Herbert Loong, an advisor at the Greater Bay Area International Clinical Trial Institute, has highlighted the evolving landscape of KRAS G12C mutations in Asia, focusing on their implications for cancer treatment. In a recent LinkedIn post, he revisited findings from a 2020 study that examined the prevalence of KRAS mutations in tumor samples from multiple centers across China.
The study analyzed 11,951 tumor samples and found that KRAS mutations were present in 16.6% of cases, with G12C mutations comprising 14.5% of these, or 2.4% of the total samples. Notably, the G12C mutation was most prevalent in lung cancer (4.3%), colorectal cancer (2.5%), and biliary tract cancer (2.3%). Within the category of lung cancer, G12C mutations represented the largest subgroup at 35.9%.
Loong’s team noted significant variances between mutation rates in Asian patients compared to data from Western populations. Specifically, lower rates of KRAS mutations were observed in lung cancer, while higher rates were recorded in pancreatic, colorectal, and gastric cancers. Additionally, in lung adenocarcinoma, KRAS mutations appeared more frequently in former and current smokers than in never-smokers.
Among the G12C tumors analyzed, 99.5% exhibited co-alterations, with an average of 14 modifications. The most common co-alteration was TP53, while STK11 was found in 18% of lung adenocarcinoma cases, and PIK3CA mutations were more common in colorectal cancer than in lung adenocarcinoma. These findings may help explain the differing responses to early G12C inhibitors between lung and colorectal cancers, Loong suggested.
As the field progresses towards 2026, significant developments have occurred. Several KRAS G12C inhibitors have been approved, including new treatments developed in China, increasing patient access. Treatment strategies in colorectal cancer are evolving from monotherapy to combinations with anti-EGFR therapies, reflecting the biological differences across tumor types. Current clinical trials are also exploring first-line combinations and next-generation RAS inhibitors, prompting new questions regarding patient selection.
Co-mutations like STK11 and KEAP1 are becoming increasingly vital in interpreting treatment outcomes for patients with KRAS-mutant lung cancers. Loong emphasized the importance of population-specific data in optimizing the feasibility of clinical trials in Asia, including testing yields and identifying patients who may exhibit primary resistance to therapies.
The insights derived from large real-world data sets are valuable, though they do not replace the necessity for prospective clinical trials, according to Loong. He expressed gratitude to his co-authors, including Tony Mok and Lunxu Liu, and to the contributing centers and OrigiMed.
The findings and further context on KRAS G12C mutations are detailed in the study titled, KRAS G12C mutations in Asia: a landscape analysis of 11,951 Chinese tumor samples, authored by Loong and colleagues.
