Prognostic and predictive biomarkers in metastatic colorectal cancer anti-EGFR therapy

AIM: To reviewing genetic and epigenetic make-up of metastatic colorectal cancers(m CRCs) addicted to epidermal growth factor receptor(EGFR) signalling.METHODS: The present study summarizes the potential value of prognostic and predictive biomarkers in selecting m CRC patients treated with anti-EGFR therapy. A meta-analysis was performed using a systematic search of Pub Med, Medline and Web of Science to identify eligible papers until March 21 st, 2016 using these following terms: ‘‘colorectal cancer'', "predictive biomarkers' ', "anti-EGFR therapy", "KRAS", "NRAS'', "PIK3CA", "TP53", "PTEN", ‘‘EGFR", "MET", "HER2", "epiregulin", "amphiregulin", "prognostic biomarkers", "BRAF", "miR NA" and "antibody-dependent cell-mediated cytotoxicity(ADCC) activity". Two investigators independently evaluated and extracted data from each identified studies based on selected criteria of inclusion and exclusion. RESULTS: The introduction of agents targeting EGFR such as cetuximab and panitumumab increased overall survival of mC RCs. Nevertheless, it has firstly became evident that response rates to cetuximab regimens in unselected patient populations were typically lower than 30%. Clinical data confirmed the predictive value of RAS mutations for resistance to cetuximab and panitumumab leading to the license of these monoclonal antibodies exclusively for the management of patients with RAS-wild type colorectal cancers. So far the identification of predictive biomarkers have generated interesting, though preliminary and, at times, conflicting data on the importance of tumour mR NA levels of EGFR ligands, of activating mutations in other genes such as NRAS and PIK3 CA. The prognostic value of selected micro RNAs level and ADCC activity is under investigation, while the prognostic impact of BRAF status remains controversial.CONCLUSION: This review focuses on the personalized treatment of m CRC and discusses the potential of new prognostic and predictive biomarkers in selecting patients treated with anti-EGFR therapy.

Circulating cytokines and outcome in metastatic colorectal cancer patients treated with regorafenib

BACKGROUND Regorafenib is an oral small-molecule multikinase inhibitor approved in third or later line of treatment for patients with metastatic colorectal cancer(mCRC).Regorafenib has shown significant benefits in overall survival and progression free survival in two phase III trials compared to placebo in patients with mCRC who had progressed on previous therapy.AIM To identify an immune profile that might specifically correlate with the outcome in patients treated with regorafenib.METHODS Blood samples were collected from 17 patients before treatment with regorafenib and from 6 healthy volunteers.The proteins evaluated(TNF-α,TGF-β,VEGF,CCL-2,CCL-4,and CCL-5)were selected on the basis of their roles in angiogenesis and colorectal cancer pathogenesis.RESULTS We found that TNF-αbasal level was significantly higher in mCRC patients compared to healthy individuals.Non Responder(NR)patients showing progression of disease(n=12)had higher basal level of TGF-β,TNF-α,VEGF,CCL-2 and CCL-5 compared to Responder(R)patients(complete response CR,n=1;partial response PR,n=1;Stable Disease SD,n=3).On the contrary,plasma basal level of CCL-4 was higher in R compared to NR patients.High values of TGF-βand TNF-αnegatively correlated with progression free survival.CONCLUSION These results suggest a cytokine signature potentially able to discriminate between R and NR patients to treatment with regorafenib.