Bisgin et al. BMC Cancer 2012, 12:58 http://www.biomedcentral.com/1471-2407/12/58 R E S E A R C H A R T I C L E Open Access Increased serum sTRAIL levels were correlated with survival in bevacizumab-treated metastatic colon cancer Atil Bisgin1*, Aysegul Kargi2, Arzu D Yalcin3, Cigdem Aydin1, Deniz Ekinci2, Burhan Savas2 and Salih Sanlioglu1 Abstract Background: Colorectal cancer is the third most common cancer and the third leading cause of cancer-related death. Bevacizumab is a humanized monoclonal antibody developed against vascular endothelial growth factor (VEGF) for the treatment of metastatic cancer. The parameters of RECIST (Response Evaluation Criteria for Solid Tumors) are not adequate to detect important treatment effects and response. Our goal was to evaluate the possibility of using sTRAIL (serum-soluble TNF-related apoptosis-inducing ligand) and VEGF as markers of treatment efficacy and prognosis in patients with metastatic colon cancer. Methods: sTRAIL and VEGF levels were measured by ELISA in the sera of 16 bevacizumab-treated metastatic colon cancer patients and 10 presumably healthy age-matched controls. The measurements were taken before and after treatment for comparison purposes. Results: Elevated levels of sTRAIL were found in seven out of 16 patients after bevacizumab treatment. Although these patients had a median survival time of 20.6 months, the remaining bevacizumab-treated patients who did not show an increase in sTRAIL had a median survival time of 9.4 months. As expected, serum VEGF levels were decreased in all patients who received bevacizumab therapy and showed no correlation between serum VEGF levels and patient survival (data not shown). Conclusions: Serum sTRAIL levels might be a useful predictor of prognosis in metastatic colon cancer, in the early evaluation stages following bevacizumab treatment. Background Colorectal cancer is the third most common cancer and the second leading cause of cancer-related death [1]. Overall, the 5-year survival rate is <10% for stage IV cancer [2]. The cure rate with surgery alone is very low and chemotherapy and radiotherapy are usually needed in patients with untreated metastatic colon cancer. The development of colorectal cancer is characterized by a sequence of events during which normal colonic epithe- lium gradually transforms to carcinoma tissue, in most cases, via the development of colorectal adenomas [3]. This sequence of events is driven by an accumulation of molecular (epi)genetic alterations causing progressive disorders in cell growth, differentiation and apoptosis * Correspondence: atilbisgin@yahoo.co.uk 1Human Gene and Cell Therapy Center of Akdeniz University Hospitals and Clinics, Department of Medical Genetics, Antalya, Turkey Full list of author information is available at the end of the article [4,5]. Apoptosis, or programmed cell death, plays an important role in the development and maintenance of tissue homeostasis but also represents an effective mechanism by which abnormal cells, such as tumor cells, can be eliminated [6-8]. Abnormalities in apoptotic function or resistance to apoptosis have been identified as important events in the pathogenesis of colorectal cancer and its resistance to chemotherapeutic drugs and radiotherapy [9,10]. In recent years, bevacizumab, a novel humanized monoclonal antibody directed against vascular endothe- lial growth factor (VEGF) has found widespread clinical use as an angiogenesis inhibitor for certain types of metastatic cancers [11]. Treatment with bevacizumab with/without the combination of other chemotherapeu- tic agents inhibits VEGF receptor activation and vascular permeability, which eventually lead to tumor cell apop- tosis [12,13]. Apoptosis can be induced passively, © 2012 Bisgin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.