KRAS G12C Mutation is Less Common in Primary Lung Mucinous Adenocarcinoma

Summary: Primary lung mucinous adenocarcinoma (PLMAC) commonly harbors KRAS mutations. However, the frequency of different KRAS variants in PLMAC has rarely been reported. We aim to investigate the KRAS mutational profile in PLMAC. A total of 117 patients with PLMAC were identified. In the PLMAC cohort, 62 out of 86 patients had KRAS mutations. KRAS variants included G12V , G12D, G12C , and others . PLMAC had significantly fewer KRAS G12C mutations than PLNMAC (19% vs. 47%, p < 0.05) and KRAS G12C mutation was not detected in the never smokers, indicating that patients with PLMAC would be less likely to benefit from KRAS G12C targeted therapy. The value of using KRAS G12C to distinguish PLMAC from mucinous adenocarcinoma of other organ sites was limited, as only 1/5 of PLMAC cases had this variant.