The clinical relevance of KRAS gene mutation in non-small-cell lung cancer.

PURPOSE OF REVIEW: There are conflicting data on the potential prognostic and predictive role of mutant KRAS in non-small-cell lung cancer (NSCLC). RECENT FINDINGS: KRAS is the most frequently mutated oncogene in lung adenocarcinoma patients of non-Asian ethnicity. Novel data also revealed that allelic variants of mutant KRAS are different concerning their biochemistry, which may influence their prognostic and predictive role in NSCLC. Though mutant KRAS is not the target of molecular therapy yet, a molecular diagnostic algorithm involving KRAS determination can define a subgroup of tumors where no further diagnostic test is necessary due to the exclusivity of this driver oncogene mutation. Recent data indicated that the prognostic role of mutant KRAS in lung adenocarcinomas in Asian patients is evident, while more research is neccessary in non-Asian populations. Studies also suggest the potential predictive role of mutant KRAS in the context of chemosensitivity of NSCLC which may depend on the individual drug types. Recent data on the negative predictive role of KRAS mutation on the efficacy of EGFR tyrosine kinase inhibitor (TKI) therapies confirm previous findings. SUMMARY: Studies on the prognostic and predictive role of mutant KRAS in lung adenocarcinoma must be extended to the analysis of the potential role for allelic variants