there were 723 pregnancy-associated deaths in people with cancer. Most (72%) were in White patients and occurred in the late postpartum period (59%) (42-365 days after birth). Only 19% of patients had documented metastatic cancer. Overall AAMR was 3.40 (95%CI 3.16–3.65); it was highest among Black patients (4.54), exceeding White (3.24), Hispanic (3.08), and AIAN/AAPI (2.64) mortality. Breast (n=162, AAMR 0.76 95%CI 0.65-0.88) had the greatest cancer-specific mortality burden, followed by hematological malignancies (n=101, AAMR 0.48, 95% CI 0.38-0.57) and colorectal cancer (n=71, AAMR 0.12, 95%CI 0.088-0.15). AAMR for those with metastatic disease was 0.64 and increased over time (APC +7.54%; 95%CI 1.52–14.55; p=0.009). Late maternal deaths also rose (APC +4.75%; 95%CI 0.99–8.87; p=0.006). Otherwise, overall (APC −0.37%, 95%CI -0.37-4.30, p=0.83) and race/ethnicity specific pregnancy-associated cancer mortality have not significantly changed over time. Among 25 states with ≥10 deaths, state-level mortality ranged from 1.37 in California to 6.95 in Virginia. Limited state comparative analysis found that AAMR for pregnancy-associated cancer was higher in states with trigger laws (4.43) compared to non-trigger states (3.22); it was also higher in non-Expansion states (4.00) compared to states that expanded Medicaid (3.31). Conclusions: Despite known improvements in cancer mortality, pregnancy-associated cancer mortality remains stagnant, with notable mortality rises in pregnant patients with metastatic disease and late postpartum deaths. The large variability in state-level mortality may reflect state policies that affect access to prenatal or oncological care. More research and advocacy work to optimize care for pregnancy patients with cancer is essential to improve outcomes for this vulnerable population.