Nitya Prabhakar Raj

Treatment Response and Outcomes of Grade 3 Pancreatic Neuroendocrine Neoplasms Based on Morphology: Well Differentiated Versus Poorly Differentiated.

Objectives Emerging data suggest that not all grade 3 (G3) pancreatic neuroendocrine neoplasms (panNENs) behave the same; tumor differentiation may predict outcome. Methods Patients with G3 panNENs treated at our institution between 1999 and 2014 were identified. Demographics, response to therapy, and overall survival were determined. Results Forty-five patients were identified, 16 with G3 well differentiated pancreatic neuroendocrine tumors (WD-panNETs) and 29 with poorly differentiated neuroendocrine carcinomas (PDNEC). Median overall survival in G3 WD-panNET patients was 52.2 months (95% confidence interval, 19.3–86.9 months) compared with 10.1 months (95% confidence interval, 6.9–12.4 months) in PDNEC patients (P = 0.0009). Response rate to platinum agents was 10% in G3 WD-panNETs and 37% in PDNEC. Response rate to alkylating agents was 50% in G3 WD-panNETs and 50% in PDNEC. Conclusions Both G3 WD-panNETs and PDNEC responded to platinum and alkylating agents. Overall survival was significantly greater in G3 WD-panNETs compared with PDNEC. These findings challenge current classification and suggest that G3 panNENs should be classified by morphology.

Systemic Therapies for Advanced Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors are an uncommon tumor type and compose 1% to 2% of all pancreatic neoplasms. They are rarely localized at presentation and are typically diagnosed in the presence of metastatic disease. The management poses a significant challenge because of the heterogeneous clinical presentations and varying degrees of aggressiveness. A variety of systemic therapies have been developed for the management of pancreatic neuroendocrine tumors, including somatostatin analogues, a select group of cytotoxic chemotherapy agents, and targeted or biological agents. This article reviews the available systemic therapy options for advanced pancreatic neuroendocrine tumors.

O6-Methylguanine DNA Methyltransferase Status Does Not Predict Response or Resistance to Alkylating Agents in Well-Differentiated Pancreatic Neuroendocrine Tumors

OBJECTIVES Alkylating agents have activity in well-differentiated pancreatic neuroendocrine tumors (WD panNETs). In glioblastoma multiforme, decreased activity of O-methylguanine DNA methyltransferase (MGMT) predicts response; in panNETs, MGMT relevance is unknown. METHODS We identified patients with WD panNETs treated with alkylating agents, determined best overall response by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, and performed MGMT activity testing. RESULTS Fifty-six patients were identified; 26 (46%) of the 56 patients experienced partial response, 24 (43%) of 56 experienced stable disease, and 6 (11%) of 56 experienced progression of disease. O-methylguanine DNA methyltransferase status was available for 36 tumors. For tumors with partial response, 10 (67%) of 15 were MGMT deficient, and 5 (33%) of 15 were MGMT intact. For tumors with stable disease, 7 (47%) of 15 were MGMT deficient, and 8 (53%) of 15 were MGMT intact. For tumors with progression of disease, 3 (50%) of 6 were MGMT deficient, and 3 (50%) of 6 were MGMT intact. CONCLUSIONS We observed response and resistance to alkylating agents in MGMT-deficient and MGMT-intact tumors. O-methylguanine DNA methyltransferase status should not guide alkylating agent therapy in WD panNETs.Objectives Alkylating agents have activity in well-differentiated pancreatic neuroendocrine tumors (WD panNETs). In glioblastoma multiforme, decreased activity of O6-methylguanine DNA methyltransferase (MGMT) predicts response; in panNETs, MGMT relevance is unknown. Methods We identified patients with WD panNETs treated with alkylating agents, determined best overall response by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, and performed MGMT activity testing. Results Fifty-six patients were identified; 26 (46%) of the 56 patients experienced partial response, 24 (43%) of 56 experienced stable disease, and 6 (11%) of 56 experienced progression of disease. O6-methylguanine DNA methyltransferase status was available for 36 tumors. For tumors with partial response, 10 (67%) of 15 were MGMT deficient, and 5 (33%) of 15 were MGMT intact. For tumors with stable disease, 7 (47%) of 15 were MGMT deficient, and 8 (53%) of 15 were MGMT intact. For tumors with progression of disease, 3 (50%) of 6 were MGMT deficient, and 3 (50%) of 6 were MGMT intact. Conclusions We observed response and resistance to alkylating agents in MGMT-deficient and MGMT-intact tumors. O6-methylguanine DNA methyltransferase status should not guide alkylating agent therapy in WD panNETs.

