coexistence of kras and braf mutations in colorectal cancer: a case report supporting the concept of tumoral heterogeneity

The detection of kras and braf 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 kras and braf mutations occur rarely in the colorectal cancers (crcs) with the prevalence of less than 0.001% of the cas es. in patients with kras-mutant tumors, braf mutations should not regularly be tested unless the patient is participating in a clinical trial enriching for the presence of kras or braf-mutated tumor. the current report demonstrates a case with advanced adenocarcinoma of the colon showing the coexistence of kras and braf mutations and may have profound clinical implications for disease progression and therapeutic responses.