Mercury monitoring in the coastal areas of the Republic of Korea using the black-tailed gull egg as an indicator.

In the southeast and east coasts of the Republic of Korea, it is essential to monitor mercury accumulation in coastal organisms in view of the higher mercury distribution in sediments and human samples. However, mercury pollution monitoring in organisms, especially higher trophic-level organisms that can exhibit high mercury accumulation, is limited. Here, we examined the applicability of the eggs of the black-tailed gull (Larus crassirostris), which belongs to a high trophic level, for mercury monitoring in coastal areas. Breeding sites were selected in West, Southeast, and East Seas with different mercury concentrations in other matrices (sediment and biological samples of residents). The 5-year mean total mercury concentration in eggs collected during the breeding seasons from 2016 to 2020 was lower in Baengnyeongdo (705 ± 81 ng/g dry weight (dry), West Sea) than in Hongdo (1,207 ± 214 ng/g dry, Southeast Sea) and Ulleungdo (1,095 ± 95 ng/g dry, East Sea). The different patterns of mercury concentration in gull eggs among the breeding sites was consistent with those in the other matrices among the coastal areas. These results support the applicability of the black-tailed gull egg as an indicator for establishing a monitoring framework in the coastal areas of the Republic of Korea.

Comparison of Prophylactic Effects between Localized Biomimetic Minocycline and Systematic Amoxicillin on Implants Placed Immediately in Infected Sockets.

This study evaluated the prophylactic effect of localized biomimetic minocycline and systemic amoxicillin on immediate implant placement at infected extraction sites. Twelve mongrels with six implants each were randomly assigned to five groups: uninfected negative control (Group N); infected with oral complex bacteria (Group P); infected and treated with amoxicillin one hour before implant placement (Group A); infected and treated with minocycline during implant placement (Group B); and infected and treated with amoxicillin one hour before implant placement and with minocycline during implant placement (Group C). Radiographic bone level, gingival index (GI), probing depth (PD), papillary bleeding index (PBI), and removal torque (RT) were recorded. There was no significant difference between Groups A, B, and C for bone loss. Group A showed the highest RT, the lowest PBI, and significantly lower GI and PD values than Group P. Group B exhibited significantly higher RT value than Group N and significantly smaller PD value than Group P at 6 w postoperatively. Localized minocycline could improve implant success by reducing bone loss and increasing RT and systemic amoxicillin could maintain the stability of the peri-implant soft tissue. However, combined use of these two antibiotics did not augment the prophylactic effect.

Intra-sinus rigid fixation of a resorbable barrier membrane to repair a large perforation of the sinus membrane: a technical note.

A resorbable barrier membrane is commonly used for the repair of perforated sinus membranes during sinus lifting surgeries. However, repairing largescale perforations poses challenges for clinicians as the protection and isolation of graft material remain uncertain. With this technique, we aimed to prevent graft material loss and subsequent sinus-related complications using intra-sinus rigid fixation of the resorbable barrier membrane in cases with a large perforation of the sinus membrane.

A rare case of chordoma cutis.

Chordoma is a rare locally aggressive bone malignancy that originates from the notochord. It typically involves the sacrococcygeal area, spheno-occipital region of the skull, and spine. Cutaneous involvement of chordoma, termed as chordoma cutis, is uncommon and usually occurs via direct invasion or local recurrence. Distant metastasis to the skin is very rare. We report a case of chordoma cutis on the scalp, which lacked characteristic physaliferous cells but tested positive for brachyury, thus supporting the diagnosis of chordoma cutis. The patient, who presented with a solitary translucent nodule on the scalp, was previously diagnosed with chordoma on the vertebral column and skull 8 months prior. Microscopic examination showed a cord-like arrangement of plasmacytoid cells within a myxoid stroma. Physaliferous cells were not observed, and cytokeratin AE1/AE3 staining was negative; however, brachyury and epithelial membrane antigen staining was positive, leading to the diagnosis of chordoma cutis. Therefore, clinicians must include chordoma cutis in the differential diagnosis of translucent nodular lesions on the skin of patients formerly diagnosed with chordoma.

TissueGene-C induces long-term analgesic effects through regulation of pain mediators and neuronal sensitization in a rat monoiodoacetate-induced model of osteoarthritis pain.

