Peter G Alexander1, Donald C McMillan2, James H Park2. 1. School of Medicine, University of Glasgow, Glasgow, United Kingdom. Electronic address: p.alexander.1@research.gla.ac.uk. 2. School of Medicine, University of Glasgow, Glasgow, United Kingdom.
Abstract
BACKGROUND: PD-1 checkpoint inhibitors are novel therapeutic agents in colorectal cancer (CRC). Immunohistochemical staining for CD274 assessment is standardised in upper GI cancer, but not in CRC. METHODS: Methodologies of relevant studies were scrutinized and meta-analysis of survival and CD274/PDCD1 performed. Furthermore, anti-PD-1 therapy clinical trial results in CRC were assessed with particular emphasis on CD274 assessment. RESULTS: 24 studies were included. CD274 on immune cells was associated with good prognosis. CD274 on tumour cells has heterogenous outcomes and does not meet requirements of a prognostic marker. As a marker of response to anti-PD-1 therapy, CD274 assessment is not standardised in CRC. CONCLUSION: CD274 does not appear useful as a prognostic marker. As a marker of response to anti-PD-1 therapy, assessment methodology requires standardisation. As the Combined Positive Score (CPS) is used in upper GI cancer, this seems a logical method to adopt. Thresholds for CRC remain to be determined.
BACKGROUND:PD-1 checkpoint inhibitors are novel therapeutic agents in colorectal cancer (CRC). Immunohistochemical staining for CD274 assessment is standardised in upper GI cancer, but not in CRC. METHODS: Methodologies of relevant studies were scrutinized and meta-analysis of survival and CD274/PDCD1 performed. Furthermore, anti-PD-1 therapy clinical trial results in CRC were assessed with particular emphasis on CD274 assessment. RESULTS: 24 studies were included. CD274 on immune cells was associated with good prognosis. CD274 on tumour cells has heterogenous outcomes and does not meet requirements of a prognostic marker. As a marker of response to anti-PD-1 therapy, CD274 assessment is not standardised in CRC. CONCLUSION:CD274 does not appear useful as a prognostic marker. As a marker of response to anti-PD-1 therapy, assessment methodology requires standardisation. As the Combined Positive Score (CPS) is used in upper GI cancer, this seems a logical method to adopt. Thresholds for CRC remain to be determined.