[Prophylactic nodal radiotherapy for breast cancer]

Anti-PD-L1 Antibody Enhances T Cell Immune Responses and Reduces Resistance of Breast Cancer Cells to Radiotherapy

Immune escape is a frequent occurrence, which limits the duration of antitumor immune responses to radiotherapy. Here, we aimed to ascertain the roles and underlying mechanisms of programmed death ligand 1 (PD-L1) in tolerance of breast cancer (BC) to radiotherapy. We first quantified microRNA-21 (miR-21) and PD-L1 expression in BC tissues and cells, followed by identification of the interactions between miR-21, PD-L1, and programmed cell death protein 4 (PDCD4). miR-21 knock-in mice were used to construct tumor-bearing models, which were then treated with anti-PD-L1 antibody and irradiation, followed by measurement of tumor growth and tumor immune escape. Finally, we evaluated the synergistic effects of radiotherapy and anti-PD-L1 antibody in vivo. The results showed increased miR-21 expression in BC tissues and cells, which was positively correlated with PD-L1 expression. The treatment with radiotherapy or anti-PD-L1 antibody in the miR-21 knock-in mice diminished tumor weight and volume, along with decreased CD3⁺CD8⁺ positive cells, serum IL-2 and IFN-γ levels, and lower PD-L1 expression, but augmented apoptosis of T and BC cells. Moreover, miR-21 significantly augmented PD-L1 expression via PI3K/Akt pathway activation by targeting PDCD4 in BC cells. Thus, radiotherapy and anti-PD-L1 antibody synergistically accelerated the therapeutic effect against BC in mice, thereby implicating a close interplay between radiotherapy, T cells, and the miR-21/PDCD4/PI3K/Akt/PD-L1 axis.

Effect of Prophylactic Radiotherapy on Patients with Stage II-III Esophageal Cancer after Esophageal Cancer Radical Operation and Influencing Factors in Its Recurrence

Objective

To explore the effect of prophylactic radiotherapy on patients with stage II-III esophageal cancer (EC) after esophageal cancer radical operation (ECRO) and influencing factors on EC recurrence.

Methods

Totally, 65 patients with EC in our hospital were enrolled. Among them, 30 patients were treated by routine ECRO as a control group (Con group) and 35 patients by prophylactic radiotherapy as a research group (Res group). Then, the following measures were taken: record the efficacy on both groups, quantify their C-reactive protein (CRP) and white blood cell count (WBC) before and after therapy, evaluate their mental state through the revised piper fatigue scale (PFS-R) before and after therapy, determine their changes in Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS) before and after therapy, compare them in terms of lymph-node metastatic rate (LNMR), hematogenous metastasis rate (HMR), anastomotic recurrence rate (ARR), and 3-year survival rate, compare them in terms of life quality after therapy via the Quality of Life-Core Questionnaire (QLQ-C30), and analyze influencing factors on their recurrence.

Results

The Res group showed a notably higher total effective rate (TER) than the Con group (P=0.037). After therapy, CRP and WBC in both groups increased, but their levels were not considerably different in both (P > 0.05). Additionally, after therapy, in contrast to the Con group, the Res group got notably lower PFS-R, SDS, and SAS scores, showed notably lower LNMR and ARR and notably higher 3-year survival rate, and experienced notably higher life quality (all P < 0.05), and the HMR results were not considerably different in both groups (P > 0.05). Moreover, carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), esophageal inflammation history, family medical history, postoperative complications, and lymphatic and vascular infiltration were risk factors for the disease recurrence, and treatment method was the protective factor for it.

Conclusion

For patients with stage II-III EC after ECRO, prophylactic radiotherapy is highly effective and safe and can lower the recurrence rate, so it is worth popularizing in clinical practice.