Predictive value of KRAS gene status on the effects of the first-line chemotherapy combined with bevacizumab treating metastatic colorectal cancer

ObjectiveTo investigate the predictive value of KRAS gene status on the effects of the first-line chemotherapy combined with bevacizumab treating metastatic colorectal cancer(mCRC).

MethodsKRAS gene in 216 patients with mCRC was detected, and the patients were treated with the first-line chemotherapy combined with bevacizumab for 4~8 cycles.After every 4 cycles of chemotherapy, the patients were detected using colonoscopy, abdominal B-ultrasound and enhanced CT.The relationships between the mutation status of the KRAS gene, and response rate(RR), pogression free survival(PFS), total survival(OS) in all patients were analyzed according to the evaluation criteria of solid tumor efficacy.

ResultsKRAS gene mutations were found in 34.2% of patients with mCRC.The number of patients with tumor transferring to the lung and liver in KRAS gene mutation group was more than that in KRAS gene wild-type group(P < 0.05 and P < 0.01).Compared to the KRAS gene wild-type group, the case of low differentiation type tumor in KRAS gene mutation group was more than that of the medium/high differentiation type tumor(P < 0.01).The differences of the RR and PFS between two groups were not statistically significant(P>0.05).The OS in KRAS gene mutation group decreased compared to the wild-type group, but the difference of which between two groups was not statistically significant(P>0.05).The neutropenia, gastrointestinal reaction, fatigue, proteinuria and other adverse reactions in two groups were similar.The Cox survival analysis model showed that the KRAS gene mutation was not set as a prognostic factor of PFS and OS(P>0.05).

ConclusionsThe mutation status of the KRAS gene does not play a prognostic role in mCRC patients treated with the first-line chemotherapy combined with bevacizumab.