Coexistence of and Mutations in Colorectal Cancer: A Case Report Supporting The Concept of Tumoral Heterogeneity.

The detection of and mutations is a crucial step for the correct therapeutic approach and predicting the epidermal growth factor receptor (EGFR)-targeted therapy resistance of colorectal carcinomas. The concomitant and mutations occur rarely in the colorectal cancers (CRCs) with the prevalence of less than 0.001% of the cases. In patients with -mutant tumors, mutations should not regularly be tested unless the patient is participating in a clinical trial enriching for the presence of or -mutated tumor. The current report demonstrates a case with advanced adenocarcinoma of the colon showing the coexistence of and mutations and may have profound clinical implications for disease progression and therapeutic responses.