Chemotherapy for neuroendocrine tumors: the Beatson Oncology Centre experience

The role of chemotherapy in malignant neuroendocrine tumours is difficult to assess because of their rarity and variation in biological behaviour. We present a retrospective review of chemotherapy given to 18 patients with metastatic and one with locally advanced neuroendocrine tumours. There were eight poorly differentiated neuroendocrine tumours, six thyroid medullary carcinomas, two phaeochromocytomas, two pancreatic islet cell tumours and one undifferentiated neuroblastoma. Four patients were given 3-weekly dacarbazine, vincristine and cyclophosphamide (DOC) chemotherapy. In eight patients, this regimen was modified by substituting the dacarbazine and cisplatin and etoposide (OPEC). A further six patients were treated with dacarbazine reintroduced into the 3-weekly regimen (DOPEC). The remaining patient received cisplatin and etoposide. There were two complete responses (both with OPEC) and eight partial responses (two with DOC, three with OPEC and three with DOPEC). Five patients had stable disease and four progressed. Four received further chemotherapy on relapse, producing one complete and one partial response. The median response duration to initial chemotherapy was 10 months (range 3-34). The median survival was 12 months (range 1-42). The main toxicity was haematological, with grade 3-4 neutropenia in 12 patients; eight suffered episodes of sepsis. One death was treatment related. Other toxicity was mild although three patients discontinued vincristine with grade 2 neurotoxicity. The response rate and side effects of these three regimens appear comparable. We conclude that, although these patient numbers are small, combination chemotherapy produces an encouraging response rate (53%; 95% CI 30-75) in malignant neuroendocrine tumours, with acceptable toxicity.