Serum miR-143 levels predict the pathological response to neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

// Yukiharu Hiyoshi 1 , Takashi Akiyoshi 1 , Ramu Inoue 2 , Keiko Murofushi 3 , Noriko Yamamoto 4 , Yosuke Fukunaga 1 , Masashi Ueno 1 , Hideo Baba 5 , Seiichi Mori 6 and Toshiharu Yamaguchi 1 1 Gastroenterological Center, Department of Gastroenterological Surgery, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan 2 Clinical Research Center, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan 3 Department of Radiation Oncology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan 4 Division of Pathology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan 5 Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan 6 Division of Cancer Genomics, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan Correspondence to: Takashi Akiyoshi, email: takashi.akiyoshi@jfcr.or.jp Keywords: rectal cancer, chemoradiotherapy, serum, miR-143, prediction Received: January 10, 2017 Accepted: March 22, 2017 Published: March 31, 2017 ABSTRACT Recently, several circulating miRNAs have been reported as promising, minimally invasive biomarkers for the diagnosis or prediction of the prognosis in various types of cancer. However, the utility of circulating miRNAs as predictive markers of the cancer response to neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer is still unclear. To identify circulating serum miRNAs useful for predicting a pathological good response to nCRT, total 18 serum miRNAs of interest were analyzed by real-time polymerase chain reaction in 94 rectal cancer patients treated with nCRT and surgery. Pathological complete response (pCR; Dworak TRG4) and near-pCR (TRG3) were obtained in 12 (13%) and 9 (9%) patients respectively, and we regarded them as nCRT-responders. Of the 18 serum miRNAs, only the serum level of miR-143 was identified significantly associated with a pathological response to nCRT in 94 patients; the serum miR-143 level was significantly lower in nCRT-responders than in non-responders. A multivariate analysis incorporating other clinicopathological factors showed that only the serum miR-143 level was an independent predictor of a good pathological response. The circulating serum miR-143 level may be a novel, non-invasive predictive marker of a response to nCRT in locally advanced rectal cancer patients.