Molecular Variances Between Right- and Left-sided Colon Cancers

AbstractPurpose of ReviewDuring the past few years, several important clinical and molecular differences have been observed simply based on anatomic tumor location of colorectal cancer. With this review, we aimed to give an updated overview of the recent findings on tumor location as a surrogate of embryological, molecular, and clinical differences that have a direct impact on our daily clinical practice.Recent FindingsIncreasing evidence has demonstrated a role for the microbiota in shaping inflammatory environments and promoting CRC growth and spread, and now we know that bacterial phylotypes vary depending on the primary tumor location. Compelling evidence has shown that tumor sidedness has both a strong prognostic and predictive value. In fact, right-sided colon cancers display a markedly worse prognosis compared to left-sided tumors; moreover, it seems that right-sided RAS wild-type metastatic colorectal cancer benefits from bevacizumab-based therapy while left-sided tumors have better outcomes with cetuximab-based treatment in the first-line setting. Since the underlying reasons of these differences are yet unknown, further investigations are warranted in this expanding and relevant field.SummaryIn this review, we summarize the actual knowledge on the clinical, microbiome, and molecular differences observed between right- and left-sided colon cancers. We also present an overview of the existing data on the prognostic and predictive impact of tumor sidedness on metastati...
Source: Current Colorectal Cancer Reports - Category: Cancer & Oncology Source Type: research