OBJECTIVE: TissueGene-C (TG-C), a combination of human allogeneic chondrocytes and irradiated GP2-293 cells engineered to overexpress transforming growth factor-ß1 (TGF-ß1), has been developed as a novel cell-based gene therapy and a candidate for disease modifying osteoarthritis drug (DMOAD). We aim to investigate analgesic mechanism of TG-C in a pre-clinical animal model with monoiodoacetate (MIA)-induced pain. DESIGN: We used a rat MIA model of osteoarthritis (OA) pain. We examined that TG-C can regulate pain by inhibiting the upregulation of various pain mediators in both knee joint tissue and dorsal root ganglia (DRG) (n = 112) and alleviating pain behavior (n = 41) and neuronal hyperexcitability in DRG (n = 60), afferent nerve fiber (n = 24), and spinal cord (n = 35). RESULTS: TG-C significantly alleviated pain-related behavior by restoring altered dynamic weight bearing and reduced mechanical threshold of the affected hindlimb. TG-C significantly suppressed the expression of nerve growth factor (NGF) and calcitonin gene-related peptide (CGRP) in inflamed joint tissue. TG-C significantly suppressed the upregulation of tropomyosin receptor kinase A (TrkA) and nerve injury/regeneration protein (GAP43) and activation of Iba1-positive microglial cells in DRG. TG-C significantly recovered neuronal hyperexcitability by restoring RMP and firing threshold and frequency of DRG neurons, attenuating firing rates of mechanosensitive C- or Aδ-nerve fiber innervating knee joint, and lowering increased miniature and evoked excitatory postsynaptic currents (mEPSCs and eEPSCs) in the spinal cord. CONCLUSION: Our results demonstrated that TG-C exerted potent analgesic effects in a rat MIA model of OA pain by inhibiting the upregulation of pain mediators and modulating neuronal sensitization.

The current state of the osteoarthritis drug development pipeline: a comprehensive narrative review of the present challenges and future opportunities.

In this narrative review article, we critically assess the current state of the osteoarthritis (OA) drug development pipeline. We discuss the current state-of-the-art in relation to the development and evaluation of candidate disease-modifying OA drugs (DMOADs) and the limitations associated with the tools and methodologies that are used to assess outcomes in OA clinical trials. We focus on the definition of DMOADs, highlight the need for an updated definition in the form of a consensus statement from all the major stakeholders, including academia, industry, regulatory agencies, and patient organizations, and provide a summary of the results of recent clinical trials of novel DMOAD candidates. We propose that DMOADs should be more appropriately targeted and investigated according to the emerging clinical phenotypes and molecular endotypes of OA. Based on the findings from recent clinical trials, we propose key topics and directions for the development of future DMOADs.

Somatic Mutations of TP53 Identified by Targeted Next-Generation Sequencing Are Poor Prognostic Factors for Primary Operable Breast Cancer: A Single-Center Study.

Few studies have reported on the clinical utility of targeted next-generation sequencing (NGS) for breast cancer in Korea. We retrospectively reviewed the targeted NGS data of 219 patients with breast cancer who underwent surgical resection between August 2018 and April 2021. Here, we described the mutational profiles of breast cancer and examined their prognostic implications. The most frequently mutated gene was PIK3CA (n = 97/219, 44.3%), followed by TP53 (n = 79/219, 36.1%), AKT1 (n = 23/219, 10.5%), and GATA3 (n = 20/219, 9.1%). TP53 mutations were associated with aggressive histologic features. We followed up for 31 (range, 1-39) months and observed 11 (5.0%) recurrences: nine were TP53 mutant and two were TP53 wild-type. Multivariable analysis revealed that TP53 mutation was an independent prognostic factor for recurrence (p = 0.012). Although no drug is currently available for TP53 mutations, it is valuable to know the mutational status of TP53 for the precise management of breast cancer.

PWWP2B promotes DNA end resection and homologous recombination.

Genome instability is one of the leading causes of gastric cancers. However, the mutational landscape of driver genes in gastric cancer is poorly understood. Here, we investigate somatic mutations in 25 Korean gastric adenocarcinoma patients using whole-exome sequencing and show that PWWP2B is one of the most frequently mutated genes. PWWP2B mutation correlates with lower cancer patient survival. We find that PWWP2B has a role in DNA double-strand break repair. As a nuclear protein, PWWP2B moves to sites of DNA damage through its interaction with UHRF1. Depletion of PWWP2B enhances cellular sensitivity to ionizing radiation (IR) and impairs IR-induced foci formation of RAD51. PWWP2B interacts with MRE11 and participates in homologous recombination via promoting DNA end-resection. Taken together, our data show that PWWP2B facilitates the recruitment of DNA repair machinery to sites of DNA damage and promotes HR-mediated DNA double-strand break repair. Impaired PWWP2B function might thus cause genome instability and promote gastric cancer development.

