View article

Background

Pancreatic Ductal Adenocarcinoma (PDAC) is considered a cold tumour and immune checkpoint inhibitors have proved unsuccessful thus far. Despite this there is variability in the number of intratumoral CD8+ T cells across the malignant epithelium and the microenvironment (TME).

Methods

We evaluated CD8 staining in FFPE sections in an unselected subset of patients enrolled on the COMPASS trial. Immunohistochemical staining was performed using the antibody CD8-4B11-L-CE. Tumoural regions were reviewed and annotated by a pathologist and digital image analysis (QuPath) enumerated the number of positive cells per mm 2. Samples were classified as CD8 hi vs CD8 lo using the median no./mm 2. Fisher’s exact test, student’s t-test and Mann Whitney test were used to explore associations; Kaplan Meier analyses evaluated impact on OS. Clinical and molecular data were integrated into …