Interobserver variation of PD-L1 SP142 immunohistochemistry interpretation in breast carcinoma: A study of 79 cases using whole slide imaging Journal Article
| Authors: | Hoda, R. S.; Brogi, E.; D'Alfonso, T. M.; Grabenstetter, A.; Giri, D.; Hanna, M. G.; Kuba, M. G.; Murray, M. P.; Vallejo, C. E.; Zhang, H.; Reis-Filho, J. S.; Wen, H. Y. |
| Article Title: | Interobserver variation of PD-L1 SP142 immunohistochemistry interpretation in breast carcinoma: A study of 79 cases using whole slide imaging |
| Abstract: | Context.-The Ventana programmed death ligand-1 (PD-L1) SP142 immunohistochemical assay (IHC) is approved by the US Food and Drug Administration as the companion diagnostic assay to identify patients with locally advanced or metastatic triple-negative breast cancer for immunotherapy with atezolizumab, a monoclonal antibody targeting PD-L1. Objective.-To determine interobserver variability in PD-L1 SP142 IHC interpretation in invasive breast carcinoma. Design.-The pathology database was interrogated for all patients diagnosed with primary invasive, locally recurrent, or metastatic breast carcinoma on which PD-L1 SP142 IHC was performed from November 2018 to June 2019 at our institution. A subset of cases was selected using a computerized random-number generator. PD-L1 IHC was evaluated in stromal tumor-infiltrating immune cells using the IMpassion130 trial criteria, with positive cases defined as immunoreactivity in immune cells in 1% or more of the tumor area. IHC was interpreted on whole slide images by staff pathologists with breast pathology expertise. Interobserver variability was calculated using unweighted kappa. Results.-A total of 79 cases were assessed by 8 pathologists. Interobserver agreement was substantial (kappa = 0.727). There was complete agreement among all 8 pathologists in 62% (49 of 79) of cases, 7 pathologists or more in 84% (66 of 79) of cases, and 6 pathologists or more in 92% (73 of 79) of cases. In 4% (3 of 79) of cases, all of which were small biopsies, pathologists' interpretations were evenly split between scores of positive and negative. Conclusions.-The findings show substantial agreement in PD-L1 SP142 IHC assessment of breast carcinoma cases among 8 pathologists at a single institution. Further study is warranted to define the basis for discrepant results. |
| Keywords: | microscopy; cancer |
| Journal Title: | Archives of Pathology & Laboratory Medicine |
| Volume: | 145 |
| Issue: | 9 |
| ISSN: | 0003-9985 |
| Publisher: | College of American Pathologists |
| Date Published: | 2021-09-01 |
| Start Page: | 1132 |
| End Page: | 1137 |
| Language: | English |
| ACCESSION: | WOS:000695281500014 |
| DOI: | 10.5858/arpa.2020-0451-OA |
| PROVIDER: | wos |
| PUBMED: | 33417715 |
| Notes: | Article -- Source: Wos |
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
Related MSK Work