Emerging therapies and latest development in the treatment of unresectable pancreatic neuroendocrine tumors: an update for clinicians.

Pancreatic neuroendocrine tumors (pNETs) differ in their clinical behavior, presentation and prognosis based on their initial histological features and disease stage. While small resectable tumors can be treated surgically, metastatic and locally advanced disease carries a significant mortality and treatment options have been limited in terms of their efficacy. Streptozocin-based regimens were the only agents available before but recent advances have improved the armamentarium to treat pNETs. Newer chemotherapeutic agents such as temozolomide, somatostatin analogs and targeted therapies including everolimus and sunitinib are now available to treat these tumors. Several combination regimens with targeted therapies and newer agents such as pazopanib are being developed and tested in ongoing trials.

Biomarkers in neuroendocrine tumors.

Neuroendocrine tumors are a heterogeneous group of tumors with cells of neuroendocrine differentiation that arise from diverse anatomic sites with varying morphologic and clinical features. Since the natural history and prognosis varies widely between individual neuroendocrine tumor types, there is a critical need to identify accurate prognostic and predictive biomarkers and markers predictive of therapeutic efficacy. To date, plasma chromogranin-A levels have generally been accepted as the most useful biomarker, despite the fact that there are substantial concerns in sensitivity and discrepancies in measurement techniques. As a consequence, considerable attention has been focused upon the development of novel biomarkers that can be utilized with more clinical efficacy than chromogranin-A. In addition to amplifying the diagnostic/prognostic landscape, the need to calibrate the efficacy of biological targeted therapy has further accelerated the development of molecular biomarkers. At the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting, Chou et al. (Abstract #e15151) presented data that chromogranin A levels can be monitored during treatment to predict clinical outcome. Modlin et al. (Abstract #4137), demonstrated a promising novel biomarker, serum multi-transcript molecular signature. Grande et al. (Abstract #4140), Heetfield et al. (Abstract #e15071) and Casanovas et al. (Abstract #4139) described sVEGFR2, p-mTOR and IGF1R as molecular markers with potential for use in targeted therapy trials. The authors review and summarize these abstracts in this article.

Treatment of poorly differentiated neuroendocrine carcinoma of the pancreas.

Poorly differentiated neuroendocrine carcinoma is a rare malignancy that remains a challenge to treat. Poorly differentiated neuroendocrine carcinoma occurs at an incidence of 2% annually in United States. The current standard of care is based largely upon retrospective data. There remains a need for large prospective cooperative group trials in the management of poorly differentiated neuroendocrine carcinoma. In this paper, we will review abstract #e15096 (Paclitaxel, carboplatin, and etoposide (TCE) in advanced poorly differentiated neuroendocrine carcinoma) by Loeffler et al. and #e15071 (Poorly differentiated neuroendocrine carcinoma (NEC G3): prognostic factors and potential novel targets) by Heetfeld et al. presented at the 2013 ASCO Annual Meeting highlighting treatment options in first and second lines for poorly differentiated neuroendocrine carcinoma.

Autologous stem cell transplant recipients tolerate haploidentical related-donor natural killer cell-enriched infusions.

BACKGROUND: In the setting of allogeneic stem cell transplantation (SCT), infusing natural killer (NK) cells from a major histocompatibility complex (MHC)-mismatched donor can mediate an antileukemic effect. The graft-versus-tumor effect after autologous stem cell transplantation (ASCT) may result in less disease relapse. STUDY DESIGN AND METHODS: We performed a Phase I clinical trial to assess the safety and feasibility of infusing distantly processed donor NK-enriched mononuclear cell (NK-MNC) infusions from a MHC haplotype-mismatched (haploidentical) donor to patients who recently underwent ASCT for a hematologic malignancy. On Day 1, peripheral blood MNCs were obtained by steady-state leukapheresis and sent from Boston to the Production Assistance for Cellular Therapies (PACT) facility at the University of Minnesota, where immunomagnetic depletion of CD3 cells was performed on Day 2. NK-MNC products were then returned to Boston on Day 2 for infusion on Day 3. Toxicity, cellular product characteristics, and logistic events were monitored. RESULTS: At a median of 90 days (range, 49-191 days) after ASCT, 13 patients were treated with escalating doses of NK-MNCs per kilogram from 10(5) to 2 × 10(7) . Adverse effects included Grade 2 rigors and muscle aches, but no Grade 3 or 4 events and no graft-versus-host disease or marrow suppression. One air courier delay occurred. NK-MNC products were viable with cytotoxic activity after transport. CONCLUSION: CD3-depleted, MHC-mismatched allogeneic NK-MNC infusions can be safely and feasibly administered to patients after ASCT after distant processing and transport, justifying further development of this approach.