PIK3CA Mutation as Potential Poor Prognostic Marker in Asian Female Breast Cancer Patients Who Received Adjuvant Chemotherapy.

Background: The prognostic relevance of the PIK3CA mutation together with PD-L1, c-Met, and mismatch repair deficiency (dMMR) have not been fully investigated in Asian women with breast cancer (BC) who have undergone postoperative adjuvant chemotherapy. Methods: We analyzed PIK3CA mutations via peptide nucleic acid (PNA)-mediated real-time PCR assay, PD-L1/c-Met expression via immunohistochemistry (IHC), and microsatellite instability (MSI) status using PCR and IHC, in 191 resected BCs from 2008 to 2011. The Cancer Genome Atlas (TCGA) dataset for the involvement of the PIK3CA mutation with PD-L1/c-Met/MMR was explored. Results: The PNA clamp-mediated assay was able to detect the PIK3CA mutation in 1% of the mutant population in the cell line validation. Using this method, the PIK3CA mutation was found in 78 (49.4%) of 158 samples. c-Met and PD-L1 positivity were identified in 31.4 and 21.8% of samples, respectively, which commonly correlated with high histologic grade and triple-negative subtype. MSI/dMMR was observed in 8.4% of patients, with inconsistency between MMR IHC and the MSI PCR. The PIK3CA mutation exhibited a poor prognostic association regarding recurrence-free survival (RFS) in both overall and triple-negative BCs. In subgroup analyses, the PIK3CA-mutated tumors showed poorer RFS than the PIK3CA-wildtype within the c-Met-positive, MSS, triple-negative, or age onset <50 years subgroups, which showed a similar trend of association in TCGA data. Conclusions: PIK3CA mutation together with c-Met or dMMR/MSI status might be relevant to poor prognosis in BC subsets, especially in Asian women.

RNF43 and PWWP2B inhibit cancer cell proliferation and are predictive or prognostic biomarker for FDA-approved drugs in patients with advanced gastric cancer.

Background: Abnormal regulation of genes has been closely related to gastric cancer. The characterization of gastric cancer has necessitated the development of new therapeutics as well as the identification of prognostic markers to predict the response to novel drugs. In our study, we used RNA sequencing analyses to show that on gastric cancer tissues to identification of gastric cancer prognostic markers. We specifically chose to study RNF43 because it inhibits gastric cancer-related Wnt/ß-catenin signaling by interacting with Wnt receptors. PWWP2B was chosen because it is a gene which is downregulated in gastric cancer. Methods: Utilizing RNA sequencing analysis, we evaluated the mRNA expression profile in gastric cancer patients. Also, we used HAP1 cells which is a human near-haploid cell line derived from the male chronic myelogenous leukemia cell line KBM-7. These cell line has one copy of each gene, ensuring the edited allele will not be masked by additional alleles. We investigated the screening of 1,449 FDA-approved drugs in HAP1, HAP1 RNF43 KO and HAP1 PWWP2B KO cells. RNA sequencing data reveals that RNF43 and PWWP2B expression were down-regulated in recurrence gastric cancer patients. Next, we investigated the anti-cancer effects of selected drugs in RNF43 and PWWP2B down-regulated MKN45 gastric cancer cells and xenograft model. Results: Among these FDA-approved drugs, three drugs (docetaxel trihydrate, pelitinib and uprosertib) showed strong inhibitory effects in RNF43 KO cells and PWWP2B KO cells. In MKN45 xenograft model, tumor volumes were significantly reduced in the docetaxel trihydrate, uprosertib or pelitinib-treated group. Our data demonstrated that RNF43 and PWWP2B are a biomarker that predict recurrence of gastric cancer. Conclusions: Our findings suggest that docetaxel trihydrate, uprosertib and pelitinib could be used as novel therapeutic agents for the prevention and treatment of gastric cancer with a decrease in RNF43 and PWWP2B expression.

Silver Nanoparticles Induce Neutrophil Extracellular Traps Via Activation of PAD and Neutrophil Elastase.

