O’Dorisio, Thomas M.

AbstractThis article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Abstract Neuroendocrine tumors (NETs) arise from enterochromaffin cells found in neuroendocrine tissues, with most occurring in the gastrointestinal tract. The global incidence of NETs has increased in the past 15 years, likely due to better diagnostic methods. Small-bowel NETs are frequently associated with carcinoid syndrome (CS). Carcinoid syndrome diarrhea occurs in 80% of CS patients and poses a substantial symptomatic and economic burden. Patients with CS diarrhea frequently suffer from diarrhea and flushing and report corresponding impairment in quality of life, requiring substantial changes in daily activities and lifestyle. Treatment paradigms range from surgical debulking to liver-directed therapies to treatment with somatostatin analogs, nonspecific anti-diarrheal agents, and a tryptophan hydroxylase inhibitor. Other causes of diarrhea, including steatorrhea, short bowel syndrome, and bile acid malabsorption, should be considered in NET patients with refractory diarrhea. More therapeutic options are needed for symptomatic management of patients with NETs, and better understanding of the pathophysiology can empower clinicians with improved patient care.

Clusterin, a widely expressed, tissue-specific glycoprotein, is a diagnostic marker of several tumor types, including anaplastic large cell lymphoma, follicular dendritic cell sarcoma, and tenosynovial giant cell tumor. A recent study has suggested it is highly expressed by well-differentiated neuroendocrine tumors (NET) arising at most anatomic sites, with the exception of jejunoileal tumors, and that it is similarly not expressed by poorly differentiated neuroendocrine carcinomas (NEC). We sought to validate this result in a large cohort of NETs and NECs. Clusterin immunohistochemistry was performed on tissue microarrays of 255 NETs [45 lung, 4 stomach, 8 duodenum, 75 pancreas (62 primary, 13 metastatic), 107 jejunoileum (69 primary, 38 metastatic), 16 appendix] and 88 NECs (43 visceral, 45 Merkel cell). Extent (%) and intensity (0, 1+, 2+, 3+) of staining were assessed and an H-score (extent x intensity) calculated. An average H-score >5 was considered positive. Clusterin expression was noted in 82.4% of 148 nonjejunoileal NETs (average H-score 183) and only 8.4% of 107 jejunoileal NETs (average H-score, 31), as well as 19.3% of NECs (average H-score, 36). Clusterin is frequently, strongly expressed by NETs of diverse anatomic sites, with the exception of jejunoileal tumors, in which it is only rarely, weakly expressed. It is occasionally, weakly expressed by NECs. Most metastatic NETs of occult origin arise in the pancreas or the jejunoileum. For cases in which an initial site of origin immunopanel (eg, islet 1, PAX6, CDX2) is ambiguous, addition of clusterin may be diagnostically useful, with absence of expression suggesting a jejunoileal origin.

AbstractIntroduction.The incidence of colorectal neuroendocrine tumors (NETs) is increasing, and patients with this disease have particularly poor prognoses. Treatment options are limited, and survival times have not improved in the past decade.Methods.A post hoc analysis of the efficacy and tolerability of everolimus plus octreotide long-acting repeatable (LAR) was conducted in patients with colorectal NETs enrolled in the phase III RAD001 in Advanced Neuroendocrine Tumors, Second Trial (RADIANT-2) study. The primary endpoint (progression-free survival [PFS]), secondary endpoints (including objective response rate), and safety were assessed.Results.Patients with colorectal NETs receiving everolimus plus octreotide LAR had a significantly longer median PFS (29.9 months; n = 19) than did those receiving placebo plus octreotide LAR (6.6 months; n = 20). Everolimus plus octreotide LAR treatment also significantly reduced the risk for disease progression (hazard ratio: 0.34; 95% confidence interval: 0.13–0.89; p = .011). Although no objective responses were observed, tumor shrinkage was more frequently noted in the everolimus plus octreotide LAR arm than in the placebo plus octreotide LAR arm (67% vs. 37%, respectively). The combination of everolimus plus octreotide LAR was generally well tolerated by patients with colorectal NETs; rash and stomatitis were the most commonly reported adverse events.Conclusions.Everolimus plus octreotide LAR treatment had significant benefits and improved outcomes for patients with advanced colorectal NETs compared with placebo plus octreotide LAR treatment. Results of this exploratory analysis are consistent with those reported from the RADIANT-2 primary analysis. These findings support additional investigations of everolimus plus octreotide LAR in patients with colorectal NETs.

Purpose No established treatment exists for pancreatic neuroendocrine tumor (NET) progression after failure of chemotherapy. Everolimus (RAD001), an oral inhibitor of mammalian target of rapamycin, in combination with octreotide has demonstrated encouraging antitumor activity in patients with NETs. Patients and Methods This open-label, phase II study assessed the clinical activity of everolimus in patients with metastatic pancreatic NETs who experienced progression on or after chemotherapy. Patients were stratified by prior octreotide therapy (stratum 1: everolimus 10 mg/d, n = 115; stratum 2: everolimus 10 mg/d plus octreotide long-acting release [LAR], n = 45). Tumor assessments (using Response Evaluation Criteria in Solid Tumors) were performed every 3 months. Chromogranin A (CgA) and neuron-specific enolase (NSE) were assessed monthly if elevated at baseline. Trough concentrations of everolimus and octreotide were assessed. Results By central radiology review, in stratum 1, there were 11 partial responses (9.6%), 78 patients (67.8%) with stable disease (SD), and 16 patients (13.9%) with progressive disease; median progression-free survival (PFS) was 9.7 months. In stratum 2, there were two partial responses (4.4%), 36 patients (80%) with SD, and no patients with progressive disease; median PFS was 16.7 months. Patients with an early CgA or NSE response had a longer PFS compared with patients without an early response. Coadministration of octreotide LAR and everolimus did not impact exposure to either drug. Most adverse events were mild to moderate and were consistent with those previously seen with everolimus. Conclusion Daily everolimus, with or without concomitant octreotide LAR, demonstrates antitumor activity as measured by objective response rate and PFS and is well tolerated in patients with advanced pancreatic NETs after failure of prior systemic chemotherapy.

Purpose To update and expand on previously published clinical practice guidelines for the treatment of cancer treatment-induced diarrhea. Methods An expert multidisciplinary panel was convened to review the recent literature and discuss recommendations for updating the practice guidelines previously published by this group in the Journal of Clinical Oncology in 1998. MEDLINE searches were performed and the relevant literature published since 1998 was reviewed by all panel members. The treatment recommendations and algorithm were revised by panel consensus. Results A recent review of early toxic deaths occurring in two National Cancer Institute-sponsored cooperative group trials of irinotecan plus high-dose fluorouracil and leucovorin for advanced colorectal cancer has led to the recognition of a life-threatening gastrointestinal syndrome and highlighted the need for vigilant monitoring and aggressive therapy for this serious complication. Loperamide remains the standard therapy for uncomplicated cases. However, the revised guidelines reflect the need for recognition of the early warning signs of complicated cases of diarrhea and the need for early and aggressive management, including the addition of antibiotics. Management of radiation-induced diarrhea is similar but may not require hospitalization, and chronic low- to intermediate-grade symptoms can be managed with continued loperamide. Conclusion With vigilant monitoring and aggressive therapy for cancer treatment-induced diarrhea, particularly in patients with early warning signs of severe complications, morbidity and mortality may be reduced.