Next-generation sequencing (NGS) is of great benefit to clinical practice in terms of identifying genetic alterations. This study aims to clarify the gene background and its influence on thyroid tumor in Chinese population. NGS data and corresponding clinicopathological features (sex, age, tumor size, extrathyroidal invasion, metastasis, multifocality and TNM stage) were collected and analyzed retrospectively from 2844 individual thyroid tumor samples during July 2021 to August 2022. 2337 (82%) of the cohort possess genetic alterations including BRAF (71%), RAS (4%), RET/PTC (4%), TERT (3%), RET (2.2%) and TP53 (1.4%). Diagnostic sensitivity before surgery can be significantly increased from 0.76 to 0.91 when cytology is supplemented by NGS. Our results show that BRAF positive papillary thyroid cancer (PTC) patients tend to have elder age, smaller tumor size, less vascular invasion, more frequent tumor multifocality and significantly higher cervical lymph node metastatic rate. Mutation at RET gene codon 918 and 634 is strongly correlated with medullary thyroid cancer (MTC), However it did not display more invasive clinical characteristics. TERT positive patients are more likely to have elder age, larger tumor size, more tumor invasiveness, and more advanced TNM stage, indicating poor prognosis. Patients with TERT, RET/PTC1 and CHEK2 mutation are more susceptible to lateral lymph node metastasis. In conclusion. NGS can be a useful tool which provides practical gene evidence in the process of diagnosis and treatment in thyroid tumors.

A new subcategory, grade 3 neuroendocrine tumors, is incorporated into the grading system of pancreatic neuroendocrine neoplasms in the 2017 WHO classification in order to differentiate grade 3 neuroendocrine tumors from neuroendocrine carcinomas. The 2019 WHO classification extends the concept of grade 3 neuroendocrine tumors to gastrointestinal high-grade neuroendocrine neoplasms. However, there is still limited study focusing on the gastric grade 3 neuroendocrine tumors and gastric neuroendocrine carcinomas. We retrospectively enrolled 151 gastric high-grade neuroendocrine neoplasms patients, who underwent radical resection from January 2007 to December 2015. Clinicopathologic and prognostic features were studied. The Surveillance, Epidemiology, and End Results (SEER) database was used to verify the prognostic determinants found in the Zhongshan cohort. Neuroendocrine carcinomas showed a higher Ki67 index and higher mitotic count than grade 3 neuroendocrine tumors. We identified 109 (72.2%) patients with neuroendocrine carcinomas, 12 (7.9%) patients with grade 3 neuroendocrine tumors, and 30 (19.9%) patients with mixed neuroendocrine-non-neuroendocrine neoplasms. Although neuroendocrine carcinomas demonstrated higher Ki67 index (P = 0.004) and mitoses (P = 0.001) than grade 3 neuroendocrine tumors, their prognosis after radical resection did not demonstrate significant differences (P = 0.709). Tumor size, perineural invasion, and TNM stage were independent prognostic factors of gastric high-grade neuroendocrine neoplasms.