Personalized treatments of cancer patients: a reality in daily practice, a costly dream or a shared vision of the future from the oncology community?

Therapies targeting activated oncogenes have been associated with several successes in the last decades that are described in this review, together with their limits and related unsolved questions. Most of the tumours will eventually develop drug resistance potentially due to intratumor heterogeneity and selection of additional molecular events. Moreover, studies in the field of molecular characterisation of cancers have shown that most tumors include large number of rare genomic events. Developing new drugs requires the use of large-scale molecular screening programs to enrich phase I/II trials with patients presenting the genetic alterations to treat them with the appropriate drug(s). Administering one single drug will incur in non-durable results, so the future is to cleverly combine drugs. Development of personalized immunotherapeutics and/or anti-angiogenic agents could change the natural history of several cancers. Finally, other systems including DNA repair and metabolism have become targetable. These considerations justify the development of molecular medicine with the characterisation of each tumour to assess defects in all the systems previously mentioned to propose a unique combination of therapies to each patient. Current drug development is clearly not appropriate, and studies with drugs given in relevant combinations should be favoured by new relationships between academia and industry. New organisational and medico-economics approaches are required to minimize the financial burden of personalized medicine by considering the foreseen decrease of the costs of new technologies, and the money saved by avoiding the use of many costly, useless but nonetheless toxic treatments given after failure of standard therapy.