Fast Five Quiz: KRAS Mutations in Non-Small Cell Lung Cancer

Winston W. Tan, MD; Maurie Markman, MD


August 16, 2022

Figure 2. KRAS molecular model.

According to the most recent guidelines from the National Comprehensive Cancer Network (NCCN), patients with a known activating KRAS mutation are unlikely to benefit from further molecular testing because the presence of overlapping targetable mutations is unlikely.

Guidelines from the American Society of Clinical Oncology note that KRAS molecular testing is not indicated as a routine stand-alone test as the sole determinant of targeted therapy. KRAS should be included as part of larger testing panels performed either initially or when routine EGFR, ALK, BRAF, and ROS1 test results are negative, per the same guidelines.

KRAS mutations may be seen in squamous cell carcinoma of the lung, although this is rare. Similarly, KRAS-mutated NSCLC is most common in people who smoke, but it has also been found in never-smokers. Thus, all patients with NSCLC should have their tumor tissue tested for mutations including BRAF, EGFR, KRAS, ALK, and ROS1.

Learn more about molecular testing in NSCLC.


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