Epidermal growth factor receptor expression and adjuvant chemoradiotherapy in rectal cancer Epidermal growth factor recepto in operated rectal cancer

Aim: Epidermal Growth Factor Receptor (EGFR) is a trans-membrane protein with tyrosine kinase activity and is expressed in 25-80% of colon cancer cases. EFGR expression is prognostic in patients with metastatic colorectal cancer, and anti-EGR- based therapies are routinely used in the treatment of patients with metastatic colorectal cancer. To the best of our knowledge, the relationship between EGFR expression and prognosis in directly operated patients who did not receive neoadjuvant treatment and subsequently received chemo-radiotherapy is unknown. Therefore, we retrospectively evaluated patients with stage 3 rectal cancer who underwent surgery without any preoperative treatment in our center and aimed to investigate the relationship between EGFR expression and prognosis in patients who received adjuvant chemoradiotherapy. Material and Methods: The data of patients who underwent surgery for rectal cancer and received chemoradiotherapy between 2010 and 2016 at Manisa State Hospital were retrospectively analyzed. Results: According to EGFR expression, it was 127.01 (95% CI, 85.43-168.59) months in the group with 10% less staining and 47.44 (95% CI, 26.77-68.12) months in the group with 10% or more staining. Lymphovascular invasion (p=0.032), perineural invasion (p=0.023), histologic grade (p=0.004) and EGFR expression percentage (p=0.005) were significantly associated with survival in multivariate analyses Discussion: The presence of 10% or more EGFR expression, LVI, PNI, and histological grade are significantly associated with survival in stage 3 rectal cancer patients who have undergone surgery and received postoperative chemotherapy. These markers can be used as prognostic biomarkers in the follow-up and treatment of these patients.