Silver nanoparticles (AgNPs) are widely used in various fields because of their antimicrobial properties. However, many studies have reported that AgNPs can be harmful to both microorganisms and humans. Reactive oxygen species (ROS) are a key factor of cytotoxicity of AgNPs in mammalian cells and an important factor in the immune reaction of neutrophils. The immune reactions of neutrophils include the expulsion of webs of DNA surrounded by histones and granular proteins. These webs of DNA are termed neutrophil extracellular traps (NETs). NETs allow neutrophils to catch and destroy pathogens in extracellular spaces. In this study, we investigated how AgNPs stimulate neutrophils, specifically focusing on NETs. Freshly isolated human neutrophils were treated with 5 or 100 nm AgNPs. The 5 nm AgNPs induced NET formation, but the 100 nm AgNPs did not. Subsequently, we investigated the mechanism of AgNP-induced NETs using known inhibitors related to NET formation. AgNP-induced NETs were dependent on ROS, peptidyl arginine deiminase, and neutrophil elastase. The result in this study indicates that treatment of 5 nm AgNPs induce NET formation through histone citrullination by peptidyl arginine deiminase and histone cleavage by neutrophil elastase.

Large field-of-view nanometer-sectioning microscopy by using metal-induced energy transfer and biexponential lifetime analysis.

Total internal reflection fluorescence (TIRF) microscopy, which has about 100-nm axial excitation depth, is the method of choice for nanometer-sectioning imaging for decades. Lately, several new imaging techniques, such as variable angle TIRF microscopy, supercritical-angle fluorescence microscopy, and metal-induced energy transfer imaging, have been proposed to enhance the axial resolution of TIRF. However, all of these methods use high numerical aperture (NA) objectives, and measured images inevitably have small field-of-views (FOVs). Small-FOV can be a serious limitation when multiple cells need to be observed. We propose large-FOV nanometer-sectioning microscopy, which breaks the complementary relations between the depth of focus and axial sectioning by using MIET. Large-FOV imaging is achieved with a low-magnification objective, while nanometer-sectioning is realized utilizing metal-induced energy transfer and biexponential fluorescence lifetime analysis. The feasibility of our proposed method was demonstrated by imaging nanometer-scale distances between the basal membrane of human aortic endothelial cells and a substrate.

Diffuse-Type Tenosynovial Giant Cell Tumor of the Tendon Sheath in Both Wrists.

Diffuse-type tenosynovial giant cell tumor (D-TSGCT), previously known as pigmented villonodular synovitis, is a locally aggressive neoplasm that may arise from the synovium, bursa, or tendon sheath. D-TSGCT is usually monoarticular and can be classified into intra- and extra-articular forms, the latter of which is rarer. Here, we report a case of D-TSGCT in a 64-year-old female that involved the entire flexor and extensor tendon sheaths of both wrists. We describe the ultrasonography and MRI findings, as well as review the relevant literature.

Significance of druggable targets (PD-L1, KRAS, BRAF, PIK3CA, MSI, and HPV) on curatively resected esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) still remains intractable disease with few therapeutic options. Programmed death-ligand 1 (PD-L1), which is essential for immune evasion, is involved in the pathogenesis of ESCC and thus is a potential therapeutic target. PIK3CA, KRAS, and BRAF mutations, microsatellite instability (MSI) caused by deficient mismatch repair (dMMR), and human papillomavirus (HPV) can potentially upregulate PD-L1 expression, which might contribute to the clinical outcome of patients with ESCC. METHODS: We investigated the significance of the present druggable markers [PD-L1, PIK3CA, KRAS, and BRAF mutations, MSI caused by deficient dMMR, and HPV] in 64 curatively resected ESCCs, using immunohistochemistry (PD-L1 and MMR protein expression), direct sequencing (KRAS, BRAF, and PIK3CA mutations), real-time PCR (HPV infection), and MSI using quasi-monomorphic markers. RESULTS: PD-L1 expression, PIK3CA mutation, and MSI/dMMR were detected in 35.9, 12.5, and 17.2% of ESCCs, respectively. HPV was rarely detected (1.6%) (high-risk HPV68), whereas KRAS and BRAF mutations were not detected in ESCCs. PD-L1-positive tumors were not correlated with PIK3CA mutation or MSI/dMMR (all P > 0.05). PD-L1, PIK3CA mutation, and MSI/dMMR characterized the patients associated with light smoking, female and younger age, and younger age and well-differentiated tumors, respectively (all P < 0.05). In multivariate analysis, only PD-L1-positivity was an independent favorable prognostic factor for overall survival (OS) and disease-free survival (DFS) (P = 0.023, P = 0.014). In the PD-L1-negative ESCCs, PIK3CA mutation had a poor prognostic impact on both OS and DFS (P = 0.006, P = 0.002). CONCLUSIONS: PIK3CA mutation may be an alternative prognostic biomarker in PD-L1-negative curatively resected ESCCs that can be optional to identify high-risk patients with worse clinical outcome who require more intensive therapy and follow-up.