Complete Responses to Mitotane in Metastatic Adrenocortical Carcinoma—A New Look at an Old Drug

PURPOSE Based largely on reports that predate modern reporting standards, mitotane has been considered a systemic treatment option for both hormone control and antitumor control of metastatic adrenocortical cancer (ACC), although the therapeutic window is narrow. METHODS We searched electronic medical records to identify patients with metastatic ACC treated and prescribed single-agent mitotane at Memorial Sloan Kettering Cancer Center from March 15, 1989-September 18, 2015. Reference radiologists reviewed all imaging and determined efficacy according to Response Evaluation Criteria in Solid Tumors 1.1. Patient demographics, toxicities, and treatment outcomes were reviewed. Next-generation sequencing was performed in selected cases. RESULTS Thirty-six patients were identified. The mean age was 54 and 50% had functional tumors. Grade 3 or greater toxicities were documented in 16 out of 36 patients (44%) and 17% had documented long term adrenal insufficiency. Progression of the disease as the best response occurred in 30 out of 36 patients (83%) and one patient (3%) experienced clinical progression. Three patients achieved a complete response (CR) (8%), one patient achieved a partial response (3%), and one patient (3%) had stable disease after slow disease progression prior to initiation of therapy (durable for 6 months). All responders had nonfunctional tumors. Next-generation sequencing in two of the three CR patients was performed and failed to identify any novel alterations. CONCLUSION In this retrospective series, mitotane had a low response rate and low tumor control rate; however, a disproportionately high complete response rate suggested it should be used in selected individuals. Adrenal insufficiency is common with mitotane use and aggressive treatment with steroid supplementation should be considered when appropriate to avoid excess toxicities. Biomarkers are desperately needed to further define this disease. IMPLICATIONS FOR PRACTICE This is the first objective report of single-agent mitotane using modern objective criteria. Although the vast majority of patients did not respond (and toxicity was high), we identified a remarkable 8% complete response rate (i.e. cure) in biopsy proven stage IV adrenocortical cancer patients. Biomarkers are desperately needed for this rare disease.

Current clinical trials of targeted agents for well-differentiated neuroendocrine tumors.

Abstract Neuroendocrine tumors (NETs) are a group of tumors originating in various locations, including the gastrointestinal tract, lung, and pancreas. Clinical trial design and disease management of these tumors pose a significant challenge because of the heterogeneous clinical presentations and varying degrees of aggressiveness. The recent completion of several phase II and III trials demonstrates that rigorous investigation of novel agents can lead to practice-changing outcomes. Furthermore, the molecular and genetic understanding of NETs has dramatically improved during the last few years; as a result, investigators have shifted clinical trial design to focus on targeted therapies. Most of these trials have targeted the somatostatin, vascular endothelial growth factor, and mammalian target of rapamycin pathways. This review will discuss the NET treatment landscape and trials of targeted agents currently offered.

Real-Time Genomic Characterization of Metastatic Pancreatic Neuroendocrine Tumors Has Prognostic Implications and Identifies Potential Germline Actionability

Purpose We assessed the usefulness of real-time molecular profiling through next-generation sequencing (NGS) in predicting the tumor biology of advanced pancreatic neuroendocrine tumors (panNETs) and in characterizing genomic evolution. Methods Patients with metastatic panNETs were recruited in the routine clinical practice setting (between May 2014 and March 2017) for prospective NGS of their tumors as well as for germline analysis using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) sequencing platform. When possible, NGS was performed at multiple time points. Results NGS was performed in 96 tumor samples from 80 patients. Somatic alterations were identified in 76 of 80 patients (95%). The most commonly altered genes were MEN1 (56%), DAXX (40%), ATRX (25%), and TSC2 (25%). Alterations could be defined in pathways that included chromatin remodeling factors, histone methyltransferases, and mammalian target of rapamycin pathway genes. Somatic loss of heterozygosity was particularly prevalent (50 of 96 samples [52%]), and the presence of loss of heterozygosity resulted in inferior overall survival (P < .01). Sequencing of pre- and post-treatment samples revealed tumor-grade progression; clonal evolution patterns were also seen (molecular resistance mechanisms and chemotherapy-associated mutagenesis). Germline genetic analysis identified clinically actionable pathogenic or likely pathogenic variants in 14 of 88 patients (16%), including mutations in high-penetrance cancer susceptibility genes (MEN1, TSC2, and VHL). Conclusion A clinical NGS platform reveals pertubations of biologic pathways in metastatic panNETs that may inform prognosis and direct therapies. Repeat sequencing at disease progression reveals increasing tumor grade and genetic evolution, demonstrating that panNETs adopt a more aggressive behavior through time and therapies. In addition to frequent somatic mutations in MEN1 and TSC2, germline mutations in these same genes underlie susceptibility to panNETs and highlight the need to re-evaluate whether germline genetic analysis should be performed for all patients with panNETs.

BRAF mutations in patients with large cell neuroendocrine carcinoma of the colon (LCNECC).

567 Background: LCNECC is a rare, poorly differentiated neoplasm with a median survival of 13 months. The cell of origin, genetic mediators and optimal clinical management of LCNECC are unknown. Current guidelines recommend treatment with platinum and etoposide, but nearly all patients rapidly fail therapy. Identification of actionable genomic alterations in LCNECC may lead to improved outcomes. Methods: We identified 123 patients (1.1%) with LCNECC or non-small cell high-grade neuroendocrine carcinoma of the colon or rectum, out of 11134 colorectal cancers treated at MSKCC from 1991-2015. Genomic testing had been performed on 8 tumors: 5 using mass spectrometry based genotyping of 8 genes and 3 using hybridization exon capture of 341 cancer-associated genes (MSK IMPACT). Results: BRAF V600E mutations were identified in 5/8 (62.5%) LCNECCs. One patient each had KRAS Q61H and G12V mutations. Only 2/8 patients had TP53 mutations. All 5 patients with BRAF V600E mutations had non-regional lymphadenopathy, con...