Molecular Markers in the Pathogenesis of Cholangiocarcinoma: Potential for Early Detection and Selection of Appropriate Treatment

A review of the impact of obesity on common gastrointestinal malignancies

Obesity is a global pandemic and is a well-recognized risk factor for various gastrointestinal diseases. The prevalence of obesity is increasing across all age groups. There is an emergent need for focused guidelines aimed at reducing the incidence, prevalence, and associated risks of obesity. The impact of obesity on gastrointestinal cancers being multifactorial adversely influences the associated risk, disease course, prognosis, and overall survival. We have summarized the current literature highlighting the association between obesity and common gastrointestinal cancers, with specific focus on esophageal adenocarcinoma, colon cancer, hepatocellular cancer, cholangiocarcinoma, and pancreatic malignancies.

Expression of Molecular Differentiation Markers Does Not Correlate with Histological Differentiation Grade in Intrahepatic Cholangiocarcinoma

The differentiation status of tumor cells, defined by histomorphological criteria, is a prognostic factor for survival of patients affected with intrahepatic cholangiocarcinoma (ICC). To strengthen the value of morphological differentiation criteria, we wished to correlate histopathological differentiation grade with expression of molecular biliary differentiation markers and of microRNAs previously shown to be dysregulated in ICC. We analysed a series of tumors that were histologically classified as well, moderately or poorly differentiated, and investigated the expression of cytokeratin 7, 19 and 903 (CK7, CK19, CK903), SRY-related HMG box transcription factors 4 and 9 (SOX4, SOX9), osteopontin (OPN), Hepatocyte Nuclear Factor-1 beta (HNF1β), Yes-associated protein (YAP), Epithelial cell adhesion molecule (EPCAM), Mucin 1 (MUC1) and N-cadherin (NCAD) by qRT-PCR and immunostaining, and of miR-31, miR-135b, miR-132, miR-200c, miR-221 and miR-222. Unexpectedly, except for subcellular location of SOX9 and OPN, no correlation was found between the expression levels of these molecular markers and histopathological differentiation grade. Therefore, our data point toward necessary caution when investigating the evolution and prognosis of ICC on the basis of cell differentiation criteria.

Obesity and cholangiocarcinoma

It is estimated that about half of the population in developed countries are either overweight or obese. In some developing nations obesity rates have increased to surpass those seen in Western countries. This rate increase in obesity has many implications as obesity has been associated with numerous negative health effects including increased risks of hypertension, diabetes, cardiovascular disease, stroke, liver disease, apnea, and some cancer types. Obesity is now considered to be one of the major public health concerns facing the society. Cholangiocarcinomas (bile duct cancers) are malignant tumors arising from cholangiocytes inside or outside of the liver. Although cholangiocarcinomas are relatively rare, they are highly lethal. The low survival rate associated with cholangiocarcinoma is due to the advanced stage of the disease at the time of diagnosis. Prevention is therefore especially important in this cancer type. Some data suggest that the incidence of cholangiocarcinoma in the western world is on the rise. Increasing rate of obesity may be one of the factors responsible for this increase. Determining whether obesity is a risk factor for cholangiocarcinoma has significant clinical and societal implications as obesity is both prevalent and modifiable. This paper seeks to provide a summary of the current knowledge linking obesity and cholangiocarcinoma, and encourage further research on this topic.