Chemotherapy in the treatment of neuroendocrine malignant tumors

The efficacy of chemotherapy in digestive neuroendocrine tumors (NET) depen ds on primary site and histological differentiation. Many reports have sugg ested a superior activity of chemotherapy for pancreatic NET than for metas tatic carcinoid tumors with response rates ranging from 40 to 60% compared to 20%. The standard chemotherapy for pancreatic NET is a combination of ad riamycin and streptozocin and to a lesser extent a combination of 5FU and s treptozocin. In contrast, there is no clear standard chemotherapy for carci noid tumors and if most oncologists use a combination of 5FU and streptozoc in in the case of advanced, progressive and nonresectable carcinoid tumors, the results are mostly poor and the benefit seldom counterbalances its tox icity. In these carcinoid tumors the combination of hepatic artery ischemia alternating with chemotherapy has given impressive results in one study, w hich, however, have never been confirmed. Tumor cell differentiation is a m ajor prognostic factor and some reports have suggested a higher chemosensit ivity for undifferentiated or poorly differentiated NET with tumor response rates ranging from 41 to 69% when a VP16-CDDP combination is used. This ch emosensitivity is, unfortunately, as in small cell lung carcinomas, of shor t duration. Related to this special problem and the number of other active treatments in NET, the place of chemotherapy always has to be discussed in a multidisciplinary fashion. Surgical excision, chemoembolization, interfer ons and somatostatin analogues have to be emphasized and eventually combine d with chemotherapy, especially in slowly growing tumors. New active chemot herapy regimens have to be tested clearly in this orphan group of tumors wh ich does not hold much interest to the pharmaceutical companies. Copyright (C) 2000 S. Karger AG, Basel.