Discordance of PD-L1 status between primary and metastatic breast cancer: A systematic review and meta-analysisShow others and affiliations
2021 (English)In: Cancer Treatment Reviews, ISSN 0305-7372, E-ISSN 1532-1967, Vol. 99, article id 102257Article, review/survey (Refereed) Published
Abstract [en]
INTRODUCTION: Programmed cell death ligand 1 (PD-L1) expression is predictive for benefit from immunotherapy in several human malignancies including triple negative breast cancer. Lower positivity rates but a larger relative benefit from atezolizumab has been implied when PD-L1 status is assessed at metastatic sites. We aimed to study the discordance of PD-L1 expression between primary tumor and metastasis in breast cancer due to its potential clinical utility.
METHODS: Cochrane Library, Embase, Medline and Web of science were searched for studies reporting on PD-L1 expression in primary and metastatic breast cancer, followed by data extraction. Outcomes included pooled PD-L1 positivity rates in tumor cells, immune cells or both in primary tumor and metastasis, PD-L1 discordance between matched primary tumors and metastasis and direction of discordance.
RESULTS: Of 2552 identified entries following de-duplication, 20 studies fulfilled the predefined inclusion criteria. Pooled PD-L1 positivity rate was higher in primary tumors compared to metastasis when assessed in immune cells (51.2% vs 37.1% p < 0.001) and tumor/immune cells (30.1% vs 14.6% p < 0.001), but not in tumor cells (18.7% vs 17.8% p = 0.65). PD-L1 positivity was lowest when assessed in bone metastases (12%) and highest in lymph nodes (60%). Discordance between primary tumors and metastasis was bidirectional, with higher pooled discordance rates when PD-L1 expression was assessed in immune compared to tumor cells (39.5% vs 13.6%, p < 0.001).
CONCLUSION: The observed considerable discordance between PD-L1 status in primary and metastatic breast cancer emphasizes the importance of appropriate tissue sampling when selecting patients for immunotherapy.
Place, publisher, year, edition, pages
Elsevier, 2021. Vol. 99, article id 102257
Keywords [en]
Breast cancer, Discordance, Immunotherapy, Metastasis, PD-L1
National Category
Cancer and Oncology
Identifiers
URN: urn:nbn:se:oru:diva-93451DOI: 10.1016/j.ctrv.2021.102257ISI: 000693067900017PubMedID: 34237488Scopus ID: 2-s2.0-85109147784OAI: oai:DiVA.org:oru-93451DiVA, id: diva2:1584537
Funder
Region Stockholm, K 2017-4577Swedish Cancer Society, CAN 2017/1043The Cancer Research Funds of RadiumhemmetSwedish Research CouncilEuropean CommissionKnut and Alice Wallenberg Foundation2021-08-122021-08-122021-09-17Bibliographically approved