KRAS and adenocarcinoma: The only two genes that had a net rate of mutation that was more than 5% higher in adenocarcinoma were KRAS and APC. KRAS is estimated to be mutated in 14% of adenocarcinomas, but only 1% of SCC, and APC is calculated to be mutated in 13% of adenocarcinomas and 5% of SCC.