Prognostic role of KRAS in the treatment of colorectal liver metastases

Mutations at KRAS gene have been identified as effective predictive biomarker against treatment of colorectal liver metastases (CLM) with anti EGFR monoclonal antibodies. On the other hand its value as considerable prognostic biomarker is still unclear. Thus we examined this issue in a cohort of patients with colorectal liver metastases.KRAS mutation status was assessed in sixty-two resected liver metastases and in forty corresponding primitive colorectal cancers. Genotypes of KRAS were analysed by cycleave PCR. We examined the association of KRAS mutation with clinic-pathological features, recurrence rate and survival. Median follow-up after liver resection was 42.9 months. KRAS mutations in CLM were detected in 18 patients (29%); the most frequent mutation was G12D (34%). A high concordance of mutations has been demonstrated between the primary and LM (90%, p=0.0001). No significant marker correlation has been revealed with clinic-pathological features. Biomarker mutations were slightly associated with extra-hepatic metastases either discovered at the time of diagnosis (p=0.07) or during the follow-up (p=0.09). The 5-years survival was not influenced by the presence of mutations in KRAS (55% Vs 59%). At regard to these little differences, is important to stress that 55% of KRAS mutated patients underwent anti-VEGF target therapy KRAS is not significantly associated with an aggressive metastatic behaviour of colorectal liver metastases. These results are consistent with the majority of data in literature suggesting in the target therapy era offering multiple effective weapons even in KRAS mutated, it s really hard to determine plain prognostic value of KRAS