Developing a radiosensitivity gene signature for Caucasian patients with breast cancer.

Adjuvant radiotherapy is an important clinical treatment option for patients with breast cancer. However, for Caucasian patients, the clinical benefit of adjuvant radiotherapy can differ from African‑American patients with respect to the overall survival. The goal of the current study was to develop a gene signature and to pre‑identify patients likely to benefit from radiotherapy. Using publicly available breast cancer data from The Cancer Genome Atlas, a new cross‑validation procedure was proposed for developing a gene signature and predicting radiosensitive patients. The results demonstrated that the predicted radiosensitive patients who received radiotherapy exhibited a significantly better survival, while the effect of radiotherapy was not significant for predicted non‑radiosensitive patients. Further hierarchical cluster analysis revealed that the predicted sensitivity for each patient corresponded closely to the results of the cluster analysis. Collectively, the findings of the current study demonstrated that a radiosensitive molecular signature can be used to identify radiosensitive Caucasian patients with breast cancer.