Tumor biology as a basis for molecular targeting in cancer

Revolutionary discoveries in cancer genomics in the last 10 years and the development of rapid genomic sequencing have led to a sea change in our understanding of the genetic events contributing to malignant transformation of cells and maintenance of the malignant state. This new understanding of the cancer genome allows implementation of specific therapies to suppress tumor growth. This review summarizes current knowledge of tumor biology as a basis for molecular targeting of cancer for imaging and/or therapy purposes. Important molecular events related to tumor biology are presented, focusing, in particular, on the knowledge that can contribute to the development of molecular targeting processes related to important aspects of cancer growth/metastasis. We discuss the relevance of these events to tumor mass imaging, tumor neovasculature development, tumor hypoxia, cellular constituents and cell-cell synergism of the tumor mass, the immunologic sanctuary of tumors, the metastatic process, oncogene and non-oncogene addiction, driver mutations in cancer cells, the PI3K/AKT and RAS/ERK pathways, B-RAF inhibition, and carbonic anhydrase 9 in clear cell renal cancer. All this knowledge, which can be encompassed by the general term metabolomics, can translate into practical applications for imaging the cancer cell phenotype. There is no doubt that this kind of precision medicine will increase the capacity of molecular imaging to monitor tumor-specific targeted treatments and determine the point in time when the cancer mutates again and escapes drug control.