Abstract 353P
Background
Tertiary lymphoid structures (TLS) are organized aggregations of immune cells under pathological conditions. However, the presence and predictive value of TLS heterogeneity in maturation and spatial location in prostate cancer (PCa) remains unknown.
Methods
Immunohistochemistry and multispectral fluorescence techniques were used to assess the heterogeneity of TLS and the characteristics of TME cell infiltration. The prognostic impact of TLS heterogeneity was thoroughly investigated in 701 prostate cancer patients from TCGA and Fudan University Shanghai Cancer Center cohorts. The relationship between TLS heterogeneity and immunoreactivity or malignancy of PCa was assessed by quantifying immune cell infiltration.
Results
In PCa, TLS is predominantly found within the tumor, and patients with positive intratumoral TLS (intra-TLS) have a longer disease-free survival interval and progression-free interval. The maturity of peritumoral TLS (peri-TLS) was lower than that of intra-TLS, and Treg infiltration was significantly increased, suggesting an immunosuppressive role of the tumor microenvironment. Interestingly, multispectral fluorescence immunohistochemistry and immunofluorescence were also suggestive of high PDL1 expression, more Tregs and less high endothelial venules in the vicinity of immature TLS.
Conclusions
This study reveals the predictive value of differences in spatial heterogeneity and maturity of TLS in relation to the clinical features as well as prognosis of PCa. It provides new ideas for the selection of future PCa immunotherapy population.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Fudan University Shanghai Cancer Center.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.