Background: Thymic epithelial tumors (TETs), including thymoma and thymic carcinoma, are rare in young patients, with limited data on clinical characteristics and outcomes. We aimed to evaluate demographics, treatment strategies, and outcomes in pediatric/adolescent, and young adult (YA) patients with TETs.
Methods: The National Cancer Database was queried for patients aged 0-39 years with thymoma or thymic carcinoma from 2004-2019. Descriptive statistics were performed, and overall survival was analyzed using Cox regressions. Kaplan-Meier analysis was stratified by age (pediatric/adolescent: 0-21 years; YA: 22-39 years) and tumor type.
Results: 1,069 patients were identified, of which 193 (18%) had thymic carcinoma and 876 (82%) had thymoma. Pediatric/adolescent patients accounted for 98 cases (9%). Most patients underwent surgical resection (77%), primarily via open approach (72%); fewer received radiation (43%) or chemotherapy (45%). Five-year survival was 36% for thymic carcinoma and 87% for thymoma. On multivariable analysis, thymic carcinoma (HR 2.9, p<0.001), advanced Masaoka stage (III: HR 2.0, p=0.001; IV: HR 3.0, p<0.001), positive margins (HR 1.6, p=0.015), and chemotherapy (HR 1.5, p=0.020) were associated with worse survival, while surgery (HR 0.2, p<0.001) and older age (HR 0.97, p=0.002) were associated with improved survival. Thymic carcinoma outcomes were significantly worse for pediatric/adolescent patients compared to YAs (p=0.03) - a difference not observed in thymoma (p=0.17).
Conclusion: Thymic carcinoma and advanced disease predict poor survival, while complete resection is associated with improved outcomes. Notably, younger patients with thymic carcinoma have significantly worse survival, highlighting the need for age- and histology-specific treatment strategies.
Purpose: We investigated whether transamniotic fetal mRNA vaccination could be a viable strategy for perinatal immunization against Zika virus (ZIKV) infection in a rodent model.
Methods: Twenty pregnant Sprague Dawley dams underwent volume-matched intra-amniotic injections in all their fetuses (n = 280) of either a suspension of a custom-made mRNA encoding for the ZIKV pre-membrane (ZIVK-prM) and envelope (ZIKV-E) structural proteins encapsulated in a semi-synthetic composite lipopolyplex (vaccinated, n = 153), or of the same lipopolyplex without mRNA (control, n = 127) on gestational day 17-18 (E17-18; term = E21-22). Pup serum levels of ZIKV-E antigen-specific IgG antibodies were measured by ELISA at term up to 3 months of age. Splenocyte and lymph node cell suspensions were incubated either with or without ZIKVE challenge, followed by flow cytometry to assess T-cell response.
Results: When controlled by mRNA-free injections, ZIKV-E-specific IgG was not detected in the serum of term fetuses; however, levels were significantly elevated in vaccinated pups from postnatal day 5-16 (p = 0.005-0.002). Splenocytes from vaccinated pups showed significant increases in IL-6 and IFN- γ productions after the antigen-specific challenge at 2 and 3 months (p = 0.049 to 0.003 vs. nonchallenged cells), along with a significant decrease in IL-13 production at 3 months (p = 0.006). Lymph node cells also demonstrated increased production of IFN-γ (p < 0.001 vs. non-challenged cells), along with a significant decrease in IL-13 production, both at 3 months (p = 0.014).
Conclusions: Transamniotic fetal mRNA vaccination with a Zika virus antigen can induce adaptive humoral and cellular immune responses extending into the neonatal period in a healthy rat model.
Level of evidence: N/A (animal and laboratory study).
Type of study: Animal and laboratory study.

