system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Aged, Antineoplastic Agents, Biopsy, Capecitabine, Chemoradiotherapy, Adjuvant, Deoxycytidine, Female, Fluorouracil, Humans, Male, MicroRNAs, Microarray Analysis, Middle Aged, Neoadjuvant Therapy, Organoplatinum Compounds, Oxaliplatin, RNA, Neoplasm, Rectal Neoplasms, Rectum, Reverse Transcriptase Polymerase Chain Reaction, Sensitivity and Specificity.
user
Does a specific miRNA signature correlate with complete pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer? Context: MicroRNAs (miRNAs) are small, noncoding RNA molecules that can be down- or upregulated in colorectal cancer and have been associated to prognosis and response to treatment. We studied miRNA expression in tumor biopsies of patients with rectal cancer to identify a specific "signature" correlating with pathological complete response (pCR) after neoadjuvant chemoradiotherapy. A total of 38 T3-4/N+ rectal cancer patients received capecitabine-oxaliplatin and radiotherapy followed by surgery. Pathologic response was scored according to the Mandard TRG scale. MiRNA expression was analyzed by microarray and confirmed by real-time Reverse Transcription Polymerase Chain Reaction (qRT-PCR) on frozen biopsies obtained before treatment. The correlation between miRNA expression and TRG, coded as TRG1 (pCR) vs. TRG >1 (no pCR), was assessed by methods specifically designed for this study. Microarray analysis selected 14 miRNAs as being differentially expressed in TRG1 patients, and 13 were confirmed by qRT-PCR: 11 miRNAs (miR-1183, miR-483-5p, miR-622, miR-125a-3p, miR-1224-5p, miR-188-5p, miR-1471, miR-671-5p, miR-1909∗, miR-630, miR-765) were significantly upregulated in TRG1 patients, 2 (miR-1274b, miR-720) were downexpressed. MiR-622 and miR-630 had a 100% sensitivity and specificity in selecting TRG1 cases.
assistant
A set of 13 miRNAs is strongly associated with pCR and may represent a specific predictor of response to chemoradiotherapy in rectal cancer patients. Final Decision: yes