Expression of PD-L1 in triple negative breast cancer

Abstract

Introduction: The second leading cause of cancer deaths in women is breast cancer. Breast cancer awareness has increased due to mammography screenings. The aim of study is to evaluate the prevalence of PD-L1 expression in TNBC cases and to correlate it with clinicopathological parameters. Method: PDL1 expression is measured by immunohistochemical technique using Dako kits, PD-L1 IHC 22C3 pharm Dx, on 44 paraffin block samples from Duhok municipal labs. If the specimen has a combined positive score (CPS) of 10 or higher, it expresses PD-L1. Age groups, grades, kinds, stages, and PDL1, lymph node involvement are studied. Results: 44 cross-sectional patients, mean and SD (47.7±14) years old. (54.5%) of patients in middle age group, (63.6%) at grade III, majority (88.6%) have IDC type and (75%) have negative PDL1, (63.6%) have KI69 less than 20, (70.5%) at stage T2, and (45.5%) have N1 lymph node involvement. There is significant association between PDL1 and Ki67, (100%) of patients with positive PDL1 have Ki67 more than 20 while (15.2%) of patients with negative PDL1 have Ki67 more than 20. Conclusion: 75% of middle-aged individuals with grade III had negative PDL1. All PDL1-positive patients have Ki67 above 20. Different research employ 1%, 5%, or 10% cutoff values, which affects PDL1.