Recent data suggest that programmed death ligand 1 (PD-L1) expression may predict response to anti–programmed death 1 (PD-1) therapy. This retrospective observational study evaluated the prognostic effect of PD-L1+ expression in patients with histologically confirmed epithelial ovarian, primary peritoneal, or fallopian tube cancer (OCa).
Patients diagnosed with FIGO stages II-IV OCa from 2004-2012, at Aarhus University Hospital and Rigshospitalet, Copenhagen, Denmark, were included. PD-L1 expression was measured in tissue collected at OCa surgery, using immunohistochemistry with anti–PD-L1 22C3 antibody. PD-L1+ expression was defined as staining in ≥ 1% of tumor or inflammatory cells. Patients partially sensitive (PPS; treatment-free interval [TFI] of 6-12 mo) or fully sensitive (FPS; TFI >12 mo) to platinum therapy were considered platinum sensitive, whereas those refractory (TFI
Median age of the 376 patients at diagnosis was 63 years (range, 26-86). 77% had histologic grade 2/3 serous adenocarcinoma, 46% had residual tumor after surgery, and 9%, 70%, and 21% had FIGO stages II, III, and IV disease, respectively. FPS, PPS, platinum-resistant, and platinum-refractory disease comprised 49%, 27%, 15%, and 9% of patients, respectively. 50.5% of patients were PD-L1+, with prevalence increasing with increased platinum sensitivity (P for linear trend
PD-L1 was frequently expressed in advanced OCa patients, and expression may be prognostic, particularly in those with partially platinum-sensitive OCa.
Clinical trial identification
Legal entity responsible for the study
Merck & Co., Inc.
Merck & Co., Inc.
T.T. Vo: Employed by, own stock in, and have received research grants from Merck & Co., Inc. W. Zhou, M. Busch-Sørensen, D. Chappell: Employed by and own stock in Merck & Co., Inc. T. Steiniche: Received research funding from and have been reimbursed for travel and accommodation expenses by Merck & Co., Inc. All other authors have declared no conflicts of interest.