263 Prognostic image-based quantification of CD8CD103 T cell subsets in high-grade serous ovarian cancer patients

Abstract

<h3>Introduction/Background*</h3> CD103-positive tissue resident memory-like CD8+ T cells (CD8CD103 TRM) are associated with improved prognosis across malignancies, including high-grade serous ovarian cancer (HGSOC). We investigated whether quantification of CD8, CD103 or both is required to improve existing survival prediction and whether all HGSOC patients or only specific subgroups of patients benefit from infiltration. <h3>Methodology</h3> We applied image-based quantification of CD8 and CD103 multiplex immunohistochemistry in the intratumoral and stromal compartments of 268 advanced-stage HGSOC patients from two independent clinical institutions. <h3>Result(s)*</h3> Infiltration denisty of CD8CD103 TRM was independent of clinicopathological factors and primary treatment strategy. A survival benefit of CD8CD103 TRM infiltration was observed in patients treated with primary cytoreductive surgery. Moreover, survival benefit in this group was limited to patients with no macroscopic tumor lesions after surgery (high epithelial CD8CD103 TRM infiltration 5 year survival 83% versus 52%, p=0.03; high stromal CD8CD103 TRM 5 year survival 77% versus 54%, p=0.01). No effect of CD8CD103 TRM infiltration on overall survival was observed in patients treated with neo-adjuvant chemotherapy, with or without macroscopic tumor lesions after surgery (high epithelial CD8CD103 TRM infiltration, p=0.77; high stromal CD8CD103 TRM infiltration, p=0.32). <h3>Conclusion*</h3> Our results suggest CD8CD103 TRM quantification as a superior method for prognostication compared to single CD8 or CD103 quantification, and supports the further exploration of image-based quantification of CD8CD103 TRM in HGSOC. This approach provides novel insights into prognostic stratification of HGSOC patients and may contribute to personalized treatment strategies in the future.