Characteristics and related factors of expression of programmed death ligand-1 in grade Ⅲ non-special type invasive breast cancer / 肿瘤研究与临床

ABSTRACT

Objective:To explore the expression of programmed death ligand-1 (PD-L1) protein in grade Ⅲ non-special type invasive breast cancer and its related factors, so as to provide a basis for immunotherapy.Methods:A total of 63 surgically resected specimens of grade Ⅲ non-special type invasive breast cancer diagnosed by pathology in Cancer Hospital & Shenzhen Hospital of Chinese Academy of Medical Sciences from February 2017 to February 2021 were collected. The HE-stained sections were reviewed, and the proportion of immune cells (IC) in all invasive active tumor cells in the tumor sections was calculated. The expression of PD-L1 (SP142) protein in all specimens was detected by immunohistochemistry. The relationship between the positive expression of PD-L1 protein and the clinicopathological parameters was analyzed, and the Pearson correlation test was used to analyze the relationship between the expression of PD-L1 (SP142) and the degree of IC infiltration.Results:Among 63 patients, 19 patients (30.2%) were triple-negative type, 34 patients (53.9%) were luminal type, and 10 patients (15.9%) were human epidermal growth factor receptor 2 (HER2) overexpression type. The positive rate of PD-L1 (SP142) in grade Ⅲ non-special type invasive breast cancer was 77.8% (49/63). The positive rate of PD-L1 (SP142) in triple-negative type was 94.7% (18/19), the positive rate in non-triple-negative type was 70.5% (31/44), and the difference between the two groups was statistically significant ( P = 0.047). The positive rate of PD-L1 (SP142) in estrogen receptor (ER)-negative patients or progesterone receptor (PR)-negative patients was both 90.3% (28/31), which was higher than that of ER-positive patients or PR-positive patients (65.6%, 21/32), and the difference was statistically significant ( P = 0.018); the positive rate of PD-L1 (SP142) was not related to the patient's age, tumor site, tumor maximum diameter and number, vascular tumor thrombus, nerve invasion, lymph node metastasis, HER2 status and Ki-67 positive index (all P > 0.05). The expression of PD-L1 was positively correlated with the degree of IC infiltration ( r = 0.716, P<0.001). Conclusion:In grade Ⅲ non-special type invasive breast cancer, the patients with triple-negative type has a high positive rate of PD-L1, and the patient with negative ER or PR has a high positive rate of PD-L1; the tumor IC infiltration is positively correlated with the expression of PD-L1.