Despite vast investment for decades in cancer research and development, cancer is still among the leading causes of death worldwide and its toll is expected to rise by about 70% over the next two decades. There are many aspects of cancer, including its complexity, diversity, and dynamic nature, which call for a radical change in the way we approach cancer study and management. For instance, the genetic profile of tumors affects patient tumor response while the tumor microenvironment plays a critical role in cancer development, progression, and control. Due to intra-tumoral heterogeneity, cancer cells extracted from the same tumor of a patient may be genetically heterogeneous. Tumor/host immune interactions influences disease outcome by altering the balance of suppressive versus cytotoxic responses in the vicinity of the tumor. In addition, biopsies often suffer from sample bias, and tumor sampling from some cancer types still remains difficult resulting in insufficient amount of tissue for genetic testing. Considering the high tumor heterogeneity from individual patients, it is increasingly recognized that a personalized medicine approach would help identifying the optimal treatment regimen for an individual patient, calibrated on his/her specific cancer signature, reducing toxicity from overtreatment and increasing efficacy of therapy.

However, in order to pursue personalized approaches, novel approaches capable of improving the care of cancer patients through earlier detection, better therapy monitoring, new drug development and rational treatment planning are urgently needed.

One of the challenges of personalized medicine is related to the so-called liquid biopsy, that is the extraction of circulating tumor cells (CTC) and cell-free or circulating tumor DNA (ctDNA) from peripheral blood, which is expected to revolutionize the way in which cancer care works nowadays, by providing easy and repeatable access to tumor biological material, and consequently to the information about disease state, prognosis and chemo-sensitivity contained in it. On the other hand, also because of the epithelial-to-mesenchymal transition, not much is known at present about how the peripheral blood samples the tumor material, adding urgency to the type of study discussed above. Another challenge of personalized medicine is represented by the assembly of suitable in vitro tumor models capable of predicting the response to specific chemotherapeutic agents for each patient. I will present to you today a new method to recognize, count, sort and analyze CTCs.