This study describes a method to determine the likelihood of the development of metastasis in a subject suffering from cancer, in addition to a method to design a customized therapy in a subject suffering from cancer, in particular breast, colon, lung, kidney and thyroid cancer, based on the determination of the expression level of one or more genes whose expression is modulated by an increase in c-MAF expression. It also describes a method for the identification of marker genes with a propensity for metastatic cancer based on inducing the modulation of the c-MAF expression Finally, the use of PTHLH and PODXL inhibitors and RERG activators in the treatment and/or prevention of the cancer, in particular breast, colon, lung, kidney and thyroid cancer.