KRAS mutant NSCLC, a new opportunity for the synthetic lethality therapeutic approach.

K-RAS accounts for 90% of RAS mutations in lung adenocarcinomas, the most commonly mutated oncogene in NSCLC, with mutations detected in about 25% of all tumors. Direct inhibition of KRAS has proven clinically challenging. So far, no successful targeted therapy has been developed and remains an elusive target for cancer therapy. Despite significant efforts, currently there are no drugs directly targeting mutated KRAS. Thus, new strategies have emerged for targeting RAS including the use of synthetic lethality. A specific knowledge of individual tumor molecular abnormalities that result in oncogene-specific "synthetic lethal" interactions will allow the rationale to combine promising targeted therapies for KRAS-mutated NSCLC. In this article, we review the new approach based on testing drugs or combinations of agents that work downstream of activated K-RAS.