TissueGene-C promotes an anti-inflammatory micro-environment in a rat monoiodoacetate model of osteoarthritis via polarization of M2 macrophages leading to pain relief and structural improvement.

Osteoarthritis (OA) is the most common form of arthritis, characterized by cartilage destruction, pain and inflammation in the joints. Existing medications can provide relief from the symptoms, but their effects on the progression of the disease are limited. TissueGene-C (TG-C) is a novel cell and gene therapy for the treatment of OA, comprising a mixture of human allogeneic chondrocytes and irradiated cells engineered to overexpress transforming growth factor-ß1 (TGF-ß1). This study aims to investigate the efficacy and mechanism of action of TG-C in a rat model of OA. Using the monosodium-iodoacetate (MIA) model of OA, we examined whether TG-C could improve OA symptoms and cartilage structure in rats. Our results showed that TG-C provided pain relief and cartilage structural improvement in the MIA OA model over 56 days. In parallel with these long-term effects, cytokine profiles obtained on day 4 revealed increased expression of interleukin-10 (IL-10), an anti-inflammatory cytokine, in the synovial lavage fluid. Moreover, the increased levels of TGF-ß1 and IL-10 caused by TG-C induced the expression of arginase 1, a marker of M2 macrophages, and decreased the expression of CD86, a marker of M1 macrophages. These results suggest that TG-C exerts a beneficial effect on OA by inducing a M2 macrophage-dominant micro-environment. Cell therapy using TG-C may be a promising strategy for targeting the underlying pathogenic mechanisms of OA, reducing pain, improving function, and creating a pro-anabolic micro-environment. This environment supports cartilage structure regeneration and is worthy of further evaluation in future clinical trials.

Ultrasound and MRI Findings of Giant Cell Fibroblastoma in the Abdominal Wall: Radiologic-Pathologic Correlations.

Giant cell fibroblastoma (GCF) is a rare soft-tissue sarcoma of fibroblastic origin. To the best of our knowledge, only one brief description of the MRI findings of GCF exists in the pathologic literature. Herein, we report a case of histologically proven GCF in a 3-year-old boy who underwent ultrasonography and MRI of a superficial mass in the abdominal wall.

BRAF and NRAS mutations and antitumor immunity in Korean malignant melanomas and their prognostic relevance: Gene set enrichment analysis and CIBERSORT analysis.

Cutaneous malignant melanomas (CMMs) are rare but are the cause of the highest skin cancer-related mortality in Korea. Very few studies have investigated the associations between KRAS, NRAS, BRAF, and PIK3CA mutations and TICs, as well as their prognostic impact on Korean CMMs. Peptide nucleic acid-mediated polymerase chain reaction clamping and Mutyper and immunohistochemistry were used to detect these mutations in 47 paraffinized CMMs. BRAF and NRAS mutations were detected in 21.3% and 12.8% of CMMs, respectively. No KRAS or PIK3CA mutations were identified. NRAS mutations correlated with low FOXP3 (regulatory T lymphocyte marker) and indoleamine 2,3-dioxygenase (IDO) (activated dendritic cell marker) TICs in CMMs, which is consistent with the negative correlation of regulatory T cells with NRAS mutations in TCGA data, while BRAF mutations were not associated with any TICs. In gene set enrichment analysis, BRAF and NRAS mutations were enriched in decreased CD8 (suppressor/cytotoxic T lymphocyte marker) T cell-linked and increased CD4 (helper/inducer T lymphocyte marker) T cell-linked gene signatures, respectively, confirming the trend in our cohort of associations only with NRAS. BRAF or NRAS mutations alone did not affect any prognosis. In the subgroup analyses, BRAF mutations, as well as high CD4, CD8, FOXP3, and IDO TICs, caused worse overall survival in NRAS-mutated melanoma. No correlation of CD163 (monocyte-macrophage-specific marker) was detected. We found that approximately one-third of our cohort had BRAF and NRAS mutations, none had KRAS or PIK3CA mutations, and most displayed decreased anti-tumor immunity. These findings may warrant further study on combined immunotherapeutic and molecular targeted therapy in Korean CMMs. Subgroup analyses according to TICs and BRAF/NRAS mutations may help to identify high-risk patients with worse prognoses.

