Abstract
Treatment personalisation plays a key role in the current management of patients with cancer. Several biomarkers have shown clinical utility and may guide therapeutic decisions. Amongst patients with lung cancer, the level of expression of programmed death ligand 1 (PD-L1) has both prognostic and predictive values in terms of response to the inhibition of programmed cell death protein 1 (PD-1). Depending on the clinical setting, the expression of PD-L1 ≥1% or ≥50% has been associated with improved outcomes amongst patients receiving pembrolizumab. Regarding patients with colorectal carcinoma, mutations in the KRAS oncogene predict the responsiveness to the inhibition of epidermal growth factor receptor (EGFR). Only patients with wild-type KRAS tumours derive benefit from cetuximab and panitumumab in terms of response and survival. In conclusion, future research should aim in the optimisation of the use of biomarker in the clinical practice in order to provide the optimal drug combination to each individual patient.