Abstract
Radiotherapy is the most important component of the comprehensive treatment of breast cancer, and immunocompromised patients respond with lower response rate. However, the role of programmed cell death protein-1, a critical immune molecule, in recurrence of breast cancer subjected to radiotherapy is unknown. A retrospective analysis was designed to explore the relevance. A number of 42 patients with early-stage breast cancer undergoing breast-conserving surgery and postoperative radiotherapy (18 recurrence and 24 nonrecurrence) were recruited, and clinical data were obtained. Immunohistochemistry was employed to detect programmed cell death protein-1, and Kaplan-Meier curves were used to analyze recurrence-free survival. The expression of programmed cell death protein-1 was higher in the recurrence group than recurrence-free group ( P < .05). Meanwhile, the recurrence-free mean survival was significantly longer in programmed cell death protein-1 low-expression group (68 months) than that in programmed cell death protein-1 high-expression group (56 months). In addition, the levels of T lymphocytes were obviously lower in patients with breast cancer than healthy group, and natural killer showed an opposite tendency. CD4(+) decreased significantly after 1 week radiotherapy and recovered rapidly 3 weeks after radiotherapy. Compared to recurrence-free group, the increment of T lymphocytes were inadequate in recurrence group. These experimental results indicated that the expression of programmed cell death protein-1 in tumor-infiltrating lymphocytes is related to immune disorder and recurrence of patients undergoing breast-preserving surgery and radiotherapy.