The Prevalence and Significance of Established Cancer Stem Cell Biomarkers in Follicular Lymphoma Patients 2260603

Abstract Introduction Follicular lymphoma (FL), the most common form of non-Hodgkin’s lymphoma, is frequently indolent but has a high risk for multiple relapses. Despite therapeutic advances, 45% of relapsed patients have a reported median survival of 1-2 years and account for up to one third of lymphoma-related deaths. Cancer stem cells (CSCs) with self-renewal ability are thought to be responsible for tumor progression and chemo resistance. Here we investigated the prevalence and significance of CSCs biomarkers in FL patients (pts). Methods AI software Deep6 and Slicer Dicer were used for query building in EPIC (ICD-10 code: C82.9), resulting in 105 FL pts with available lymph node biopsy blocks. Demographic and clinicopathological characteristics of these FL pts were collected. FFPE blocks from 59 FL pts were collected and used to create tissue microarray slides (TMA). H&E staining and IHC staining of FL cells (CD20) and CSCs (ABCG2, Ki67, and OCT3/4) were performed. Frequency of CSCs was analyzed using HALO® software. All results were divided and compared in 2 groups: FL pts with short-term survival (less than 5 years) and long-term survival (more than 20 years). Unpaired Student’s t-test was used for statistical analysis in these groups. Results There were 26 (44.1%) pts with short-term survival and 33 (55.9%) FL pts with long-term survival in our studied patients. There was no difference in the frequencies of CD20+ cells in the short-term and long-term survival groups (p > 0.05). However, a significant increase in the frequencies of single CSC markers (ABCG2, Ki67, or OCT3/4) as well as CSC combination markers (ABCG2+Ki67+OCT3/4+) was found in the short-term survival group compared to the long-term group (all with p values < 0.05). Conclusion Short-term survival FL pts demonstrated higher expression of CSC markers in their lymph node biopsies, indicating their prognostic value in distinguishing FL patients at the highest risk of disease and worse outcome, and providing a guide for more effective therapy in FL. Funding Source Ladies Leukemia League Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)