High Plasma TIMP-1 and Serum CEA Levels during Combination Chemotherapy for Metastatic Colorectal Cancer Are Significantly Associated with Poor Outcome

Objective: To evaluate whether combination chemotherapy leads to early changes in plasma TIMP-1 and serum carcinoembryonic antigen (CEA) levels in patients with metastatic colorectal cancer (mCRC), and whether such changes relate to subsequent objective response, time to progression (TTP) and overall survival. Materials and Methods: Eighty-eight patients with mCRC were included. Blood samples were collected before initiation and after 2, 4 and 6 weeks of treatment with an irinotecan-5-fluorouracil combination. Plasma TIMP-1 and serum CEA levels were determined by validated ELISA platforms. The first response evaluation was performed after 8 weeks of chemotherapy. Results: Median plasma TIMP-1 and serum CEA levels did not change significantly during 6 weeks of treatment. High plasma TIMP-1 and high serum CEA levels before treatment and at weeks 2, 4 and 6 were related to poor objective response. Moreover, high levels of plasma TIMP-1 before treatment and at weeks 2 and 4 were significantly associated with short TTP, while high levels of serum CEA at week 4 were significantly associated with short TTP. Finally, high levels of plasma TIMP-1 before and during treatment were significantly associated with poor overall survival; p <0.0001 in all 4 determinations. A similar association between serum CEA and overall survival could only be demonstrated before treatment. Conclusion: Median plasma TIMP-1 or serum CEA levels do not change significantly during the first 6 weeks of chemotherapy for mCRC. The results indicate that plasma TIMP-1 in particular and serum CEA may be valuable biomarkers even in samples collected during treatment with chemotherapy.