Tumor microRNAs Identified by Small RNA Sequencing as Potential Response Predictors in Locally Advanced Rectal Cancer Patients Treated With Neoadjuvant Chemoradiotherapy.

BACKGROUND/AIM: Rectal cancer accounts for approximately one-third of all colorectal cancers. Currently, the standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (CRT) with capecitabine or 5-fluorouracil followed by curative surgery. Unfortunately, only 20% of patients with LARC present complete pathological response after CRT, whereas in 20-40% cases the response is poor or absent. The aim of our study was to evaluate whether microRNAs (miRNAs) in tumor biopsy specimen have the potential to predict therapeutic response in LARC patients. PATIENTS AND METHODS: In total 87 LARC patients treated by CRT were enrolled in our prospective study. To identify predictive miRNAs, we used small RNA sequencing in 40 tumor biopsy samples of LARC patients (20 responders, 20 non-responders) and qPCR validation of selected miRNA candidates. RESULTS: In the discovery phase of the study, we identified 69 miRNAs to have significantly different expression between the group of responders (TRG 1,2) and a group of non-responders (TRG 4,5) to neoadjuvant CRT. Among these miRNAs, 48 showed a lower expression and 21 showed higher expression in tumor tissues from poorly responding LARC patients. Five miRNAs were selected for validation, but only miR-487a-3p was confirmed to have a significantly higher expression in the tumor biopsy specimens of non-responders to neoadjuvant CRT (p<0.0006, AUC=0.766). Gene Ontology (GO) clustering and pathway enrichment analysis of the miR-487a-3p mRNA targets, revealed potential mechanisms behind miR-487a-3p roles in chemoradioresistance (e.g. TGF-beta signaling pathway, protein kinase activity, double-stranded DNA binding, or microRNAs in cancer). CONCLUSION: By combination of miRNA expression profiling and integrative computational biology we identified miR-487a-3p as a potential predictive biomarker of CRT response in LARC patients.

C-reactive protein as predictor of anastomotic complications after minimally invasive oesophagectomy.

BACKGROUND: Anastomotic leaks after oesophagectomy with tabularised stomach replacement are a significant factor in post-operative mortality and morbidity. Early detection and treatment of this complication allow for improving operative and oncological results. When assessing laboratory values - elevation of inflammatory parameters - complicated interpretation is an issue (systemic inflammatory response syndrome, surgical versus non-surgical complication). Results studying the relationship between C-reactive protein (CRP) and complications following oesophagectomies are inconsistent. The aim of our work was to find relationships between the development of post-operative CRP values and the occurrence of anastomotic complications following minimally invasive oesophagectomy (MIE). MATERIALS AND METHODS: Analysis of the relationship between CRP values and the occurrence of anastomotic complications or the necessity of reoperation following oesophagectomy with tabularised stomach replacement and cervical anastomosis performed using thoracoscopy and laparoscopy in a group of patients operated on for malignancies at our department between 2012 and 2015. RESULTS: A significant difference was found in average CRP values on the 5th day and 7th day following operation between patients with and without leaks (233 mg/l vs. 122.8 mg/l P = 0.003, respectively 208.9 mg/l vs. 121.3 mg/l P = 0.014). However, on the 5th day, the leak was clinically apparent only in one case out of 11 leaks. A significant difference in CRP values on the 5th day was found between patients who needed revision surgery and patients without revision surgery (294 mg/l vs. 133.5 mg/l P = 0.01). CONCLUSIONS: Patients after MIE with tabularised stomach replacement and cervical anastomosis complicated by anastomotic leaks or with the necessity for reoperation had a significantly higher CRP values on the 5th day following operation than patients without complications, regardless of the presence of clinical signs of leaks.

Infrared thermal imaging: a potential tool used in open colorectal surgery.

Aim of this pilot study was to assess blood perfusion of bowel in resection lines by means of the infrared thermal imaging in order to choose the best place for anastomosis. The paper brings a first experience with infrared thermal imaging used in colorectal surgery operation from initial observation of the patient with T3 adenomatous carcinoma with no lymph node metastasis. The obtained infrared images show a clear boundary between parts of the intestine with blood perfusion and without it. The proposed position of resection of colon identified by infrared camera is in accordance with routinely designated position. Infrared thermal imaging seems to be a complimentary diagnostic method to see the perfusion in colorectal surgery.