Serum levels of soluble programmed death protein 1 (sPD-1) and soluble programmed death ligand 1 (sPD-L1) in advanced pancreatic cancer
Kruger, S.; Legenstein, M-Louise.; Rösgen, V.; Haas, M.; Modest, D.Paul.; Westphalen, C.Benedikt.; Ormanns, S.; Kirchner, T.; Heinemann, V.; Holdenrieder, S.; Boeck, S.
Oncoimmunology 6(5): E1310358
2017
ISSN/ISBN: 2162-4011 PMID: 28638732 DOI: 10.1080/2162402x.2017.1310358
Accession: 060240467
Up to now, the efficacy of programmed death protein 1/programmed death ligand 1 (PD-1/PD-L1) blockade in pancreatic cancer (PC) remains uncertain. Serum levels of soluble PD-1 and PD-L1 (sPD-1/sPD-L1) have been reported to be independent prognostic factors in solid tumors susceptible to checkpoint blockade. Provenience, regulation and immunologic function of sPD-1 and sPD-L1 in cancer are poorly understood. To the best of our knowledge, sPD-1 and sPD-L1 have not been measured conjointly in any cancer type yet. In contrast to other tumor entities, sPD-1/sPD-L1 levels did not indicate an adverse outcome in a cohort of 41 patients with advanced PC. We observed a close positive correlation of sPD-L1 levels with sPD-1 in patients with advanced PC, suggesting a common provenience and regulation of sPD-1 and sPD-L1 in cancer patients. Higher sPD-L1 levels were present in patients with elevated C-reactive protein or strong tumoral T cell infiltration, while no correlation of sPD-L1 levels with tumoral PD-L1 expression was found. Our findings indicate that sPD-1 and sPD-L1 are markers of systemic inflammation in (pancreatic) cancer. In a subset of PC patients, elevation in sPD-L1 levels might be caused by an inflammatory tumor type - independent of tumoral PD-L1 expression.