Evaluation of RAS Mutational Status in Liquid Biopsy to Monitor Disease Progression in Metastatic Colorectal Cancer Patients.

In this study we evaluated both~ K- and N-RAS mutations in plasma samples from patients with metastatic colorectal cancer by means of the BEAMing technology, and we assessed their diagnostic performance compared to RAS analyses performed on tissue. The sensitivity of BEAMing in identifying KRAS mutations was of 89.5%, with a fair specificity. The agreement with tissue analysis was moderate. The sensitivity for NRAS was high with a good specificity, and the agreement between tissue analysis and BEAMing was fair. Interestingly, significantly higher mutant allele fraction (MAF) levels were detected in patients with G2 tumors, liver metastases, and in those who did not receive surgery. NRAS MAF level was significantly higher in patients with mucinous adenocarcinoma and for those with lung metastases. A sharp increase in the MAF values was observed in patients who moved towards disease progression. More strikingly, molecular progression always anticipated the radiological one in these patients. These observations pave the way to the possibility of using liquid biopsy to monitor patients during treatment, and to enable oncologists to anticipate interventions compared to radiological analyses. This will allow time to be saved and ensure a better management of metastatic patients in the near future.

Bevacizumab in non-small cell lung cancer.

Lung cancer continues to be the leading cause of cancer death in Western countries. The median survival time for advanced non-small cell lung cancer (NSCLC) remains poor and chemotherapy is the treatment of choice for most patients with metastatic NSCLC. Platinum-based chemotherapy has long been the standard of care for advanced NSCLC. The formation of new blood vessels (angiogenesis) is needed for the growth and invasiveness of primary tumours, and plays an important role in metastatic growth. Vascular endothelial growth factor (VEGF) has emerged as a key potential target for the pharmacological inhibition of tumour angiogenesis. This review discusses current data and the future potential of bevacizumab, a recombinant humanized monoclonal antibody that binds VEGF, in the treatment of NSCLC. Results from a phase II study showed that the addition of bevacizumab to the first-line chemotherapy with paclitaxel and carboplatin (CP) may increase the overall survival (OS) and the time to progression in advanced NSCLC. Based on these promising results, a randomized phase III trial compared the combination of bevacizumab with CP versus CP alone in the treatment of advanced non-squamous NSCLC. The combination of CP plus bevacizumab led to a statistically significant increase in median OS and progression-free survival (PFS) compared with CP alone, with a response rate (RR) in the CP arm of 15% compared with 35% in the bevacizumab plus CP arm (p < 0.001). More recently, the randomized AVAIL (Avastin in Lung Cancer) study, which evaluated cisplatin with gemcitabine plus bevacizumab in two different dosages versus chemotherapy alone in 1043 patients with recurrent or advanced non-squamous NSCLC, reported a significant increase of PFS, RR and duration of response for both of the bevacizumab-containing arms. Bevacizumab has also been investigated in combination with erlitonib as second-line treatment in two small early phase trials, with interesting results. Bevacizumab was generally well tolerated in clinical trials; the main treatment-associated adverse events were neutropenia and haemorrhage, especially in the lung, but also at other sites. Several trials that incorporate bevacizumab in combination with new active drugs in NSCLC are ongoing and should further help to define the place of bevacizumab in the therapy of NSCLC.