PD-L1 Testing In Metastatic Triple Negative Breast Cancer: Results Of An Italian Survey

Background: Immunotherapy has revolutionized the approach to metastatic triple-negative breast cancers (mTNBC). Atezolizumab was approved for patients with mTNBC whose tumours express PD-L1, determined by SP 142 assay. To assess the availability and practice of SP142 test we administered a survey to all the 15 Pathology Departments of the Lazio Region during a 6-months period.Methods: The survey comprised 12 questions regarding the availability of SP142 in the Pathology Departments, the percentage of positive tests, the difficulties of pathologists in case close to cut-off value and the tested samples.Results: The SP142 assay was available only in 8 Centers. In case of positive result, most Centers (5/8, 62.5%) reported values of PD-L1 expression ranging from > 1 to Conclusion: Our results raise some important issues concerning the evaluation of PD-L1 in the “real-life” setting, providing strategies for its implementation.