Abstract 1155: Serum microRNA-21 is a novel biomarker in patients with esophageal squamous cell carcinoma

Abstract

Abstract Backgrounds and objective: Esophageal squamous cell carcinoma (ESCC) is one of the most difficult malignancies to be cured among gastrointestinal tract cancers. Recently, it was revealed that microRNAs stably exist in serum and may affect pathogenesis of several diseases. However, there are only a few reports that have demonstrated the significance of microRNA (mir) in the serum of patients with ESCC. Accordingly, the aims of this study were to clarify the status of mir-21 in the serum of ESCC patients and to reveal the usefulness of this molecule as a biomarker. Patients and methods: Serum samples were obtained from 52 patients diagnosed with ESCC, as well as from 17 “control” patients diagnosed with gallstones, without active inflammation, in Kumamoto University Hospital from 2008 to 2010. Pre-treatment serum samples were collected during diagnostic studies. Thirty-two ESCC patients received induction chemotherapy using the Docetaxel/ cisplatin /5-Fluorouracil (DCF) regimen (60 mg/m2 Docetaxel on day 1; 350 mg/m2 5-Fluorouracil and 6 mg/m2 cisplatin on days 1-5; 2 courses) after being diagnosed with node-positive ESCC. Twenty-four pairs of serum samples before and after chemotherapy were collected. The expression of miR-21 was determined by qRT-PCR using TaqMan microRNA assay Kits® (Applied Biosystems, USA). Results: The results of qRT-PCR analysis indicated that the ESCC patients had significantly higher levels of serum miR-21 than the control patients (P = 0.007). The value of area under the receiver operating characteristic curve was 0.885 for microRNA-21. When the patients were divided into two groups according to tumor size (≥40mm vs. <40mm), we found that the patient group with the larger tumors exhibited significantly higher levels of miR-21 than the patients with small-sized tumors. We examined the expression levels of miR-21 in the paired (pre- and post-therapy) serum samples of 24 patients who were treated with chemotherapy. The miR-21 expression levels in the patients’ post-chemotherapy samples were significantly reduced compared to the corresponding levels in the pre-chemotherapy samples (P=0.009). When the patient response to cancer chemotherapy was evaluated by RECIST v. 1.0, we found a significant decrease in the miR-21 expression levels in the Complete Response /Partial Response patients, whereas no significant decrease occurred in the levels in Stable Disease/ Progressive Disease patients (P = 0.003 versus N.S). Conclusion:Serum microRNA-21 is considered to be a novel biomarker for diagnosing ESCC, and it can also be used as a response marker during chemotherapy for ESCC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1155. doi:10.1158/1538-7445.AM2011-1155