Background: In this study, we aimed to investigate the frequency, prognostic effect of codon, and amino acid-specific KRAS mutations in patients with metastatic colorectal cancer (mCRC) and their predictive effect on irinotecan and oxaliplatin during first-line treatment.

Methods: The data of 304 mCRC patients were retrospectively evaluated between 2010 and 2018. Patients were categorized according to the most prominent codon and amino acid mutation and their prognostic features were analyzed.

Results: In total, 274 patients were included in the study and 128 patients (47%) revealed KRAS mutation. Median follow-up time was 19.8 months (range; 1.6–96). The median overall survival rates for patients with codons 12 and 13 mutations were 25.4 and 22.2 months, respectively (p = 0.4). Moreover, the median overall survival for the codon 12 mutant patients who received irinotecan-based chemotherapy in the first-line treatment was 42.7 months, whereas for the codon 13 mutant and KRAS wild-type patients, it was 18.3 and 23.9 months, respectively (codon 12 vs. codon 13; HR: 0.31, p = 0.03, codon 12 vs. wild-type; HR: 0.45, p = 0.03).

Conclusion: The significant survival advantage was observed in patients with codon 12 mutations who received irinotecan-based chemotherapy as a first-line treatment.

背景：在这项研究中，我们旨在调查转移性结直肠癌（mCRC）患者的密码子和氨基酸特异性KRAS突变的频率，预后效果以及在一线治疗期间对伊立替康和奥沙利铂的预测作用。

方法：对2010年至2018年间304例mCRC患者的资料进行回顾性评估，根据最突出的密码子和氨基酸突变对患者进行分类，并分析其预后。

结果：总共274例患者被纳入研究，其中128例患者（47％）表现出KRAS突变。中位随访时间为19.8个月（范围：1.6-96）。密码子12和13突变的患者的中位总生存率分别为25.4和22.2个月（p = 0.4）。此外，在一线治疗中接受伊立替康化学疗法的12位密码子突变患者的中位总生存期为42.7个月，而13位密码子突变体和KRAS野生型患者的中位总生存期分别为18.3和23.9个月（密码子12与密码子13； HR：0.31，p = 0.03，密码子12与野生型； HR：0.45，p = 0.03）。

结论：在接受基于伊立替康的一线治疗的密码子12突变患者中观察到了显着的生存优势。