The aim of this study was to identify Artemis as a predictive biomarker for guiding preoperative chemoradiotherapy in locally advanced rectal cancer. The resection specimens were collected from 50 patients with rectal cancer who underwent preoperative chemoradiotherapy. Artemis expression in biopsy tissues was evaluated using immunohistochemical staining according to the percentage of positively stained cells combined with staining intensity. Among the 50 patients, 36 (72%) had a weakly positive Artemis protein expression, 10 (20%) had a moderately positive expression, and 4 (8%) showed a strongly positive expression. The criteria of magnetic resonance imaging tumor regression grade (mrTRG) and pathological rectal cancer regression grade (RCRG) were used to assess the tumor response to chemoradiotherapy. Correlation analysis shows that there is a significant negative correlation between high Artemis immunoscore and treatment response (r = -0.532, p < 0.001). The results imply that high Artemis expression was associated with poor treatment response. Our study suggested a potential role of Artemis as a predictive biomarker of the tumor response to preoperative chemoradiotherapy in patients with locally advanced rectal cancer.
Keywords: Artemis; preoperative chemoradiotherapy; radioresistance; rectal cancer.