Complete resection has been the only potentially curative treatment of patients with neuroendocrine tumors (NETs). Forunresectable NET, however, clinical benefit can be obtained through the molecular-targeted agent everolimus and several cytotoxic agents such as dacarbazine (DTIC), doxorubicin, and 5-fluorouracil. In a phase II trial of DTIC for advanced pancreatic NET, DTIC at 850 mg/m2 i.v. on day 1, repeated every 4 weeks, achieved a response rate of 33% (14/42), but was several severe toxicities, including sepsis. Here, we evaluated the efficacy and safety of DTIC in Japanese patients with unresectable NET.Patients and methods
We retrospectively analyzed consecutive NET patients who received chemotherapy with DTIC at 200 mg/m2 i.v. on days 1–5 or 250 mg/m2 on days 1–4, repeated every 4 weeks at our institution between October 2007 and January 2012.Results
Five men and one woman with a median age of 59.5 years (range, 38–66) were treated with DTIC. All cases were pathologically classified as NET G2 (WHO2010). Primary sites of tumors were the pancreas in five patients and thymus in one. Three patients were administered octoreotide concurrently, and one patient had previous chemotherapy with etoposide and cisplatin. Median number of treatment cycles was 5.5 (range, 5–24). One complete response and one partial response were achieved, resulting in an overall response rate of 33% (2/6). Another patient had long-term stable disease for nearly 2 years. Median time to treatment failure was 300 days (range, 133–718). Compared with the previous phase II trial, toxicity was mild, and no serious adverse events were observed.Conclusion
Treatment with DTIC was safe and feasible, and may be an option for Japanese patients with unresectable NET G2.