Uncovering Pandora's vase: the growing problem of new toxicities from novel anticancer agents. The case of sorafenib and sunitinib.

As newer, molecularly targeted, anticancer drugs are entering clinical practice, a wide array of previously unrecognised and ill defined side effects of these drugs are increasingly observed. Sorafenib and sunitinib are two of these novel agents, acting on tumour angiogenesis as well as on other key proliferative pathways; recently approved for the treatment of advanced kidney cancer, they may cause peculiar cutaneous, vascular and mucosal toxicities, including hand-foot skin reaction, skin rash, hypertension and GERD-like oesophagitis/gastritis. In this review, we shall deal with these poorly recognised, but sometimes extremely distressing, toxicities; pathophysiologic mechanisms will be discussed and suggestions for treatment of each toxicity will be proposed, based on the few pieces of evidence available and, especially, on our empirical experience.