Key clinical point: Programmed cell death-1 ligand-2 (PD-L2) protein levels were high in approximately one-third of estrogen receptor-positive (ER+) breast cancer (BC) tumors and were associated with greater odds of disease recurrence.
Major finding: High levels of PD-L2 protein were present in 33% of ER+ tumors and were associated with shorter progression-free survival in the entire cohort of patients with ER+ BC (hazard ratio [HR] 2.0; P < .001) and in the subgroup of patients treated with adjuvant chemotherapy (HR 3.4; P < .001).
Study details: Findings are from a retrospective study including patients with ER+ BC who were categorized into the main study cohort (n = 684) and the external validation cohort (n = 273).
Disclosures: This study was supported by grants from Susan G. Komen, US National Institutes of Health, and other sources. The authors declared serving in leadership, employment, or consulting or advisory roles or receiving funding, honoraria, or travel and accommodation expenses from several sources.
Source: Chervoneva I et al. High PD-L2 predicts early recurrence of ER-positive breast cancer. JCO Precis Oncol. 2023;7:e2100498 (Jan 18). Doi: 10.1200/PO.21.00498