Many single institutional studies have tried to define some prognostic tools for selecting patients who could benefit from CT2, such as age, performance status, surgery for primary tumour, a good response to first-line therapy, PFS longer than 6 months, neutrophil-to-lymphocyte ratio, and carcinoembryonic antigen, CA19-9, leucocyte, cholinesterase and albumin concentrations [32]. This evidence concerns the gene BCHE and neoplasm.