The treatment of undifferentiated neuroendocrine tumors.

The aggressiveness of poorly-differentiated neuroendocrine tumors is similar to small-cell lung cancer within a median survival of 6 months without treatment. Most patients have metastatic disease and poor condition at the time of diagnosis, and cannot be approached surgically with curative intent. Moertel et al. [Treatment of neuroendocrine carcinomas with combined etoposide and cisplatin, Cancer 1991;68:227--232] reported an objective response rate of 67% with a chemotherapy regimen combining etoposide plus cisplatin, with a median survival of 19 months and a median time to progression of 11 months. Since this publication, this regimen has been considered as the reference treatment for poorly-differentiated neuroendocrine tumors. A French retrospective study has recently confirmed the high chemosensitivity of those tumors. However, the prognosis remains poor with a 2-year survival lower than 20% and other therapeutic approaches should be developed.