Our findings provide additional support for the National Comprehensive Cancer Network (NCCN) guidelines that categorize TNT as a viable treatment strategy for rectal cancer. Our data suggest that TNT facilitates delivery of planned systemic therapy. Long-term follow-up will determine if this finding translates into improved survival. In addition, given its high CR rate, TNT may facilitate nonoperative treatment strategies aimed at organ preservation.
The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Neuroendocrine and Adrenal Gland Tumors focus on the diagnosis, treatment, and management of patients with neuroendocrine tumors (NETs), adrenal tumors, pheochromocytomas, paragangliomas, and multiple endocrine neoplasia. NETs are generally subclassified by site of origin, stage, and histologic characteristics. Appropriate diagnosis and treatment of NETs often involves collaboration between specialists in multiple disciplines, using specific biochemical, radiologic, and surgical methods. Specialists include pathologists, endocrinologists, radiologists (including nuclear medicine specialists), and medical, radiation, and surgical oncologists. These guidelines discuss the diagnosis and management of both sporadic and hereditary neuroendocrine and adrenal tumors and are intended to assist with clinical decision-making. This article is focused on the 2021 NCCN Guidelines principles of genetic risk assessment and counseling and recommendations for well-differentiated grade 3 NETs, poorly differentiated neuroendocrine carcinomas, adrenal tumors, pheochromocytomas, and paragangliomas.
Purpose Most well-differentiated neuroendocrine tumors (WD-NETs) of the enteropancreatic system are low-intermediate grade (G1,G2). Elevated proliferation demonstrated by either a brisk mitotic rate (>20/10 high power fields) or high Ki67 index (>20%) defines a group of aggressive neoplasms designated as high grade (G3) neuroendocrine carcinoma (NEC). High grade NEC is equated with poorly-differentiated NEC (PD-NEC) and is associated with a dismal outcome. Progression of WD-NETs to a high grade neuroendocrine neoplasm very rarely occurs and their clinicopathologic and molecular features need to be characterized. Methods We investigated the 31 cases of WD-NETs with evidence of component of a high grade neoplasm. The primary sites included pancreas, small bowel, bile duct, and rectum. Histopathology of the cases was retrospectively reviewed and selected immunohistochemistry and gene mutation analyses performed. Results The high grade component occurred either within the primary tumor (48%) or at metastatic sites (52%). The clinical presentation, radiographic features, biomarkers, and the genotype of these WD-NETs with high grade component remained akin to those of G1-G2 WD-NETs. The median disease specific survival (DSS) was 55 months (16-119 months), and 2-year and 5-year DSS was 88% and 49%, respectively – significantly better than that of a comparison group of true PD-NEC (DSS 11 months). Conclusion Mixed grades can occur in WD-NETs, which are distinguished from PDNECs by their unique phenotype, proliferative indices, and the genotype. This phenomenon of mixed grade in WD-NET provides additional evidence to the growing recognition that the current WHO G3 category contains both WD-NETs as well as PDNECs.
Background In the pancreas, poorly differentiated neuroendocrine carcinomas include small cell carcinoma and large cell neuroendocrine carcinoma and are rare; data regarding their pathologic and clinical features are very limited. Design One hundred and seven pancreatic resections originally diagnosed as poorly differentiated neuroendocrine carcinomas were reassessed using the classification and grading (mitotic rate/Ki67 index) criteria put forth by the WHO in 2010 for the gastroenteropancreatic system. Immunohistochemical labeling for neuroendocrine and acinar differentiation markers was performed. Sixty-three cases were reclassified, mostly as well differentiated neuroendocrine tumor or acinar cell carcinoma, and eliminated. The clinicopathologic features and survival of the remaining 44 poorly differentiated neuroendocrine carcinomas were further assessed. Results The mean patient age was 59 years (range, 21–82) and the male/female ratio was 1.4. Twenty-seven tumors were located in the head of the pancreas, 3 in the body and 11 in the tail. The median tumor size was 4 cm (range, 2–18). Twenty-seven tumors were large cell neuroendocrine carcinomas and 17 were small cell carcinomas (mean mitotic rate, 37/10 HPF and 51/10 HPF; mean Ki67 index, 66% and 75%, respectively). Eight tumors had combined components, mostly adenocarcinomas. In addition, 2 tumors had components of well differentiated neuroendocrine tumor. Eighty-eight percent of the patients had nodal or distant metastatic disease at presentation and an additional 7% developed metastases subsequently. Follow-up information was available for 43 patients; 33 died of disease with a median survival of 11 months (range, 0–104); 8 were alive with disease, with a median follow-up of 19.5 months (range, 0–71). The 2-year and 5-year survival rates were 22.5% and 16.1%, respectively. Conclusion Poorly differentiated neuroendocrine carcinoma of the pancreas is a highly aggressive neoplasm, with frequent metastases and poor survival. Most patients die within less than a year. Most (61%) are large cell neuroendocrine carcinomas. Well differentiated neuroendocrine tumor and acinar cell carcinoma are often misdiagnosed as poorly differentiated neuroendocrine carcinoma, emphasizing that diagnostic criteria need to be clearly followed to ensure accurate diagnosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.