New clinical trials for the treatment of neuroendocrine tumors.

In oncology there is an increasing interest in neuroendocrine tumors, whose incidence is generally considered low, although in a recent analysis of 5,468 cases there was an increase in the proportion of pulmonary and gastric carcinoids and a decrease in the appendiceal carcinoids. However carcinoid tumors are indolent and their diagnosis is often difficult to carry out, so the true incidence may be higher. Surgery remains the treatment of choice and it should always be considered in patients with neuroendocrine tumors although a complete cure is difficult to obtain. Cytotoxic chemotherapy is the medical treatment for highly proliferating neuroendocrine tumors, but it has showed a modest benefit. Somatostatin analogues, octreotide and lanreotide are the standard hormonal treatment for neuroendocrine tumors. Recently, two trials on lanreotide and octreotide have been published, and it is worth noting that in each trial a long-acting formulation has been used: for lanreotide a prolonged-release formulation (PR) which allows an injection of 30 mg every 2 weeks, and for octreotide a long-acting release formulation (LAR) which allows an injection of 10, 20 or 30 mg every 28 days. The results of each trial are very promising. However, there are methodological and clinical aspects which make it difficult to carry out new trials for studying neuroendocrine tumors. The increasing number of biological markers deserve further investigations before their wide use in clinical practice.