Ways to perform an endoscopic tattoo. Prospective and randomized study in patients with colorectal neoplasm.

BACKGROUND AND AIMS: intraoperative identification of colonic lesions previously detected via colonoscopy may be difficult. Endoscopic tattooing facilitates identification, but there is no evidence regarding which is the best tattoo technique. The goal of the study was to describe the efficacy and safety of endoscopic tattooing and to detect technical and clinical factors associated with its efficacy. PATIENTS AND METHODS: a prospective and randomized study was performed. All tattoo candidate patients were included prior to surgery and randomized into four groups; tattoo at two or three injection points and with a volume of 1 or 1.5 ml of labeling. Multiple variables were registered. RESULTS: one hundred and ninety-five patients were included with an endoscopic tattoo and who subsequently underwent a surgical intervention, the mean age was 70.1 years and 67.2 % were male. The laparoscopic approach was applied in 57.9 % of cases. The intraoperative visibility of the endoscopic tattoo was 89.7 % and 30 % of rectal lesions were not visible. Excluding the rectum, the marking was visible intraoperatively in 92 % of patients, without significant differences according to the surgical approach, the type of marking or any of the variables collected. The tattoo was safe in 92.3 % of the cases. The adverse effect rate was 7.7 % and none of the complications were clinically significant. There were no significant differences between any variables collected in relation to adverse effects. CONCLUSIONS: endoscopic colon tattoo is safe and effective regardless of the technique used. We recommend the technique of two injection points and 1 ml of marking volume for its simplicity, efficiency and safety.

Telomere length alterations in microsatellite stable colorectal cancer and association with the immune response.

Telomeres are repetitive sequences (TTAGGG) located at the end of chromosomes. Telomeres progressively shorten with each cell replication cycle, ultimately leading to chromosomal instability and loss of cell viability. Telomere length anomaly appears to be one of the earliest and most prevalent genetic alterations in malignant transformation. Here we aim to estimate telomere length from whole-exome sequencing data in colon tumors and normal colonic mucosa, and to analyze the potential association of telomere length with clinical factors and gene expression in colon cancer. Reads containing at least five repetitions of the telomere sequence (TTAGGG) were extracted from the raw sequences of 42 adjacent normal-tumor paired samples. The number of reads from the tumor sample was normalized to build the Tumor Telomere Length Ratio (TTLR), considered an estimation of telomere length change in the tumor compared to the paired normal tissue. We evaluated the associations between TTLR and clinical factors, gene expression and copy number (CN) aberrations measured in the same tumor samples. Colon tumors showed significantly shorter telomeres than their paired normal samples. No significant association was observed between TTLR and gender, age, tumor location, prognosis, stromal infiltration or molecular subtypes. The functional gene set enrichment analysis showed pathways related to immune response significantly associated with TLLR. By extracting a relative measure of telomere length from whole-exome sequencing data, we have assessed that colon tumor cells predominantly shorten telomeres, and this alteration is associated with expression changes in genes related to immune response and inflammation in tumor cells.

Clinical guidelines for endoscopic mucosal resection of non-pedunculated colorectal lesions.

This document summarizes the contents of the Clinical Guidelines for the Endoscopic Mucosal Resection of Non-Pedunculated Colorectal Lesions that was developed by the working group of the Spanish Society of Digestive Endoscopy (GSEED of Endoscopic Resection). This document presents recommendations for the endoscopic management of superficial colorectal neoplastic lesions.

Clinical guidelines for endoscopic mucosal resection of non-pedunculated colorectal lesions. / Guía clínica para la resección mucosa endoscópica de lesiones colorrectales no pediculadas.

This document summarizes the contents of the Clinical Guidelines for the Endoscopic Mucosal Resection of Non-Pedunculated Colorectal Lesions that was developed by the working group of the Spanish Society of Digestive Endoscopy (GSEED of Endoscopic Resection). This document presents recommendations for the endoscopic management of superficial colorectal neoplastic lesions.