Chemoradiation-induced Changes in Serum CEA and Plasma TIMP-1 in Patients with Locally Advanced Rectal Cancer

Preoperative biomarkers serum CEA and plasma TIMP-1 have been shown to have prognostic and predictive value in patients with colorectal cancer. The aim of the present study was to evaluate the possible impact of chemoradiotherapy (CRT) on preoperative biomarker levels in patients with rectal cancer. Thirty-three patients with rectal cancer were prospectively included. The patients received CRT for 6-8 weeks. Blood samples were collected before CRT (pre-CRT) and preoperatively (post-CRT). Median CEA was 3.5 (range 0.6-36.1) μg/l and 2.4 (range 0.0-10.2) μg/l (p=0.002) and median plasma TIMP-1 was 132.1 (range 77.8-342.7) μg/l and 140.0 (range 82.6-440.9) μg/l (p=0.04) in the pre- and post-CRT measurements, respectively. CRT induced a significant decrease in serum CEA and increase in plasma TIMP-1 levels. Therefore, the preoperative biomarker levels may be affected by treatments received before blood sample collection. Translation of results of preoperative biomarkers needs to take such facts into consideration.