Ravi Murthy

BACKGROUND: The objective of this study was to determine the prognostic variables that influence response and survival in patients with metastatic neuroendocrine tumors who are treated with hepatic arterial embolization (HAE) or chemoembolization (HACE). METHODS: Patients with metastatic neuroendocrine tumors who underwent HAE or HACE were included in this retrospective study. Follow-up imaging studies were compared with baseline imaging to determine the radiologic response. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to assess the prognostic variables that affected response and survival. RESULTS: The study included 69 patients with carcinoid tumors and 54 patients with pancreatic islet cell carcinomas. Patients who had carcinoid tumors had a higher response rate (66.7% vs. 35.2%; P = 0.0001) and had longer PFS (22.7 mos vs. 16.1 mos; P = 0.046) and OS (33.8 mos vs. 23.2 mos; P = 0.012) compared with patients who had islet cell carcinomas. For patients with carcinoid tumors, multivariate analysis identified male gender as the only independent risk factor for poor survival (P = 0.05). Octreotide was predictive marginally for PFS (P = 0.06). Patients who were treated with HAE had a higher response rate than patients who were treated with HACE (P = 0.004). For patients with islet cell carcinoma, an intact primary tumor, > or = 75% liver involvement, and extrahepatic metastases were associated with reduced OS in the univariate analysis; the presence of bone metastases was the only risk factor (P = 0.031) in the multivariate analysis. Patients who were treated with HACE had a prolonged OS (31.5 mos vs. 18.2 mos) and improved response (50% vs. 25%) compared with patients who were treated with HAE, although the differences did not reach statistical significance. CONCLUSIONS: Patients with carcinoid tumors had better outcomes than patients with islet cell carcinomas. The addition of intraarterial chemotherapy to HAE did not improve the outcome of patients with carcinoid tumors, but it seemed to benefit patients with islet cell carcinomas. In patients who had carcinoid tumors, male gender predicted a poor outcome, and a trend toward prolonged PFS was observed in patients who received concomitant octreotide. An intact primary tumor, extensive liver disease, and bone metastases were associated with reduced survival in patients with islet cell carcinomas.

PURPOSE: The use of 90Y-microspheres to treat unresectable liver metastases originating from a variety of neuroendocrine tumors was reviewed. MATERIALS AND METHODS: This is a retrospective review from 10 institutions of patients given 90Y-microsphere therapy for neuroendocrine hepatic metastases. Physical, radiographic, biochemical, and clinical factors associated with treatment and response were examined. All patients were followed with laboratory and imaging studies at regular intervals until death, or censured whether other therapy was given after brachytherapy. Toxicities (acute and late) were recorded, and survival of the group determined. RESULTS: A total of 148 patients were treated with 185 separate procedures. The median age was 58 years (26-95 years) at treatment with median performance status of Eastern Cooperative Oncology Group (0). The median activity delivered was 1.14 GBq (0.33-3.30 GBq) with a median of 99% of the planned activity able to be given (38.1%-147.4%). There were no acute or delayed toxicity of Common Terminology Criteria for Adverse Events v3.0 grade 3 in 67% of patients, with fatigue (6.5%) the most common side effect. Imaging response was stable in 22.7%, partial response in 60.5%, complete in 2.7% and progressive disease in 4.9%. No radiation liver failure occurred. The median survival is 70 months. CONCLUSION: Radioembolization with 90Y-microspheres to the whole liver, or lobe with single or multiple fractions are safe and produce high response rates, even with extensive tumor replacement of normal liver and/or heavy pretreatment. The acute and delayed toxicity was very low without a treatment related grade 4 acute event or radiation induced liver disease in this modest-sized cohort. The significant objective response suggests that further investigation of this approach is warranted.

Species of Clostridium bacteria are notable for their ability to lyse tumor cells growing in hypoxic environments. We show that an attenuated strain of Clostridium novyi (C. novyi-NT) induces a microscopically precise, tumor-localized response in a rat orthotopic brain tumor model after intratumoral injection. It is well known, however, that experimental models often do not reliably predict the responses of human patients to therapeutic agents. We therefore used naturally occurring canine tumors as a translational bridge to human trials. Canine tumors are more like those of humans because they occur in animals with heterogeneous genetic backgrounds, are of host origin, and are due to spontaneous rather than engineered mutations. We found that intratumoral injection of C. novyi-NT spores was well tolerated in companion dogs bearing spontaneous solid tumors, with the most common toxicities being the expected symptoms associated with bacterial infections. Objective responses were observed in 6 of 16 dogs (37.5%), with three complete and three partial responses. On the basis of these encouraging results, we treated a human patient who had an advanced leiomyosarcoma with an intratumoral injection of C. novyi-NT spores. This treatment reduced the tumor within and surrounding the bone. Together, these results show that C. novyi-NT can precisely eradicate neoplastic tissues and suggest that further clinical trials of this agent in selected patients are warranted.