The instant invention provides for a new method of treating colorectal cancer (CRC) and metastases thereof in subjects, and preferably also of other solid cancers and metastases thereof in subjects, wherein said method preferably depends on whether the patient shows certain specific proteins levels in one or more body fluids prior to or during treatment, wherein said treatment comprises the administration of at least one pan αv integrin inhibitor to a patient, a medicament for use in said new methods, and a method of predicting the outcome of a treatment with at least one pan αv integrin inhibitor based on said specific protein levels in one or more body fluids of the patient.