Colonic polyps: Is it useful to characterize them with advanced endoscopy?

There have been major developments in endoscopic imaging techniques in recent years.Endoscopes with high definition and magnification can provide high quality images that allow for the histological estimation of lesions in vivo and in situ when combined with ancillary enhancement techniques such as chromoendoscopy(CE)and virtual CE(narrow band imaging fujinon intelligent chromoendoscopy,or i-Scan).Despite the enormous potential for these advanced techniques,their value and feasibility in the clinic are still doubted,particularly in cases of colonic polyps that are slated for removal,where in vivo characterization may be deemed unnecessary.However,there are several advantages offered by such advanced endoscopic imaging.CE with or without magnification demonstrates highly accurate histology and invasion depth prediction,and virtual CE is a feasible and less cumbersome alternative to CE in terms of histological estimation,though not sufficiently accurate for depth invasion prediction.Furthermore,the supplementary information provided by advanced imaging systems can assist the endoscopist in the selection of a strategic approach,such as in deciding whether a colonic lesion should be resected,left in situ,or requires more intensive surgical treatment.Lastly,advanced high-resolution imaging techniques may be more cost effective,such that histopathology of lowrisk lesions following resection can be eliminated.The results of these evaluations and comparisons with traditional CE are presented and discussed.Taken together,the benefits provided by these advanced capabilities justify their development,and advocates their use for the treatment and management of colonic polyps.

Rare germline copy number variants in colorectal cancer predisposition characterized by exome sequencing analysis

Colorectal cancer （CRC） is one of the most common neoplasms and an important cause of mortality worldwide （http：//globocan. iarc.fr]）. Approximately 35% of the variation in CRC susceptibility is likely due to heritable factors （Lichtenstein et al., 2000}. Genetic variations in the human genome include single nucleotide variants （SNVs）, short insertions and deletions, and larger structural variants resulting in gain or loss of genomic DNA larger than 1 kb, such as copy number variants （CNVs）. Leaving aside the importance of CNVs in sporadic tumor development, these variants can also be present in the germline DNA of healthy individuals from the general population and be considered polymorphic.