Identifying KRAS G12C NSCLC and Ordering Testing

Rajwanth R. Veluswamy, MD, MSCR, of the Perlmutter Cancer Center at NYU Langone Health, and Chinmay Jani, MD, of the University of Miami Sylvester Comprehensive Cancer Center, discuss identifying KRAS G12C-mutated non-small cell lung cancer (NSCLC) and ordering testing in practice. Dr. Veluswamy explains that KRAS G12C arises from a smoking-associated transversion, occurs almost always in adenocarcinoma histology, and shows no consistent pattern by age or sex, so he tests every patient with lung adenocarcinoma. Dr. Jani sends tissue and liquid biopsy together at diagnosis per current guidelines, noting the platforms work complementarily and can each catch alterations the other misses, and he adds RNA-based testing to capture fusion events. Both faculty agree that when results are delayed, the right approach is to start first-line chemotherapy and add targeted or immune therapy once testing returns, rather than waiting indefinitely before treating the patient.