Thyroid transcription factor-1 as a prognostic indicator for stage IV lung adenocarcinoma with and without EGFR-sensitizing mutations.

BACKGROUND: Thyroid transcription factor (TTF)-1 expression is a diagnostic marker and a good prognostic indicator for lung adenocarcinoma. However, its good prognostic ability might be due to epidermal growth factor receptor (EGFR)-sensitizing mutations as shown by the positive correlation between TTF-1 expression and EGFR mutations. We explored the prognostic impact of TTF-1 expression according to EGFR-sensitizing mutation status in lung adenocarcinoma patients. METHODS: We conducted a retrospective cohort study of patients with stage IV lung adenocarcinoma. Data were extracted from the lung cancer registry of Hallym University Medical Centers (three hospitals) in Korea between March 2006 and March 2016. RESULTS: Overall, 173 patients were included. EGFR-sensitizing mutations were detected in 84 (51.4%) patients. TTF-1 expression was positive in 139 (80.3%) patients; it was significantly correlated with EGFR-sensitizing mutations (p < 0.001). TTF-1-positive lung adenocarcinoma patients had longer overall survival (OS) than those who were TTF-1 negative (19.3 vs. 5.8 months, p < 0.001). In a Cox regression analysis, TTF-1 positivity, Stage IV M1a, good performance status, and EGFR-sensitizing mutations were independently associated with prolonged OS. In the subgroup of wild-type EGFR adenocarcinoma patients, TTF-1 positivity was also a good prognostic indicator for OS and progression-free survival (PFS) after first-line cytotoxic chemotherapy. CONCLUSIONS: TTF-1 expression was a good prognostic indicator for OS and PFS in stage IV lung adenocarcinoma patients with and without EGFR-sensitizing mutations.

Targeted next-generation sequencing of well-differentiated rectal, gastric, and appendiceal neuroendocrine tumors to identify potential targets.

Rectal neuroendocrine tumors (NETs) are the most common gastrointestinal (GI) NETs with an uncertain malignant potential despite their small size. There are limited data about driver mutations in rectal NETs, which may explain the tumors' unexpected behavior or common histologic morphology with other GI-NETs. Here, we investigated the clinically and pathologically relevant mutations of rectal and nonrectal NETs and compared the frequency and clinical significance of detected mutations between them. We sequenced 84 primary GI-NETs (69 rectal, 7 gastric, 5 appendiceal, and 3 sigmoid colon NETs) and 3 metastatic GI-NETs using targeted next-generation sequencing. Twenty-one rectal NETs (30.4%) showed at least 1 mutation in 24 cancer-related genes; the most common mutations were TP53 (10.1%) and FBXW7 (7.2%), of which 73% were pathogenic/likely pathogenic mutations. TP53 (p.R337C and p.R213*), PTEN (p.W111*, p.Q214*), CDKN2A (p.W110*), FBXW7 (p.R465H), and AKT1 (p.R23Q) were repetitive mutations found exclusively in rectal NETs, whereas SMAD4 (p.R361C) and STK11 (p.D176N) were repetitive mutations found only in gastric NETs. PTEN (p.G129K), EGFR (p.E709K), and KIT (p.V555I) were shared mutations between rectal and appendiceal NETs, whereas SMAD4 (p.R361C), ALK (p.G1202R), VHL (p.Q132*), and IDH1 (p.R132H) were concurrently detected between rectal and gastric NETs. GI-NETs with higher histologic grades, lymphovascular invasion, or recurrence tended to have higher numbers of mutation variants than other tumors; however, there was no significant difference. In conclusion, rectal NETs commonly carried pathogenic/likely pathogenic mutations. Because most mutations were identified in nonhotspot positions, next-generation sequencing is useful in identifying potential drug targets in rectal NETs.