Biomarker testing is used to drive treatment decisions in an approach known as personalised medicine to ensure each patient receives the most appropriate treatment for their cancer
The goal of biomarker testing is to inform treatment decisions for optimal outcomes
The spectrum of bladder cancer is diverse1
Urothelial bladder cancer can present with divergent differentiation patterns that include squamous, glandular, micropapillary, nested, lymphoepithelioma-like, plasmacytoid and sarcomatoid variants1 differentiated by pathological and biomarker analysis2
Advanced bladder cancer occurs when the cancer has spread to 1 or more lymph node within the pelvis or has metastasised to the lungs, bones or liver3
While the list of biomarkers for prognosis and treatment selection for advanced bladder cancer is growing, their clinical relevance remains unclear due to lack of external validation in external datasets4
PD-L1, an immune checkpoint ligand, is a potential biomarker expressed in many immunogenic cancers, including bladder cancer
The potential for immune responses are increased in tumours with high rates of somatic mutations5
Tumours can evade detection by the immune system by co-opting inhibitory checkpoint pathways that suppress antitumour immune responses, such as PD-1, PD-L1 and CTLA-46
Many tumours achieve this through overexpression of PD-L17
PD-L1 expression is measured across a continuum from no/low expression through moderate and high expression
Unlike some other diagnostic biomarkers used in the oncology setting, PD-L1 expression does not provide a binary result such as positive/negative or mutated/wild type7,8
Determining tumour PD-L1 expression status may help identify patients more likely to respond to immunotherapy-based treatment regimens5
There is emerging evidence to suggest that PD-L1 can inform clinical decision-making7
CTLA-4, cytotoxic T-lymphocyte-associated antigen-4; PD-1, programmed cell death-1; PD-L1, programmed cell death ligand-1; QoL, quality of life
REFERENCES
Chalasani V, et al. Can Urol Assoc J 2009;3(6 Suppl. 4):S193–8
