Radiotherapy Improves Antitumor Immunity by Inducing Immunogenic Cell Death in Breast Cancer Patients.

BACKGROUND

Radiotherapy, a significant cancer treatment, stimulates localized tumor cell death and causes immune modulation. Increasing data has indicated that radiation strengthens tumor-related immunity.

AIM OF THE STUDY: The aim of this work was to investigate the effect of radiotherapy on soluble forms of the primary immune checkpoints CTLA-4, PD-1 and PD-L1 in patients with breast cancer.

PATIENTS AND

METHODS

The study was conducted on70 subjects were separated into 2 groups: Group I included 40 patients with breast cancer who received fractionated radiation. Group II: Includes 30 healthy females free from any disease as control group, age and gender matched the patients' group. ELISA was used to assay CTLA-4, PD-1 and PD-L1.

RESULTS

The current study revealed that soluble PD-1 and PD-L1 are significantly elevated in sera of patients with breast cancer pre radiotherapy treatment and significantly higher than in control group. Exposure to radiotherapy significantly drops PD-1 levels and brings its levels in patients closer to those of healthy individuals but not affects PD-L1 levels. Soluble CTLA-4 is insignificantly elevated in sera of breast cancer patients pre radiotherapy treatment and significantly decreased post radiotherapy.

CONCLUSION

Radiotherapy can enhance immune recognition of the tumor cells by dropping the primary immune checkpoints PD-1 and CTLA-4 in breast cancer patients and improve response to immune checkpoints inhibition.