John Haanen, MD PhD, epartment of Medical Oncology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, discussed the role of PD-L1 as a biomarker in lung cancer.
John Haanen, MD PhD, department of Medical Oncology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, discusses the role of PD-L1 as a biomarker in lung cancer.
PD-L1 expression can be very dynamic, says Haanen. Therefore, PD-L1 expression may appear to be different depending on when the test was conducted.
PD-L1 expression of tumor cells or within the tumor microenvironment can be induced by the interaction between the immune system, T-cells, and the tumor. T-cells are activated when they recognize the tumor, a process which can sometimes induce PD-L1 expression, explains Haanen. This does not necessarily mean that PD-L1 is expressed all the time. Because PD-L1 is not always present in the tumor, it is not a reliable biomarker, says Haanen.
There does appear to be an association between outcomes and PD-L1 expression, especially with the PD-L1-directed agents; however it is not clear-cut, and therefor should not be used as a biomarker at this time in lung cancer, says Haanen.